E-Version INDIAN HIGHWAYS-JUNE 2015 EDITION

Transcription

The Indian Roads Congress
E-mail: [email protected]
Volume 43
Founded : December 1934
IRC Website: www.irc.org.in
Number 6
Contents
jUNE 2015
ISSN 0376-7256
4-5
From the Editor’s Desk - Road Transport and Safety Bill, 2014 at a Glance - Way Forward Towards Zero
Road Crash Fatalities Vision
6-11
Announcement for Pt. Nehru Award for 2012, 2013and 2014
Page
12
Technical Papers
Development of Need Based Approach for Supply System Planning with an International Review of Urban Transport
K.M. Lakshmana Rao
19
K. Jayasree
Limit State of Cracking for Reinforced Concrete Flexural Member as Per IRC:112-2011
Devang Patel
28
A Study on Porous Concrete Mixes for Rigid Pavements
A.U. Ravi Shankar
33
Tender Notice, RO, MORTH, Chhattisgarh
34
Tender Notice, MORTH, New Delhi
35
Tender Notice, NH Circle, PWD, Dehradun
36
Tender Notice, RO, MORTH, Lucknow
Jamnagar House, Shahjahan Road,
New Delhi - 110 011
Tel : Secretary General: +91 (11) 2338 4543
Sectt. : (11) 2338 7140, 2338 6274
Fax : +91 (11) 2338 1649
Nitendra Palankar
Kama Koti Marg, Sector 6, R.K. Puram
New Delhi - 110 022
Tel : Secretary General : +91 (11) 2618 5303
Sectt. : (11) 2618 5273, 2617 1548, 2671 6778,
2618 5315, 2618 5319, Fax : +91 (11) 2618 3669
No part of this publication may be reproduced by any means without prior written permission from the Secretary General, IRC.
Edited and Published by Shri S.S. Nahar on behalf of the Indian Roads Congress (IRC), New Delhi. The responsibility of the contents
and the opinions expressed in Indian Highways is exclusively of the author/s concerned. IRC and the Editor disclaim responsibility and
liability for any statement or opinion, originality of contents and of any copyright violations by the authors. The opinions expressed in
the papers and contents published in the Indian Highways do not necessarily represent the views of the Editor or IRC.
From the Editor’s Desk
ROAD TRANSPORT AND SAFETY BILL, 2014 AT A GLANCE WAY FORWARD TOWARDS ZERO ROAD CRASH FATALITIES VISION
S.S. Nahar
Dear Readers,
Govt. of India with the objective of saving two lakh lives in the first five years and to increase national GDP by 4% by improving
safety and efficiency of road transport has introduced the Road Transport and Safety Bill, 2014 in the Parliament in amendment to The
Motor Vehicle Act, 1988. Following are some key initiatives proposed (gist only) in the Bill:
Provision(s)
S. No.
Regulation(s)
*The Motor Vehicle Act,
1988 (existing)
Offence
(Violation)
Penalty
**The Road Transport and
Safety Bill, 2014(proposed)
Safer Road User
By Notification and traffic
signs (Sec.* 112)
Excessive speed
(Sec.* 183)
Fine upto Rs 1,000/LMV: Fine Rs5,000/- to Rs12,500/- (on 1st offence - varying
ranges);
1.
Limits of Speed
By Notification and traffic
signs (Secs.** 201, 202, 203)
Excessive speed
(varying ranges)
(Sec.** 299)
Fine Rs25,000/-; suspension of license (two weeks to six
months) and compulsory training (on subsequent offence)
HMV: Fine Rs10,000/- to Rs25,000/- (on 1st offence varying ranges);
Fine @ Rs50,000/-; suspension of license (three weeks to six
months) and compulsory training (on subsequent offence)
2.
3.
4.
5.
4
Racing and Trials of
Speed
Driving under the
influence of alcohol
and drugs
Wearing protective
Headgear
Seat belt
On written consent only (Sec.*
Sec.* 189
189)
Imprisonment upto one month or Fine upto Rs500/- or both
On written consent only
(Sec.** 207)
Sec.** 315
Fine
Rs10,000/(1st
offence);
Rs15,000/(2nd offence); Rs25,000/- (subsequent offence) and
imprisonment upto two weeks
Permissible limit [30 mg/
100 ml of blood (Sec.* 185)]
Sec.* 185
Imprisonment upto six months or Fine upto Rs2,000/- or both.
If committed within three years, imprisonment upto two years
or Fine upto Rs3,000/- or both
Permissible limit [30 mg/
100 ml of blood (Sec.** 208)]
Sec.**301
Fine Rs15,000/- on repeat upto Rs50,000/-or imprisonment
(six months) on repeat upto three years; suspension of license
(six months to one year/cancellation)
Mandatory except turbanwearing Sikhs (Sec.* 129)
Sec.*179
Fine upto Rs500/-
Mandatory except turbanwearing Sikhs (Secs.** 186
& 188)
Sec.** 309
Fine Rs2,500/-
Mandatory (Secs.** 194, 195
& 198)
Sec.** 308
Fine Rs5,000/-
INDIAN HIGHWAYS, jUNE 2015
EDITORIAL
6.
Driving License
Mandatory
(Secs.* 3 & 4)
Sec.* 181
Imprisonment upto three months or Fine upto Rs500/- or
both
Mandatory
[Secs.** 62 & 63
(automated & unified)]
Sec.**290
Fine Rs15,000/- to Rs25,000/- or imprisonment (three
months) or both
Mandatory to obey (Sec.* 119) Sec.* 177
7.
Mandatory Traffic
Signal
Fine:Rs5,000/- (1st offence);
Mandatory to obey
Sec.* 140
8.
Fine upto Rs100/- (1st offence) &
Rs300/- (subsequent offence)
Sec.**306
Sec.* 140
Rs 10,000/- (2nd offence);
Rs15,000/- (3rd offence) &
one month license suspension and compulsory training
Compensation: Rs50,000/- (on death);
Rs25,000/- (on permanent disablement)
Fine:Rs 1,00,000/- and imprisonment four years (on death);
Liability without fault
in certain cases
Secs.**
302 & 324
Rs3,00,000/- and imprisonment not less than seven years
(on death of child)
Rs1,00,000/- and imprisonment two years (on injury)
Logistics
9.
10.
By issue of permit
(Secs.* 113, 114 & 115)
Sec.* 194
By issue of permit
(Secs.** 215, 216 & 217)
Sec.** 304
Fine: Min. Rs2,000/- + Rs1,000/- per
Tonne excess + offloading charges
Fine: Rs10,000/- (two-wheeler);
Limits of Weight
Under notified Rules
(Secs.* 109, 110 & 111)
Construction and
Maintenance of
Vehicles
As per Code
(Sec.** 38)
Sec.* 182A
Sec.** 292
Rs25,000/- to Rs 50,000/- (LMV owner/consignor);
Rs50,000/- (HMV owner/consignor)
Fine: Rs1,000/- (1st offence);
Rs5,000/- (subsequent offence)
Fine: Rs5,00,000/- or imprisonment of three months or both
Fine:Rs2,000/-to Rs5,000/- (1st offence);
Mandatory
(Secs.* 39, 40 & 41)
11.
Sec.* 192
Vehicle Registration
Mandatory
(Secs.**85 & 88)
Rs5,000/- to Rs10,000/- +
imprisonment upto one year
(subsequent offence)
Fine:Rs25,000/- (1st offence);
Sec.** 294
Rs50,000/- (subsequent offence)
Rs1,00,000/- (delivering without registration)
Insurance
Mandatory
(Sec.* 146)
12.
Insurance
Mandatory
(Sec.** 229)
Sec.* 196
Imprisonment upto three months or Fine upto Rs1,000/- or
both
Fine:Rs10,000/- (two-wheeler);
Sec.** 305
Rs25,000/- (LMV);
Rs75,000/- (others)
* Source: e-site :www.tn.gov.in/sta/Mvact1988.pdf
** Source: e-site: www.prsindia.org/downloads/draft-bills/
It is construed that means to realize the desired objective(s) warranted to be preventive in nature being virtually with no side effect.
In pursuance to the spirit of preamble of our constitution and in recognition of indispensable Indian diversified socio-economic
structure, the preventive approach becomes imperative.
We are sincerely looking forward your worthy outlook, if any, a valued substance in our endeavor towards “collective wisdom” to
identify a sustainable Road Safety Action Plan.
“Arise! Awake! and stop not until the goal is reached” : Swami Vivekananda
Place : New Delhi
Dated : 27th May, 2015
(Sajjan Singh Nahar)
Secretary General
E-mail: [email protected]
5
Announcement for PT. Nehru Award For 2012
Nominations (in three hard copies alongwith a soft copy on [email protected]) are invited in the
prescribed proforma (Annex-1) for the IRC Pt. Jawaharlal Nehru Birth Centenary Award for the year
2012. The last date for receipt of nominations is 30.09.2015.
1. PREAMBLE
The award has been instituted by the IRC during Pt. Jawaharlal Nehru Birth Centenary Year to
encourage young (age less than 45 years as on 31.05.2013) and upcoming outstanding professionals
engaged in the field of Road Transportation/Highway/Bridge Engineering and related applied/
fundamental fields thereof (herein after, ‘the said field’).
2. NATURE OF AWARD
The Award will be in the form of Medal/Citation certificate and will be made for significant and
outstanding contribution in ‘the said field’.
3.ELIGIBILITY AND SELECTION OF THE AWARDEE
(i) Any young (age less than 45 years as on 31.05.2013) Engineer/Scientist or any citizen of India
engaged in ‘the said field’ and a Life Member/Ordinary Member/Student Member/Individual
Associate Member/Associate Member of IRC, who has made conspicuously significant
and outstanding contribution in ‘the said field’ in India during the preceding 5 years of the
nomination for the award i.e. between 31.5.2008 and 31.5.2013.
(ii) The basis of selection criteria will comprise the significant contribution by way of new innovative
approach or methodology for utilization of indigenously developed new technology/techniques
in resolving statutory issues like environmental related/non-renewable reserve of construction
material(s) and or present day knowledge of physical phenomenon or behaviour of relevance
to the professional approach and or addition, modification or improvement to extant design
made in either of the fields (a) Investigation Methods (b) R&D Management (c) Standardization
(d) Software Development (e) Planning (f) Maintenance (g) Repairs & Rehabilitation
(h) Environment (i) Highway Safety (j) Construction & Management (k) Protective Works
and (l) Traffic Engineering.
4. NOMINATIONS
Nominations shall be proposed duly filled in the prescribed proforma by either of the IRC Council
Member during the year 2015.
6
ANNEX - 1
PROFORMA FOR PT. NEHRU AWARD
(NOMINATION FOR THE YEAR 2012)
1. Name of the Nominee:
2. Roll. No. as member of IRC and the year since she/he is member of IRC:
3. Discipline under which to be considered:
4. Date of Birth (Attach authenticated Proof):
5. Academic qualifications beginning with Bachelor’s Degree:
6. Upto date Employment details including positions:
7. (a) Outstanding achievements of the nominee (in about 500 words) during the last 5 years
(i.e. between 31.5.2008 and 31.5.2013) (Attach separate sheet)
(b) Benefit derived/anticipated or measurable impact of the outstanding work/contribution/
achievement.
(c) Assessment by the sponsor about the importance of the contribution (not more than 100
words)
(i) Whether these achievements/contributions have already been recognized for awards by
any other Body. If so, the name of the Body, the name of award and the year of award
may be given.
(ii) Other awards/honours already received including fellowships of professional bodies.
8. Papers published, if any (reprints to be enclosed)/any work worthy to be mentioned in support of
claimed contribution(s).
9. Names & address of three renowned Indian experts in the areas of contribution:
(a)
(b)
(c)
10. Remarks (critical) of sponsoring Council Member in justification of her/his contribution of the
nominee (in about 100 words)
Date: _____________________
Place : __________________
Signature _____________________
Name & Designation of the Sponsor with Seal
(IRC Council Member during the year 2015)
7
1. PREAMBLE
2. NATURE OF AWARD
4. NOMINATIONS
8
ANNEX - 1
achievement.
words)
may be given.
(a)
(b)
(c)
Date: _____________________
Place : __________________
Signature _____________________
9
1. PREAMBLE
2. NATURE OF AWARD
4. NOMINATIONS
10
ANNEX - 1
achievement.
words)
may be given.
(a)
(b)
(c)
Date: _____________________
Place : __________________
Signature _____________________
11
DEVELOPMENT OF NEED BASED APPROACH for SUPPLY SYSTEM PLANNING
WITH AN INTERNATIONAL rEVIEW OF URBAN TRANSPORT
K.M. Lakshmana Rao* and K. Jayasree**
ABSTRACT
This paper presents an international review of urban transportation policies and identifies the gap in the supply system planning.
Demand management, supply system enhancement and system integration are the three core strategies to tackle urban mobility
problems and address functionality issues. An approach to supply system development has been developed from the concept of
demand deconcentration/decentralization.
1
INTRODUCTION
The problems which arise in
attempting to meet a given demand
with sustainable transport facility
indicate that transport policy and
planning are the two principal issues
which need to be addressed. In order
to tackle ongoing transport problems
- both at the urban and inter - urban
level - such as delay in travel, lack
of coordinated capacity, demand
concentration, congestion, pollution,
road accidents etc, a great deal of
attention has recently been paid to
new issues emerging in transport
system analysis. As a consequence,
innovative
models/methodologies
have been geared to create new tools
and technologies to cope with these
spatio - temporal transport changes in
transportation system analysis (from
both the demand and supply side).
The causes for these problems
are multifold ranging from low
operational performance of networks
to irregular land use planning. Major
urban problems consist of large
number of non conforming land uses
and structures resulting from the lag
in control of urban design behind
economic development. Structural
policies such as well planned transport
infrastructure expansion, planned
deconcentration and comprehensive
management of land use structure can
help in providing long term solution
to the urban transport problems but
they require careful coordination of
transport policies within a broader
city development strategy. This
work focuses on development of a
scientific approach in the design and
planning of road network to improve
the operational performance and
promote functional and hierarchal
connectivity.
Policy decisions and strategies to
solve the urban transport problems are
not adaptable to the economy and the
existing system. These decisions are
crucial for an economy as they change
the urban structure. Since transportation
policies seek to encourage the fullest
use of existing infrastructure before
committing substantial additional
capital investments, an approach to
design the supply system with optimal
utilization is attempted.
2
INTERNATIONAL Policy
Background
An overview of the current
International urban transport issues
and policies are presented below. The
review offers a critical assessment
of the contemporary efforts made
at different scales and in different
countries in trying to produce transport
policies which are politically, socially
and environmentally acceptable.
2.1 Dutch Urban Transport Policy
Dutch physical and transportation
planning practice is aimed at reducing
the growth in car mobility. The
spatial mobility policy (1960 - 1990)
was aimed to result in shorter travel
distances, and an increase in the use
of public transport and non-motorized
transport modes. The role for spatial
planning in policy from Transportation
Planning Perspective 1979-1995 was
to reduce the need for travel through
adequate coordination and integration
of areas for housing, jobs and services.
The policy intention for the National
Traffic and Transportation Plan
published in 2000 [NTTP 20001,
Ministry of Transport, Public Works
and Water Management (TPWWM)]
holds similar views on the relationship
between urban planning/urban form
and travel and transportation. The
focus is no longer on the reduction of
mobility, but on mobility management;
in other words, on finding ways to
accommodate the need for travel and
transportation while reducing their
negative impacts, such as pollution
and risk. Basically, these policies
can be divided into two categories:
policies that aim at controlling the
location of activities and policies that
aim at improving connections between
activities by different transport modes
(multi modal transport systems).
2.2Singapore Transport Policy
Singapore is one of the successful
cities in Asian cities on urban land
transport management. It has vibrant
economy, small land area, large
population, high demand on peak
hours and about 31% modal share
of cars. The review of urban policy
indicates an integrated approach
based on economic issues (Lim Lan
Yuan 19972). The solutions suggested
include supply system enhancement,
demand management linking demand
utility over a space, alternative urban
structures with decentralization of land
use and inter modal coordination.
2.3 China Transport Policy
The technological advancements in
developing country like China resulted
* Professor and Head, Department of Civil Engineering, JNTU College of Engineering, Hyderabad
** Assistant Professor, Department of Civil Engineering, Vasavi College of Engineering, Hyderabad
12
TECHNICAL PAPERS
in conditions of road congestion,
more average travel time, pollution,
accidents, confusion of transport
order, and lower usage rate of road
area. Supply enhancement measures
for addressing these problems
included road development covering
6.6 sq.m/person from 2.2 sq.m/person
and functional road development. The
strategies adopted could not succeed
in a congenial urban environment
in China due to lack of integrated
planning, unbalance in supply and
demand, unreasonable hierarchy in
transport structure making the transport
policy not adaptable to the system
(Wen Du 20033). Hence the counter
measures included policy decisions and
formulations on supply enhancement,
integrated strategies, traffic planning,
equilibrium of supply and demand,
traffic structure optimization for a
sustainable development.
2.4Seoul Transport Policy
Seoul’s transportation was focused on
surface trams in 1945 which shifted
to public transportation after 1960
comprising of rail, bus and taxis.
22% of the nation’s vehicles are
concentrated in Seoul with a travel
demand of 2.3 million vehicles per
day having 20.2% of roads in city
area. The Seoul transport policy has
been changing over last decades as
the traffic environment has changed.
Prime directions of the transport policy
(2000) are improvement of public
transport, effective control on private
cars, expansion of infrastructure
through
circular
and
radial
expressway construction, introduction
of Intelligent Transport Systems
(ITS), integration and coordination
of
transportation
systems
and
encouraging green travel modes
(Gyenchul Kim and Jeewook Rim
20004). The policies are directed
towards balanced application of
demand management and supply
management strategies. However,
the latter independently could not
mitigate the urbanization problems/
traffic congestion as new construction
of infrastructure generated additional
demand.
2.5 Indonesia Urban Transport
Policy
Indonesia’s population is rapidly
growing and rapid motorization has led
to dispersed settlement patterns, high
demand for travel, severe and growing
congestion and associated problems
of safety and pollution. Private car
ownership levels are still low and most
people depend on public Transport.
The policy statements eventually
covered the following; Institutional
Framework, Land Law, Central
and Local Government Funding,
Role of Private Sector, Integrated
Land Use and Transport Planning,
Travel demand Management, Traffic
Management, Infrastructures, Public
Transport, Safety, and Environmental
Management and Pollution Control
(Sutanto Soehodho 19995). On
infrastructure planning side, supply
system enhancement is integrated
with demand management to meet
the demand. Before undertaking new
construction, Government has ensured
the fullest use of existing infrastructure.
The overall transportation plan is
framed based on the road hierarchy
study. A road hierarchy review is
carried out for each city, to identify
shortcomings in the functional road
network. The country planning on
infrastructure is based on road utility
with a lead to enhancement of system
coordination.
2.6Russian Urban Transport
Policy
Russia’s urban population contributes
to 73.3% of the total nation’s
population and the capital of Russian
Federation, Moscow is reckoned to
be one of the 12 biggest cities in the
world. Urbanization has stopped
since 1980’s and the focus of
transportation policy has shifted from
meeting the demand to maintaining
the existing system and improving
the service operations. The current
strategies for sustainable development
are
improvement
of
existing
infrastructure, traffic management
control, improvement of transport
service quality, promotion of public
transport and green modes, use of
new technologies for better service
and efficiency, regular monitoring
and auditing of land use and
infrastructure through road user
tracking, introduction of ITS with
need based planning on environment
friendly transportation system (Vadim
Donchenko 2004).
2.7 VietNam Urban Transport
Policy
Vietnam is an Asian country separated
from China and is influenced by the
Chinese urban planning. The dominant
mode of transport in urban cities in
Vietnam is two wheeler traffic (56%)
and supply system configuration is
spread over 8% of the total area.
Rapid development has led to traffic
congestion and inadequate supply.
Key policy suggestions made for
sustainable development include
improvement of traffic management
strategies, public transport, supply
system enhancement providing road
network of 300 m/1000 people and
providing adequate infrastructure
facilities to cyclists and pedestrians
(Luu Duc Hai 2003).
2.8 Australian Urban Transport
Policy
Australian cities are low density
cities with high car ownership rates
and high trip lengths in the world.
The car dependency is about 95% in
urban areas and public transport is
less which makes the entire system
having less access to economic and
social activity. Moreover the land use
planning has assumed car dependence
and the prevailing taxation policies
encourage car ownership. Hence
policies and strategies were directed
towards improvement in access by
13
TECHNICAL PAPERS
public transport service. The policy
responses include funding strategies
for enhancing public transport utility,
development of transport infrastructure
to improve access, monitoring the
operations etc in the interest of social
advantage (Graham Curie 20091).
2.9United States Transport Policy
US transportation poses heavy chronic
congestion to 90% of the road users
who travel to work by car inspite of
low population density. Forty five
percent of the users have no public
transportation service options and
the congestion delays in metropolitan
areas add upto more than 4 billion
person hours to lost time each year.
1938 - 1956 was an era of enhancing
the supply system by constructing
new roads and highways. From
1991, focus has shifted to public
transport development and demand
management
strategies
through
congestion pricing. US Transport
Policy (2009) is directed to preserving
and enhancing the infrastructure
and systems that already exist. The
transportation system is centered
over Economic Growth, Connectivity,
Metropolitan Accessibility, Energy
Security
and
Environmental
Protection, Safety. The federal
programs are focused on ensuring
connectivity,
preserve
existing
metropolitan
systems
through
maintenance
and
improving
accessibility, expand the supply
capacity in metropolitan areas
(National
Transportation
Policy
Project NTPP 20092). Mobility and
Accessibility in the network is treated
as a function of connectivity with
user based conceptualization in US
transport policy.
2.10United Kingdom (UK) Urban
Transport Policy
UK is the fourth largest economy in
the world where the link between
traffic growth and economic growth
has weakened in recent years (UK
Transport Department Policy and
14
Planning, 20043). In the 1950s and
1960s, the first transport planning
strategies were developed aiming at
promoting use of the car through new
road construction and improvements
to existing congested pockets in
road network based on future traffic
prediction and policy measures. By
the mid-1970s, a new system of
transport planning was introduced
which
made
local
authorities
recognize other factors such as the
environment, land use and social
equality in access to transport. The
1980s was a decade of changing
policies with increasing public
awareness of environmental issues,
and this is probably linked with the
final few ‘first-generation’ motor
ways. In 1989, National Road Traffic
Forecasts predicted a 142% growth in
traffic levels between 1989 and 2025
which initiated the policy change
to alternate route development and
improve the existing supply system.
In 1994 ‘UK Strategy for Sustainable
Development’ and ‘Planning Policy
Guidance Note 13’ were released
addressing integrated transport and
land-use planning. In 2000, the
ten-year plan was published with
‘anti-car and anti-motorist label’ and
there was a shift in policy back, to
include road construction. The latest
policy change was made in 2004
which provides a balanced approach
in relieving congestion and provides
the strategy for the networks till 2030.
The policy aims to improve safety
in the network, deliver promptly
additional road capacity where it
is justified - balancing the needs of
motorists and other road users with
wider concerns about the impact
on the environment, including
the landscape; achieve greater
performance out of the road network
through
improved
management;
facilitate
smarter
individual
choices about the trips, giving
people alternatives to use their car,
particularly for short journeys; and
support and promote these choices by
ensuring that new ways of paying for
road use make practical options. The
strategy charts a course over the next
30 years by enhancing the capacity of
the road networks, introducing ITS
and adopting demand management
strategies by road pricing, carpooling
etc.
2.11 German Transport, Land Use
and Taxation Policies
Germany adopts a five folded
policy for transport sustainability
in Germany (Eco-Logica 20094).
Taxes and restrictions on car use,
provision of high-quality, and
well-coordinated public transport
services,
improvement
of
infrastructure
for
non-motorized
travel,
compact,
mixed-use
development, discouragement of
low-density suburban sprawl.
2.12Europe Transport Policy
European countries are facing a
decreasing trend of mass transport
utility from 60 - 70% to 20 - 25% with
98% of transport depending on oil.
Transport policies were made in 1995,
2001 and 2005. Policies in 1995 and
2001 were focused on infrastructure
requirements for improved mobility
and integration of system. European
Policy (1994) striked a balance
between economic development and
the quality and safety demands made
by society in order to develop a
modern,
sustainable
transport
system for 2010. Main strategies
were
intermodal
coordination,
corridor improvement, new demand
management strategies, use of green
technologies and effective transport
management strategies. The major
problems which were prevailing even
after the policy initiations in 2001
were congestion, safety, pollution,
lack of functional infrastructure,
public transport etc. A European
Union
National
Transportation
policy was framed for 2006 - 2025
(National Transport Policy for 2006-
TECHNICAL PAPERS
20255, Ministry of Infrastructure,
European Union, 2006) from social,
economic, spatial and ecological
aspects for a sustainable development
with substantial improvement of the
quality of transport system. The main
strategies for 2006 policy were
improvement
in
accessibility,
efficiency and transport quality,
development of integrated transport
system,
enhancing
safety
and
reducing the negative impact of
transport on the environment and
conditions of living. Majority
of the strategies for mobility
improvement were on supply system
with enhancement implementation
requisites through functional corridors
development,
alternative
path
development, better use of existing
infrastructure and traffic management.
3
National Policies and
Initiatives
India’s urban population is 30% of
its total population with only 16% of
road network in developed cities and
meeting the demand is the challenge
many Indian cities are facing. Public
transport systems have not been
able to solve the urban transportation
problems due to increase in
personalized mode of transport and
Intermediate para transit. The aspects
of an urban transport policy have
been articulated by a number of
committees and expert groups.
Important amongst them are the
recommendations of the Metropolitan
Transport Team (1970), the National
Transport Policy Committee (1980),
the study group on Alternative
Systems of Urban Transport (1987),
the Steering Committee of Transport
(1988) and National Commission
on Urbanization (1988). They have
all noted the growing urban travel
demand, stressed its importance for
the overall development and identified
a number of policies and programmes
for its development. Some of the
major urban transport initiatives are
presented below:
3.1Jawaharlal Nehru National
Urban
Renewal
Mission
(JNNURM) 2005
Jawaharlal Nehru National Urban
Renewal Mission (JNNURM) 2005
aims at encouraging reforms and
fast track planned development of
identified cities with a focus on
efficiency in urban infrastructure
and service delivery mechanisms,
community
participation
and
accountability of Urban Local Bodies
towards citizens. Redevelopment
of inner (old) city areas including
widening of narrow streets, shifting
of
industrial
and
commercial
establishments from non-conforming
(inner city) areas to conforming (outer
city) areas to reduce congestion,
urban transportation including roads,
highways, expressways, Mass Rapid
Transit Systems, and metro projects;
Parking lots and spaces on Public Private participation basis are some of
the key areas of JNNURM.
3.2 National Urban Transport
Policy
India
(NUTP,
Government of India 2006)
National Urban Transport Policy was
approved in 2006 to help in addressing
the unprecedented increase in transport
problems that the major cities in
the country are facing. It focuses on
the development, construction and
operation of better transport systems/
facilities to encourage public transport
and improve access of business to
markets and the various factors of
production. The major thrust areas
included integrated planning, a
rational share between public and
private modes, choice of appropriate
and relevant technology for public
transport systems, optimal use and
management of available resources
(road network and operating systems),
restructuring of monetary and fiscal
policies to encourage and promote
urban transport and establishment
of institutional arrangements, at all
levels of governance, particularly
at the city level, for the planning,
development, operation, management
and coordination of urban transport
systems.
3.3The 11th Five Year Plan on
Urban Transport by Planning
Commission (2007 - 2012)
Working Group for the 11th Five Year
Plan on Urban Transport, constituted
by the Planning Commission of
the Government of India in 2006
proposed an integrated land use and
transportation planning with land
use and transport interventions. The
11th plan has identified the need of
effective road network planning in a
systematic and hierarchical manner
which should aim at a topology
that provides alternative routes
of movement. The guidelines for
promoting a hierarchical road network
system were based on the population
of the urban area.
3.4 Traffic and Transportation
Policy and Strategy Studies for
Urban Areas in 2008
Traffic and Transportation Policies
and Strategies in Urban Areas in
India was conducted in 2008 to
update the transportation information
and projections made from the
previous study in 1998 and review
NUTP 2006. As a part of the study,
several performance evaluators were
developed such as accessibility index,
congestion index, walk ability index,
city bus supply index, safety index,
para- transit index, slow moving
vehicle index, on-street parking
interference index and transport
performance index. Small and
medium cities are planned for smooth
and safe traffic flow by ensuring
travel by non-motorized modes,
improvement/development of urban
roads, traffic management measures,
implementation of bus transport along
major corridors for cities without
public transport currently and
augmentation of bus services for cities
having PT in the next 20 years.
15
TECHNICAL PAPERS
3.5Smart Cities Concept
Government of India in 2014 has
announced an ambitious 100 smart
cities programme. State capitals,
and many tourist, heritage cities are
expected to witness a rapid upgrade
of urban infrastructure and online
services to citizens, enabled by
Information Technology. The key
features of a Smart City is in the
intersect between competitiveness,
Capital and Sustainability. The smart
cities should be able to provide
good infrastructure such as water,
sanitation, reliable utility services,
health care; attract investments;
transparent processes that make it
easy to run a commercial activities;
simple and on line processes for
obtaining approvals, and various
citizen centric services to make
citizens feel safe.
4
Discussion on Review
of International and
National Urban Transport Policies
An overview of the understanding of
current National and International
urban transport issues and policies are
presented below in the Table 1.
Table 1 Review of International and National Urban Transport Policies
S. No.
Country/
Region
Core Policy Issues - Supply and Demand
1
Dutch
Improvement of infrastructure by controlling the activity levels between/
among nodes
2
United States Demand - Supply - System Coordination based integrated approaches
analysed over spatio - temporal frames. Multifaceted objectives configures
and controls the land use permission and infrastructure development
3
United
Kingdom
Social equality, environment and land use are the hallmarks suggestive in
framing the urban policy
4
Indonesia
Road utility enhancement - Dynamic changes of demand by coordinating
existing infrastructure in an optimal manner
5
Germany
Compact and mixed use development - micro level land use transportation
planning
6
Europe
Demand management with sustainable networks
7
China
Infrastructure optimization through demand - supply equilibrium
8
Singapore
Supply system enhancement, Demand management, Integrated urban
planning
9
Seoul
System oriented planning - Balanced application of demand management
and supply management strategies
10
Russia
System oriented planning with need based development - Performance
evaluation and Operational improvements
11
Vietnam
Supply system enhancement with Index/Empirical based planning
12
Australia
Accessibility as main criteria with demand based planning by policies
orienting towards social benefits and intermodal coordination
13
India
Integrated transport and land use planning, Systems integration
Majority of the policies address an
integrated planning approach to
solve urban transportation problems
with a variety of supply enhancement,
demand management and system
integration techniques. The strategies
to achieve the policies are varied based
on the pace of economic development
which are well defined for demand
16
management and system integration.
Supply system enhancement strategies
include new construction approaches
and improvement to existing system
approaches. There are no scientific
approaches framed in the policy
guidelines for implementation of these
supply based strategies to enhance the
supply system capacity.
5
Approach To Demand
Deconcentration
Demand - Supply - System are the three
dimensional frames which configure
the directional growth of urbanization.
An ideal supply system must be
configured to meet the travel demand
and incorporate the change of land use
and socio - economic characteristics.
The spatial configuration of the
key elements of the supply system
(nodes, links, paths, network) act
as transitional fabric/surface for
disseminating and shaping the demand
profiles over time and space. These
transitional entities are often dynamic
in nature and are constantly subjected
to the change in functionality due
to the process of urbanization. For
example, a collector street transforms
to a sub-arterial/arterial street due to
increase in commercial activity in the
area. The non systematic planning and
orientation of the spatial configuration
of these entities makes the system to
be non functional and non hierarchical
posing a low operational performance
of the supply system. Non uniform
spread of demand over the supply
system due to the dynamics involved
in the user preferences, trip lengths,
trip
orientations
and
existing
undefined hierarchy and functionality
of the supply system leads to under
utilization of the supply system and
non uniform demand responsive
system. Moreover, constant changes
in demand created an imbalance in
land use and system characteristics
and vice versa. It is difficult to control
the dynamics of user preferences, trip
lengths and orientations as it involves
stringent urban policy decisions to the
immediate effect. But hierarchy of
the supply system can be defined and
controlled by properly spreading the
transitional entities uniformly. This
strategy inherently develops a touch
stone principle to make demand and
supply in equilibrium by development
of fractal/self similar transitional
fabric to disseminate the demand and
TECHNICAL PAPERS
deconcentrate it over time and space.
The planning can be done if the supply
system is assumed as merely a system
with no defined hierarchy and treating
the nodes and links as equal demand
transfer points. The user preferences
are then imposed on the supply
system to emerge a hierarchical
system of paths and links. This
hierarchical system shall be oriented
to develop a fractal system. When
demand and supply weigh uniformly
in the equilibrium condition and start
exceeding the break even point leading
to uneconomic travel, risk generation
and poor environment conditions,
transportation system coordination
with demand and supply can be
formulated.
6Lead to the Study
The objective of the study is to develop
a spatial configuration of the supply
system that generates equilibrium
between demand and supply systems.
The orientation and planning of the
spatial configuration must accept the
demand uniformly and similarly for
maintaining a controlled environment
in travel. The demand accepting supply
entities likes nodes, links, paths and
network must be disseminated uniformly
with a self similar characteristic. These
demand accepting supply entities would
be highly functional and hierarchical
compared to their counter parts in a
supply system due to the morphological
and topological characteristics of the
urban spatial supply system. Identifying
these transitional entities in a supply
system (network) and orienting to
match the neighborhood characteristics
is attempted with an analysis of
dynamic demand profiles over the static
network. The lead is extended from
the observation that the roads are non
functional, non hierarchical and treated
in static form when demand profiles
are configured on these with variable
trip lengths, trip orientations and trip
intensities over a time and space. To
achieve demand and supply equilibrium,
options that can be formulated fall into
two categories: a) Configuration of
the supply system to meet the demand
and b) Demand management to match
the supply configurations. The work
addresses the first strategy to achieve an
effective urbanization. The elements of
supply system configuration are shown
in the Fig. 1. Conventional practices for
demand - supply equilibrium focused on
location of origins, destinations, mode
split, route assignment, purpose of travel,
travel time etc. This approach attempts
an analysis with the harmonious demand
attainment variables in a network such
as trip intensity in terms of static utility
of nodes and links in a network, dynamic
traffic flows, trip orientation to signify
the travel interactions and patterns
between the traffic generating nodes, trip
lengths to signify the user preferences in
travel.
Fig. 1 Elements of Supply System
Orientation
7
CONCEPTUAL FRAMEWORK
The trend of policy sequence
formulations are varied in different
development scenarios and traffic
growths with a more independent and
parallel formulations of demand-supplysystem in developing and undeveloped
nations
and
integrated-subset
formulations in developed nations.
The study presents a strategic lead in
reducing the supply utility gap that
is observed in the sequence of urban
transport policy operations in developed
and developing countries that are in pace
with economic development of urban
area. Supply based planning involves
its
characterization/generalization,
evaluation and design. Supply system
characterization of static entities
(node, link, path, and network) through
topological formulations give a lead to
its evaluation and design. The evaluation
derives the need for the type of design
required for the existing development
patterns. The design of supply system
involves new infrastructure development
planning and existing infrastructure
reorientation planning to improve
operationality and sustenance among
environment, economy and social
aspects. Since supply system is often
subjected to under utilization in many
urban areas. The design for the supply
system optimal utility with existing
configuration constraint is formulated
through a planning framework of
network orientation that defines the
crucial/critical entities in performance
of network. Moreover, utilization of
existing infrastructure is important
than new construction. Hierarchy/
functionality of the supply system are
emerged with the critical components
that derive maximum supply utility
and promotes a fractal spatial structure.
This fractal system reduces travel costs
in urban areas and hence is necessary
to meet the demand. Derived and
existing supply entities are promoted
as a planning strategy that induces a
functional and sustainable environment
in an urban fabric. The planning strategy
for improving the existing functional
supply entities are designed through
prioritization analysis. Moreover, supply
based planning implementation must
consider the improvement of existing
functional elements for optimizing the
existing facilities.
Planning and Design of functional
entities of supply systems is considered
for the analysis as the topology of
functional roads has a more direct
and essential impact on overall travel
mobility of a road network than that of
less functional roads such as local streets
and also, since the functional network is
smaller than the whole road network and
demonstrates clearer patterns that are
easier to define and identify.
The policy framework for supply
infrastructure
that
has
been
conceptualized is given in Table 2.
17
TECHNICAL PAPERS
Table 2 Policy Framework for Supply Infrastructure
S. No.
Policy
Strategies
Implementation Requisites
1
Optimal utilization of existing infrastructure
Demand deconcentration and traffic
decentralization
2
Demand supply equilibrium
a) Fractal urban environment
a) Path similarity
b) Uniformity in transitional demand transfer to b) Node similarity
the supply
c) Integration of neighborhood networks
3
Operational performance improvement
Path utility and functional behavior assessment
8
Conclusion
An approach for spatial planning
and development of urban policy
for addressing urban transportation
problems is attempted in the study
from system wide perspective taking
account static network topology, urban
form and dynamic travel demand.
A lead to the urban policy on
demand - supply equilibrium ,
fractal form of supply system for
demand deconcentration, land use
dissemination,
integration
of
network neighborhoods, immediate
improvement
of
operational
performance of the supply system
18
are obtained from the study. These
efficient leads can produce urban
areas with a sustainable transport
environment by revitalizing the
existing supply system to meet the
demand. The research provides a
new dimension for the urban
transport policies, the strategies for
achieving the objectives and the
implementation techniques at field
level.
REFERENCES
1.
Graham Curie 2009. Australian Urban Transport and Social
Disadvantage.
The
Australian
Identification of functional road network
2.
3.
4.
5.
Path prioritization
Economic Review, Vol. 42, No. 2,
pp. 201-8.
National
Transportation
Policy
Project NTTP 2009. Report on
Performance Driven: A New Vision
for US Transport Policy. Bipartisan
Policy Centre.
UK Transport Department Policy
and Planning, 2004. The Future of
Transport - a Network for 2030.
Eco-Logica Ltd, 2009. World
Transport Policy and Practise.
European Transport Policy 1994,
European Commission. National
Transport Policy for 2006 - 2025,
Ministry of Infrastructure, European
Union, 2006.
LIMIT STATE OF CRACKING FOR REINFORCED CONCRETE
FLEXURAL MEMBER AS PER IRC:112-2011
Devang Patel*
Synopsis
The Latest Code for Bridge Design, IRC:112-2011 has introduced the Limit State Method of design. Accordingly the member is to be
checked for crack width under serviceability condition. The paper represents the basic theory and phenomenon of the crack width in
the RCC flexural member. The various clauses of the IRC:112-2011 pertaining to Crack width are also discussed. Two approaches for
crack control: 1) Crack width calculations and 2) Crack control without direct calculations are discussed at length. Numerical example
for use of those approaches is also presented.
1
GENERAL
This article pertains to the control of
flexural cracking in reinforced concrete
slabs & beams designed in accordance
with IRC:112-2011.
Cracking of concrete will occur
whenever the tensile strength of
the concrete is exceeded. This is
inevitable in normal reinforcedconcrete structures, and once formed,
the cracks will be present for the
remainder of a structure’s design life. It
should be understood that the cracking
in reinforced concrete member is
not a defect; EN 1992-1-1, Cl. 7.3.1
states that: “Cracking is normal in
reinforced concrete structures subject
to bending, shear, torsion or tension
resulting from either direct loading
or restraint to imposed deformation”.
However problems may arise when
crack occurs of width that affects the
durability of the structure to render it
unserviceable. Because cracks affect
the serviceability of a structure, the
limit state of excessive crack width
needs to be considered in design.
In situations when bending is the main
action effect, flexural cracks will form.
These cracks appear at the tension
face.
Flexure-Shear cracks form in regions
adjacent to the flexural cracks where
the shear force is more significant.
The flexural shear cracks initiates
from short vertical flexural cracks, but
become inclined. The cracking occurs
when a member under loading tends to
cause flexure. Shrinkage of concrete
or temperature changes may cause the
occurrence of restrained deformation.
These actions can cause significant
flexural or direct tensile stresses in the
member. Without steel reinforcement, a
cracked section cannot provide flexural
or tensile restraint to the adjoining
concrete segments in a member, and
crack control is impossible. Sufficient
amount of reinforcing steel is required
in RCC member to control cracking
under these circumstances. The way
in which tension reinforcement can
control cracking in a RCC member
subjected to restrained deformation
arising from concrete shrinkage is
illustrated in Fig. 1.
Fig. 1 Control of Cracking Caused by Restrained Deformation[1]
While using high grade reinforcing
steel (i.e. 500 MPa), this allows the
increase in the design yield stress of
the steel and in turn will allows to
reduce the area of steel required at
the strength limit state. Reducing the
amount of steel in a reinforce-concrete
member, even if it is of higher yield
strength, will generally increase the
possibility of serviceability problems
such as cracking.
It is of prime importance for designer
to understand the effect that bar
spacing and bar diameter can have on
the maximum allowable steel stress,
while still keeping crack widths to an
acceptable level.
2
CRACK WIDTH LIMITS
As a rule, a designer should aim to
detail a flexural member such that
tensile strains are distributed over a
large number of narrow cracks rather
than a small number of wide cracks
in the surface of the concrete. (Refer
Fig. 1).
* Joint Principal Consultant, Spectrum Techno Consultants P. Ltd, E-mail: [email protected]
19
TECHNICAL PAPERS
ii)
Simplified rules derived directly
from the crack width formulae
provide acceptable values of bar
dia. and bar spacing depending
on the maximum stress in the
steel under service loads.
While designing for flexural cracking
in member, estimates of the bending
moments for the serviceability limit
state need to be calculated at critical
sections.
The control of surface cracking is
particularly important in following
situations:
-
Where surface will be visible, as
excessive crack widths can give
an overall impression of poor
quality.
-
Can limit the types of floor coverings that can be successfully
used.
Crack control is also important for
durability where the cracks would
provide pathways for the ingress of
corrosive substances such as water
into reinforcement.
The design rules contained in
IRC:112-2011 for flexural elements
are intended to control the width of
both of these types of cracks.
IRC:112 allows a tiered approach to
design :
i) Crack width formulae can
be used to keep crack widths
below the design crack width
(refer Table 12.1)
The fundamental principles behind the
design approach adopted in IRC:112
are as follows:
i) A minimum amount of bonded
reinforcement is required.
ii) Yielding of the reinforcement
must not occur during crack
formation.
iii) Crack control is achieved by
limiting stress in reinforcement
or bar spacing and/or bar
diameter.
Table 1 Recommended Values of wmax
(Ref : IRC:112-2011 Table 12.2)
Condition of Exposure as
per Cl. 14.3.1
RCC & PSC Members
with Un-Bonded Tendons
PSC Members with
Bonded Tendons
Quasi-permanent load
combination
Frequent load combination
mm
mm
Moderate
0.3
0.2
Severe
0.3
0.2
Very Severe and Extreme
0.2
0.2 and decompression
3
CLASSICAL THEORY
to develop, and slip between the steel
and concrete remains zero.
The first crack forms at the weakest
section somewhere in the region
of uniform strain when the tensile
strength of the concrete is reached.
This assumes that the tensile
capacity of the bar exceeds that of the
concrete.
The force in the steel bar equals the
applied load, while the concrete is
unstressed at the crack faces. Also,
slip occurs and bond stress, τ occurs
between the concrete and the steel
bar over a transfer length, ltr, each
side of the crack. It is by bond that
stress is transferred into the concrete.
Depending on the overall length
of the element in the relation to the
transfer length, other cracks can form
at slightly higher loads.
Theoretically, the spacing between
cracks that form adjacent to each other
cannot be less than ltr, and cannot
exceed 2ltr.
Scr,min = ltr
Scr,max = 2ltr
Finally, crack width equals the
elongation of the steel between two
adjacent cracks less the elongation of
the concrete, and can be written as
below.
wk = Scr,max (εsm – εcm)
wk is the design crack width
εsm & εcm are the mean steel and concrete
stains over the transition length ltr.
4MINIMUM REINFORCEMENT
(Cl. 12.3.3, IRC:112-2011)
Fig. 2 Cracking in Tension[1]
Consider the behaviour of a reinforced
concrete tension element with a
longitudinal reinforcing bar placed
concentrically in its cross-section and
loaded at each end by a known force.
20
When the bar is loaded in tension,
some bond breakdown occurs
between the bar and the concrete near
the ends of the element. Further, a
uniform strain distribution is assumed
IRC:112 requires that a minimum
area of bonded reinforcement must be
provided in beams and slabs subjected
to restrained deformation where a
state of tension is induced. The
steel must not yield while the
cracks develop. If the steel yields,
deformation
will
become
concentrated at the crack where
yielding is occurring, and this will
inevitably invalidate the formulae.
TECHNICAL PAPERS
The equation for calculating this
minimum area has been derived
assuming equilibrium between the
tensile forces in the steel and the
concrete.
Eq... 12.1,
IRC:112-2011
the minimum area of
reinforcing steel within the
tensile zone.
kc = is a coefficient which
takes account of the stress
distribution within the
section just prior to
cracking and of the change
of the lever arm:
For Pure Tension kc = 1.0
For bending or bending combined with
axial forces:
-
For rectangular sections and webs
of box sections and T-sections:
As,min=
-
Eq... 12.2,
IRC:112-2011
For flanges of box sections and
T-sections:
Eq... 12.3,
IRC:112-2011
k = is the co-efficient which allows
for the effect of non-uniform
self-equilibrating stresses, which
lead to a reduction of restraint
forces.
= 1.0 for webs with h < 300 mm
or flanges with widths less than
300 mm
= 0.65 for webs with h > 800 mm
or flanges with widths greater
than 800 mm
Intermediate
values
may
be
interpolated.
fct.eff = is the mean value of the tensile
strength of the concrete effective
at the time when the cracks may
first be expected to occur.
=
fctm or lower, (fctm(t)), if cracking
is expected earlier than 28 days.
In
calculating
the
minimum
reinforcement to cater for shrinkage
fct,eff should be taken as the greater of
2.9 MPa or fctm(t).
Act =The area of concrete within
tensile zone. The tensile zone
should be taken as that part of the
concrete section which is
calculated to be in tension just
before the formation of the first
crack.
σc = is the mean stress of the concrete
acting on the part of the section
under consideration:
k1 = is a co-efficient considering the
effects of axial forces on the stress
distribution:
= 1.5
if NED is a compressive
force
= 2h*/(3h) if NED is a tensile force
h*
=
h
for h
<
1.0 m
=
1.0 m for h
≥
1.0 m
Fcr = is the absolute value of the tensile
force within the flange just prior
to cracking due to the cracking
moment calculated with fct,eff
5
CALCULATION OF CRACK
WIDTH
(Cl. 12.3.4, IRC:112-2011)
wk = Scr,max (εsm – εcm)
where,
wk = the characteristic crack width
sr.max = the maximum crack spacing
NED = is the axial force at the serviceability limit state acting on the
part of the cross-section under
consideration (compressive force
positive).
NED should be determined under
the relevant combination of actions
considering
the
characteristic
value of prestress and axial forces.
εsm = the mean strain of the reinforcement in the length sr,max under the
relevant combination of loads,
including the effect of imposed
deformations and taking into
account the effects of tension
stiffening.
εcm = the mean strain in the concrete
in the length sr,max between
cracks.
Fig. 3 RCC Rectangular Section
21
TECHNICAL PAPERS
Calculation of sr,max :
a)
where bonded reinforcement is
fixed at reasonably close centres
within the tension zone,
spacing ≤ 5( c + φ/2)
or
where there is no bonded reinforcement
within the tension zone.
Sr.max = 1.3(h – x)
h = effective depth
x = depth of neutral axis from the
compression zone.
Depth of Neutral Axis :
c = the cover to the longitudinal
reinforcement
k1 = a co-efficient which takes
account of the bond properties of
the bonded reinforcement.
=
0.8 for high bond bars
=
1.6 for bars with an effectively
plain surface (e.g. Prestressing
Tendons)
The second moment of area of the
cracked section, in steel units, is
derived from the cross section shown
in Fig. 4 below.
0.5 for bending
=
1.0 for pure tension
For the cases of eccentric tension or
for local areas, intermediate values
of k2 should be used which may be
calculated from the relation:
where, ε1 is the greater and ε2 is the
lesser tensile strain at the boundaries
of the section considered, assessed on
the basis of the cracked section.
For deformed bar associated with pure
bending:
CONTROL
OF
CRACKING
WITHOUT DIRECT CALCULATION
To simplify the calculations of
controlling the crack width, the
rules given in section 12.3.4 of
IRC:112-2011 may be presented in
tabular form by restricting the bar
diameter or spacing.
Table 12.2 of IRC:112-2011 gives
maximum bar diameter subjected to
different stress levels of steel under
relevant combination of load for which
crack width is to be controlled.
Table 12.2 Maximum Bar Diameter
φs for Crack Control
Steel Stress
(MPa)
k2 = a coefficient which takes account
of the distribution of strain:
=
6
(Cl. 12.3.6, IRC:112-2011)
Eq... 12.8,
IRC:112-2011
where,
The above may also be applied to
flanged beams where either the neutral
axis remains in the compression flange
(when ‘b’ is the flange width, or
remains in the web when the flange is
wholly in tension (where upon ‘b’ is
the web width).
Fig. 4
The Elastic Section modulus are:
Concrete : zc = I/dc
Steel : zs = I/(d - dc)
For a given Moment MED,
The Stresses are :
Concrete :
Steel :
wk = 0.2
mm
160
32
25
200
25
16
240
16
12
280
12
-
320
10
-
Table 12.3 of IRC:112-2011 gives
maximum spacing of bars.
The parameters assumed for the values
in those tables are:
c = 40 mm, fct,eff = 2.8 MPa, hcr = 0.5,
(h-d) = 0.1h, k1 = 0.8, k2 = 0.5 and
k = 1.0
Table 12.3 Maximum Bar Spacing for
for Crack Control
Steel Stress
(MPa)
The Strains are :
b)
22
Eq... 12.11,
IRC:112-2011
where spacing of the bonded
reinforcement exceeds 5( c + φ/2)
Concrete :
Steel :
Max. Bar Size (mm)
wk = 0.3
mm
Max. Bar Spacing (mm)
wk = 0.3 mm wk = 0.2 mm
160
300
200
200
250
150
240
200
100
280
150
50
320
100
-
TECHNICAL PAPERS
Fig. 5 Bar Diameter as a Function of Maximum Steel Stress
(Table 12.2, IRC:112-2011)
Max Steel Stress
7
=
=
Fig. 6 Maximum Steel Stress as a Function of Bar Spacing
(Table 12.3, IRC:112-2011)
(500 - Bar Spacing)/1.25
(400 - Bar Spacing)/1.25
for wk = 0.3 mm
for wk = 0.2 mm
NUMERICAL EXAMPLE
7.1 Crack Width Calculation As Per Irc:112-2011
23
TECHNICAL PAPERS
24
TECHNICAL PAPERS
7.2 Control of Cracking without Direct Calculation as per Irc:112-2011
25
TECHNICAL PAPERS
26
TECHNICAL PAPERS
8
CONCLUSION
The design provisions for the crack
width given in IRC:112-2011 are
more elaborate and needs to be well
understand in order to design more
serviceable structures. The content of
this paper will help to understand the
basic theory and procedure to design the
serviceability limit state of crack with as
per requirements laid in IRC:112-2011
with direct calculation or without direct
calculations.
Design, Published by Centre for
Construction Technology Research,
Uni. of Western Sydney (August 2000).
2.
Code of Practice for Concrete Bridges
IRC:112-2011.
3.
Designers Guide to EN-1992-2,
Part 2: Concrete Bridges by C.R. Hendy
and D.A. Smith.
REFERENCES
1.
One Steel Reinforcing Guide to
Reinforced Concrete Design: Crack
Control of Slabs: Part 1: AS 3600
27
A Study on Porous Concrete Mixes for Rigid Pavements
A.U. Ravi Shankar* and Nitendra Palankar**
ABSTRACT
The prime objective of this research is to investigate the effect of variation of sand and cement content on the porous concrete
properties. Four aggregate gradations are selected by varying the percentage of sand (by volume) in total aggregate. Eleven types of
mixes are used by varying the cement content for these four aggregate gradations. Dry unit weight, porosity, compressive strength,
flexural strength, coefficient of permeability, clogging and abrasion resistance of the porous concrete are tested. The relationships
among the engineering properties of the porous concrete are also discussed. With the increase of sand and cement content in porous
concrete mixes the compressive strength, flexural strength and dry unit weight increases where as the porosity and coefficient of
permeability decreases. The study indicates that clogging of porous concrete mixes resulted in the reduction of permeability. Abrasion
values obtained from the tests are less than the specified values for heavy duty floor tiles.
1
Introduction
Porous concrete is generally described
as an open-graded material with zero
slump value and is composed of
Ordinary Portland Cement (OPC),
single sized coarse aggregates, little
or no fine aggregates, admixtures and
water. Such a hardened composite
consists of interconnected pores of size
in the range 2 - 8 mm which facilitates
the water to pass through it. The void
content of porous concrete may vary
between 18% to 35% and may achieve
compressive strengths in the range
2.8 to 28 N/mm2 (ACI 522R 2006).
The use of porous concrete in
pavements is associated with certain
advantages such as reduction of the
volume of direct water runoff from
pavements and enhancement of
quality of storm water. Several
other advantages of porous concrete
include reduction in the noise,
hydroplaning, improvement of skid
resistance, preservation of ecosystem, minimisation of heat island
effect in large cities etc (Tennis et al.
2004). However, the porous concrete
has several disadvantages such as
frequent maintenance in order to
remove the clogged material in the
voids to restore the permeability and
also possible contamination of ground
water depending on soil conditions
(Wang et al. 2006). One of the main
drawbacks of porous concrete is the
low strength and durability properties
which limit use of porous concrete
in normal roadways. According
to Tennis et al. (2004), the typical
compressive strength of porous may
be in the range 3.5 to 28 N/mm2 with
an average value of 17 N/mm2. With
proper proportioning and compaction,
compressive strength greater than
20 N/mm2 may be achieved (Ghafoori
and Dutta. 1995).
The present study is carried out to
determine the effect of variation
of sand and cement content on the
porosity,
permeability,
abrasion
resistance, effect of clogging and
strength of porous concrete mixes.
The relationships between porosity,
permeability, and strength in porous
concrete mixes are also discussed.
Since the concrete pavements are
designed for a long service life,
the durability properties of porous
concrete need to be considered to
ensure long term performance. Very
few research works on the durability
properties of porous concrete have
been investigated till date. The
clogging of the pores is another
problem associated with porous
concrete. The functionality of the
porous concrete is lowered due
to the clogging of dirt and debris
particles which fill the pore network.
The permeability of the concrete is
severely affected due to clogging.
However, studies conducted by Tennis
et al. (2004) have indicated that
the porosity of the clogged porous
concrete can be restored with use
of pressure washing nearly to new
conditions. The main objective of
the study is to evaluate and improve
the strength of porous concrete by
varying sand and cement content.
2.1Materials
Ordinary Portland Cement (OPC)
43 grade tested as per IS:8112-1989
specification was used in the present
investigation. The OPC with a fineness
0010 m2/kg and specific gravity of
3.11 achieved a compressive strength
of 48.54 MPa when tested.
Single-sized crushed granite coarse
aggregate of maximum size 12 mm
from locally available quarries and
locally available river sand fine
aggregate were used in this study.
Coarse aggregate and fine aggregates
were tested as per the relevant IS
specification IS:2386 (part III, IV)1963 and the results are tabulated in
Table 1. The sieve analysis results
of coarse and fine aggregates are
tabulated along with the requirement
of IS codes (IS:383-1970) in Table 2.
The Conplast SP430 super-plasticizers
was used to obtain good workability
due to low water-cement ratios of
mixes.
2Experimental Investigation
* Professor, E-mail: [email protected], ** Research Scholar, E-mail: [email protected], Dept. of Civil Engineering,
National Institute of Technology, Surathkal, Srinivasnagar, Karnataka
28
TECHNICAL PAPERS
Table 1 Properties of Coarse Aggregate
S. No.
Test
1
Specific Gravity
2
Bulk Density
a) Dry loose
b) Dry rodded
Coarse Aggregates
Fine aggregates
2.68
2.61
1416kg/m3
1548 kg/m3
1435 kg/m3
1706 kg/m3
3
Water absorption, %
0.5
0.8
4
Aggregate crushing value, %
27.6
-
5
Los angeles abrasion value, %
21.3
-
6
Aggregate impact value, %
28.1
-
Table 2 Sieve Analysis of Fine Aggregate
IS Sieve
Size
Percentage
Passing (%)
12.5
100
Grading for
Zone III
Percentage
Passing (%)
Fine Agregates
P=
Grading for Single Sized Aggregate of
Nominal Size 10 mm
Coarse Aggregates
100
100
100
10 mm
100
100
87.6
85-100
4.75 mm
100
90-100
1.9
0-20
2.36 mm
98.7
85-100
0.4
0-5
1.18 mm
91.5
75-100
-
-
600 µ
66.5
60-79
-
-
300 µ
7.6
12-40
-
-
150 µ
1.4
0-10
-
-
2.2Mix Design
Table 3 Details of Mix Proportions
Mix
Cement
(kg/m3)
Coarse Aggregate
(kg/m3)
Sand
(kg/m3)
Water
(kg/m3)
Super Plasticizer
(kg/m3)
% of Sand by Volume of
Total Aggregate
A
250
1524
165
87.5
2.50
10
B
275
1483
160
96.2
2.75
10
C
300
1443
156
105.0
3.00
10
D
250
1439
247
87.5
2.50
15
E
275
1401
241
96.2
2.75
15
F
300
1362
234
105.0
3.00
15
G
250
1355
330
87.5
2.50
20
H
275
1318
321
96.2
2.75
20
I
300
1283
312
105.0
3.00
20
J
250
1270
412
87.5
2.50
25
K
275
1236
401
96.2
2.75
25
[1 − (
WD − WS
ρw VT
)]100 ... (1)
Where, P = porosity of specimen
(%); WD = dry mass of specimen (g);
Ws = submerged mass of specimen (g);
VT = total volume of specimen (cm3);
ρw = density of water (g/cm3).
of (100x100x500) mm were cast and
tested to determine the flexural strength.
The cylindrical specimens of 100 mm
in diameter and 200 mm in height were
cast and tested for permeability and
clogging. The specimens of size
(70x70x25) mm thick were cast for
abrasion resistance test. Cube specimens
were prepared by tamping 25 times
with tamping rod in three layers as per
IS:516-1959. Cylinders were prepared
by tamping 30 times with tamping rod
in four layers. Beams were prepared
by tamping 25 times with square
plate in three layers. All the samples
were subsequently de-moulded after
24 hours and placed in water tank
for curing.
The concrete mix design is based
on the guidelines recommended by
IS:10262:2009. Four fine aggregate
gradations were used by varying
percentage of sand by volume in total
aggregate at 10% 15%, 20% and 25%.
Eleven types of mixes were used by
varying the cement content for these
four aggregate gradations, keeping
constant water-cement ratio of 0.35.
The concrete mix proportions used
are summarized in Table 3. In order
to evaluate various properties of
porous
concrete
mixes,
cube
specimens of size 100 mm were
tested for compressive strength, dry
density and porosity. Beam specimens
2.3 Porosity
The porosity of porous concrete
was determined by calculating the
difference in weight between the dry
samples and submerged under water
sample for cube specimens of size
100 mm and using Eq.1 (Montes et al.
2005).
2.4 Permeability
The falling head permeability setup
was
used
to
determine
the
permeability of the porous concrete
mixes. A specimen of length 100 mm
was prepared by cutting the top and
bottom sections of cylinder of size
200 mm length x l00 mm diameter.
The circumferential sides of the
specimen were coated with thin layer
of paraffin wax in order to avoid
leakage of water through the sides
of the specimen. Paraffin wax was
carefully applied on the specimen
preventing the clogging of voids with
wax in the specimen. When the water
is allowed to drain out of the sample,
time required for the water level to fall
from one level to another level in the
calibrated tube was noted down. Three
different water levels were selected
and for each water level six readings
were recorded. The coefficient of
permeability (k) was determined using
Eq.2 for each reading. The average
value at different water heights
was determined as coefficient of
permeability of sample.
k=
 h1 
aL
log e    h2 
At
 
... 2
29
TECHNICAL PAPERS
Where, k = coefficient of permeability
(cm/s); a = cross sectional area
of standpipe (cm2); L = length of
specimen (em); A = cross sectional
area of specimen (cm2); t = time in
seconds from hi to h2; hi = initial water
level (cm); h2 = finial water level
(cm).
2.5 Clogging Test
The clogging test was conducted
after the permeability of concrete
samples were measured. The degree of
clogging was evaluated by measuring
the change in permeability due to
addition of clogging material to
porous concrete. Eight different
porous concrete mixes (A, B, C, D, E,
F, G and H) were investigated in this
study. The test procedure proposed
by Joung et al. (2008) was adopted in
the present study with minor changes
related to specimen geometry and
method of application of clogging
material. Clogging fluid was prepared
by adding 30 g of fine clogging
material (sand) per 1 kg water in a
bucket. The clogging fluid was poured
into the collar of the test specimen
up to its brim, and was then allowed
to drain off completely to allow the
clogging material to settle in the pores.
The procedure was repeated 5 times
in order to ensure proper clogging
in porous concrete cylinder. Sand
clogged sample was set in fallinghead permeameter and time duration
for water level to fall from initial
level to final level while draining was
measured.
2.6 Abrasion Resistance Test
The abrasion test was conducted
according to the procedure suggested
in IS:1237-2012, which is used for
determination of abrasion resistance
of concrete flooring tiles. Eight
different porous concrete mixes (A, B,
C, D, E, F, G and H) were investigated
in this study. The specimens were
30
tested after 28 days of curing on
specimen of size (70x70x25) mm.
After the completion of test, the value
was checked up with average loss in
thickness of specimen obtained by
Eq.3. Fig. l shows experimental set-up
for abrasion resistance test.
t=
(M1 − M 2 )V1
M1 A
specimen (g); V1 = initial volume of
specimen (mm3); A= surface area of
specimen (mm2).
... (3)
Where, t = average loss in thickness
(mm); M1 = initial mass of specimen
(g); M2 = final mass of abraded
Fig. 1 Experimental Setup of Abrasion
Resistance Test
Table 4 Engineering Properties of Porous Concrete
Compressive Strength
(N/mm2)
Flexural Strength
(N/mm2)
Coefficient of
Permeability (cm/s)
Mix
Porosity
(%)
Dry Unit Weight
(kN/m3)
7-day
28-day
28-day
A
22.23
18.93
6.5
10.1
1.64
B
19.70
19.64
8.0
12.6
1.93
0.1120
C
16.56
19.97
9.1
15.5
2.33
0.0818
D
19.50
19.80
7.5
12.4
2.14
0.1070
E
16.27
20.22
8.8
14.5
2.26
0.0853
0.2189
F
14.23
20.56
10.3
17.1
2.8
0.0264
G
13.87
20.20
10.1
16.5
2.56
0.0241
H
12.04
20.87
10.5
17.6
2.73
0.0218
I
11.87
21.36
12.6
20.8
3.18
0.0106
J
11.53
20.75
9.5
16.7
2.69
0.0105
K
10.88
21.06
11.1
18.2
2.93
0.0063
3Results and Discussions
3.1Engineering Properties of
Porous Concrete
The porous concrete test results are
shown in Table 4. Compressive
strength in porous concrete is in
general lower than conventional
concrete due to the high porosity. The
mix ‘I’ had the maximum compressive
strength of 20.83 N/mm2 and flexural
strength of 3.18 N/mm2 corresponding
to the porosity of 11.87%. The mix ‘A’
had the lowest compressive strength
of 10.17 N/mm2 and flexural strength
of 1.64 N/mm2 corresponding to the
highest porosity of 22.23%. The test
results indicate a range of permeability
values between 0.2189 cm/s and
0.0063 cm/s. While comparing
the 7-day and 28-day compressive
strength, the 28-day compressive
strength increases from 56% to
72% which is almost same as the
conventional concrete. As the
percentage of sand by volume in
total aggregate and cement content
increased the compressive strength,
flexural strength and dry unit weight
of porous concrete increased where
as the coefficient of permeability and
porosity decreased. The increase in
sand content in mixes led to increased
packing within the composite resulting
improvement in the strength of the
mixes. The increase in cement content
resulted in stronger bond between
the paste and the aggregates; thus
leading to higher strength. With
increase in sand content from 20% to
25% of total aggregate, no significant
TECHNICAL PAPERS
improvement in the strength is
noticed, however decrease in the
porosity and permeability is observed.
In case of porous concrete, the
interficail transistion zone between
paste and aggregate is relatively
weak and the concrete always fails
at interficail transition zone (Jing and
Guoliang, 2003). Further addition of
sand beyond an optimal limit may not
not have any influence on the strength
parameters as the concrete fails at
the interficail transition zone. The
decrease in porosity and permeability
at higher replacement by sand (25%)
may not be desirable as it would lower
the functional purpose of porous
concrete. The sand content of 20%
by volume of total aggregates may be
considered optimal content for present
study.
3.2Relationship Between Compressive Strength, Porosity and
Permeability
The compressive strength of porous
concrete decreased linearly as
porosity increased as shown in
Fig.2 for 28-day compressive
strength. As percentage of sand (by
volume) in total aggregate and cement
content increased, the compressive
strength of porous concrete increased
where as the porosity decreased.
From Fig. 2, it is evident that the
coefficient of permeability of porous
concrete mixes increase exponentially
with increase in porosity. The
permeability is increasing rapidly
for voids greater than 15%. The
coefficient of permeability ranges
from 0.0063 cm/s to 0.2189 cm/s
for all the mixes. From Fig. 2 it is
evident that permeability increases
as porosity increases and strength
decreases. Mixes with porosity
between 12% and 17% achieve
adequate 28-day compressive strength
of about 15 N/mm2 or more and a
permeability between 0.02 cm/s and
0.08 cm/s.
Fig. 2 Relationship between Porosity, Permeability and 28-Day Compressive Strength
3.3Effect of Clogging Materials on
Coefficient of Permeability
The effect of clogging on permeability
of concrete mixes was evaluated for
mixes with permeability more than
0.02 cm/s. Clogging tests confirmed
that most of clogging material will be
trapped on top of concrete, however,
a part of finer sand fraction will be
deposited within concrete, or travel
through the concrete. Denser, less
permeable surface acted like coarse
filter, passing small particles but
trapping larger ones. This phenomenon
will affect apparent permeability
of porous concrete by clogging the
surface or near-surface region. For
each cycle of clogging, 30g/1000g
(sand/water) was added for each
sample, but not all the 30g is fully
clogged in sample. The amount
of clogged sand inside the sample
ranges from 2 to 20 g for each
cycle; the rest of the sand was
remaining on top of specimen or
flushed out. Table 5 shows variation
in permeability due to each cycle of
clog. The initial permeability was
found to vary between 0.2189 cm/s
(mix A) and 0.0218 cm/s (mix H).
Table 5 Variation in Permeability due to Each Cycle of Clog
Clogging
Cycle
0
Permeability Values at the End of Each Cycle of Clog for Each Mix Tested, cm/s
A
B
C
D
E
F
G
H
0.2189
0.1120
0.0818
0.1070
0.0853
0.0264
0.0241
0.0218
1
0.1852
0.0841
0.0612
0.0813
0.0651
0.0213
0.0194
0.0165
2
0.1482
0.0642
0.0426
0.0689
0.0523
0.0184
0.0152
0.0142
3
0.1256
0.0512
0.0354
0.0591
0.0436
0.0158
0.0126
0.0125
4
0.1093
0.0468
0.0289
0.0511
0.0385
0.0132
0.0113
0.0106
5
0.1019
0.0446
0.0254
0.0475
0.0359
0.0112
0.0096
0.0092
Fig. 3 depicts the relationship
between coefficient of permeability
and amount of clogging material
added to specimens. With addition
of clogging material in each cycle,
the coefficient of permeability
decreased, with the largest decrement
of permeability occurred after first
clogging cycle. From Fig. 3, it can be
noticed that percentage decrease in
permeability with clogging decreases
with increasing the sand content in
concrete. The largest decrease in
permeability at the end of five cycles
is observed in mix containing 10%
sand and cement content of
250 kg/m3. This may be due to higher
porosity in low sand content mixes
31
TECHNICAL PAPERS
which allow clogging materials
to accumulate in large pores thus
reducing the permeability drastically;
in comparison with mixes containing
high sand content with relatively
lower porosity and small sized
pores with reduced accumulation of
materials leading to relatively lower
reduction in permeability.
3.
sand content in the concrete. The
maximum decrease in permeability at the end of five cycles was
observed to be in mix containing
10% sand and cement content of
250 kg/m3.
Abrasion values obtained from
test are less than specified values for heavy duty floor tiles.
The abrasion resistance was unaffected by the sand content in
the mixes, however the higher
cement content slightly improved
the abrasion resistance.
References
1.
Fig. 3 Relationship between Coefficient of Permeability and
Amount of Clogging Material Added
3.4 Abrasion Resistance of Porous
Concrete
Table 6 presents the abrasion values
for different mixes of porous concrete.
The average loss in thickness
calculated as per Eq.6 was found
to be in the range 0.21 to 0.28 mm
for all the mixes. The effect of
variation of sand content did not
have any significant effect on the
abrasion resistance of porous concrete
2.
mixes. However, it was noticed
that the abrasion resistance slightly
improved with the higher cement
content in the mixes. All the values
are less than that specified in IS:12372012 i.e. for general purpose tiles,
average wear < 3.5 mm and wear on
individual specimen < 4 mm, while for
heavy duty floor tiles average wear < 2
mm and wear on individual specimen
< 2.5 mm.
3.
4.
Table 6 Abrasion Values for Different Mixes of Porous Concrete
Mix
A
B
C
D
E
F
G
H
Average loss in
thickness (mm)
0.28
0.23
0.22
0.26
0.22
0.21
0.26
0.21
4
Conclusions
The following conclusions are drawn
from the present investigation:
1. With the increase of sand and
cement content in porous
concrete mixes, the compressive
strength, flexural strength and dry
unit weight increased, however
the coefficient of permeability
and porosity decreased. Overall,
results of all concrete mixes
indicate
that
mixes
with
porosity between 12% and 17%
achieve adequate compressive
strength (≥ 15 N/mm2) and
32
2.
permeability between 0.02 cm/s
and 0.08 cm/s.
The
studies
showed
that
clogging of porous concrete
mixes resulted in reduction in
permeability. Initial values of
0.2189 cm/s (mix A) and 0.0218
cm/s (mix H) were reduced to
0.1019 cm/s and 0.0092 cm/s
respectively after clogging. The
clogged permeability values
decreased between 53.5% and
69%. The percentage decrease in
the permeability with clogging
decreases with increasing the
5.
6.
7.
ACI Committee 522 (2006), “Pervious Concrete”, 522R-06, American
Concrete Institute, Farmington Hills,
Michigan, pp 1- 25.
Ghafoori N. and Dutta S. (1995),
“Laboratory
Investigation
of
Compacted No-Fines Concrete for
Paving Materials”, Journal of
Materials in Civil Engineering.
Vol. 7, No.3, pp 183-191.
Jing Y. and Guoliang J. (2003),
“Experimental Study on Properties
of Pervious Concrete Materials”,
Cement and Concrete Research,
Vol. 33, pp 381-386.
Joung Y. and Grasley Z.C. (2008),
“Evaluation and Optimization of
Durable Pervious Concrete for use
in Urban Areas”, Research Report
SWUTC/08/167163-1.
Montes F., Valavala S., and Haselbach
L.M. (2005), “A New Test Method for
Porosity Measurements of Portland
Cement Pervious Concrete”, Journal
of ASTM International, Vol.2. No.1.
pp 1-13.
Tennis P.O., Leming M.L. and
Akers D.J. (2004), “Pervious
Concrete
Pavements”,
Special
Publication by Portland Cement
Association and National Ready
Mixed Concrete Association.
Wang K., Schaefer V.R., Kevern
J.T. and Suleiman, M.T. (2006),
“Development of Mix Proportion
for Functional and Durable Pervious
Concrete”, Submitted to Concrete
Technology
Forum-Focus
on
Pervious Concrete, National Ready
Mix Concrete Association, Nashville,
TN, pp 23-25.
33
34
35
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