Highway Research Record No. 39 - Indian Roads Congress

5. Development of Improved Materials, Mixes
and Design Methods Achieving Reduced
Pavement Thickness
Date of Start : 01/01/2012
Date of Completion (Targeted) : 31/12/2015
CSIR-Central Road Research Institute, New
Delhi – 110 025 (R)
Scope and Objectives
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Improvement of available materials and mixes for
various layers of pavements
Determination of mechanistic properties of modified
materials and mixes
Development of new design templates for reduced
thickness
Validation of new designs by APTF evaluation
Methodology
Firstly various laboratory testing such as fatigue test,
resilient modulus, static creep etc, will be done to see the
improvement in the mechanistic properties of modified
materials and mixes for various layers of pavements.
Based upon above laboratory test results mechanistic
analysis will be performed to check the scope for
reduction of thickness based upon critical strains value.
Finally validation of proposed new structure will be
done with the help of APTF facility and producing the
results in the form of new design templates.
Interim Conclusions/Conclusions/Supporting Data
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Polymer modified binder improve the tensile
strength of the bituminous mix under dry and moist
conditions. Modified mix also has higher retained
Marshall Stability and tensile strength ratio, which
indicates improved resistance towards moisture
susceptibility.
The Creep Modulus of Modified mix indicates
improved rut resistance of modified pavement
at higher pavement temp. Utilization of modified
bitumen in bituminous layer reduces the permanent
deformation by 45 Per cent, 60.5 Per cent and
74.4 Per cent at 25, 35 and 45°C temperature.
The final rut achieved in slabs made with PMB
40 binder indicates lower rutting susceptibility of
modified mix as compared to unmodified mix made
with VG 30 binder.
The phase angle of unmodified mix is about
20 Per cent higher as that of modified mixture
which leads to more dissipation of energy during
flexural fatigue test and finally less resistance to
fatigue failure.
ROAD RESEARCH IN INDIA 2011-12 11
• Mechanistic
analysis revealed that cumulative
damage in fatigue will be less in modified pavement
as compared to unmodified pavement.
Reports/Publications
Effect of Elastomeric Polymer Modification on Fatigue
and Rutting Performance of Bituminous Pavement.
Further information/Copy of report can be obtained
from
Dr. P. K. Jain, Chief Scientist & Head, Flexible Pavement
Division, Central Road Research Institute, New Delhi –
110025, Mobile 9910113992, phone 011-26311117
Fax 011-26845943, e-mail ID: pramodj.crri@nic.in
6. Chrome Shavings as Stabilizing Additive and
Alternate Filler in Bituminous Mixes
Date of Start : July 2012
Date of Completion (Targeted): March 2017
I. Council of Scientific and Industrial Research
(CSIR), New Delhi (S)
II. CSIR- Central Road Research Institute,
New Delhi (R,I)
III. CSIR – Central Leather Research Institute,
Chennai (C,I)
Scope and Objectives
The scope and objective of the project focuses on the
utilization of tannery solid waste as an ingredient in the
formulation of road construction materials (road). The
main objective includes:
i. Collection of chrome shavings waste from
tanneries, and its processing.
ii. Preparation of modified bituminous mixes using
Chrome Shavings (CS).
iii. laying of experimental road sections to verify its
durability and long lasting characteristics.
Methodology
i. Collection of solid waste from various tanneries
and processing, Identification and quantum of
solid generated from various tanneries.
ii. Design of Mixes on:
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Chrome Shavings as Bitumen Modifier and
Alternate Filler in Bituminous Mixes
Design of Micro-surfacing mix
Design of perpetual pavement mixes like
Stone Matrix Asphalt (SMA) and Bituminous
Concrete (BC)