International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 08 Issue: 09 | Sep 2021 www.irjet.net p-ISSN: 2395-0072
© 2021, IRJET | Impact Factor value: 7.529 | ISO 9001:2008 Certified Journal | Page 1546
Study on Anti-Stripping Performance of Lime in Bituminous Mix
Venkatesh Baskaran
1
, Ga Theerumalai
2
, S. Mohamed Mustafa
3
1
Assistant Professor, Dept. of Civil Engineering, Government College of Engineering, Tirunelveli, India
2
Dept. of Civil Engineering, Government College of Engineering, Tirunelveli, India
3
Dept. of Civil Engineering, Government College of Engineering, Tirunelveli, India
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Abstract - Road infrastructure is generally considered an
indicator of the economic development of any country. India
was and still is a country where the majority of major roads
are made of asphalt. During its service period, the flexible
pavement exhibits various defects. Aggregates being stripped
off bituminous roads are a typical problem in our country.
Recent studies demonstrate that lime acts as an anti-oxidant,
active filler, and additive to bituminous mix. Hydrated lime's
effectiveness in asphalt mixtures is due to the strong
interactions between the principal components, aggregate,
and bitumen. The hydrated lime reacts chemically with the
acids in the bitumen and improving the mixture's moisture
resistance. In this study, lime was mixed using the slurry
method since it is quite easy to do in our laboratory, whereas
two other dry injection mixers and dry lime can only be made
in asphalt mixers on the damp aggregate. The experimental
test on stripping value of aggregate before and after mixing
the lime was done as per IS.: 6241-1971. The optimal lime
proportion was determined as 3% of the total weight of
aggregate. The investigation concluded that the bituminous
mix with lime reduces the stripping value. The pavement laid
using these bituminous mixes would not strip from any portion
of flexible pavement. This mixture may avoid faults like
rutting, cracking, edge drops, and so on.
Key Words: Hydrated lime, Stripping value, Slurry
method, Bituminous mix, Moisture resistance, Flexible
pavement
1. INTRODUCTION
Transportation infrastructure investments have a critical but
indirect role in the development process. To raise the overall
standard of living and eradicate poverty, India must
sustainably continue its growth momentum. In this sense,
infrastructure is crucial as it is strongly linked to economic
growth and poverty reduction [1]. Regions with poor
transportation infrastructure typically have lower per capita
income, a higher concentration of primary industry, and a
lower population density[2].
Flexible pavements are preferred over rigid concrete
roadways due to several advantages, including the ability to
be strengthened and upgraded in stages as traffic increases.
Flexible pavements are the least expensive in terms of both
initial and maintenance costs [3].
Extensive road networks created at significant expense in
India have been poorly maintained and used far more than
their design values. Apart from insufficient capacity and
pavement thickness, the main flaws in our highway system
are poor ride quality, deteriorated and distressed
bridges/culverts, congested stretches, and excessive axle
loading. However, water infiltration can damage a pavement
structure in a single season[4].
Bitumen properties such as acid number, molecular size
distribution, and penetration grade had no effect on
moisture sensitivity in a bituminous mix. Regardless of the
bitumen employed, mixtures containing alkali metals
(sodium and potassium) displayed rather high moisture
sensitivity. The variation in moisture sensitivity is due to
aggregate rather than bitumen[5].
Calcium-containing inorganic compounds with predominant
carbonates, oxides, and hydroxides are generally known as
lime. Calcium hydroxide is typically a white finely split
powder with a diameter of less than 0.15 mm. This paper
describes the most important benefits of adding lime to the
bituminous mix. This mixed lime was expected to act as an
anti-stripping agent[6]. The significant interactions between
the principal components, i.e., aggregate and bitumen, and
the combination of four effects, two each on the aggregate
and bitumen, explain why hydrated lime is particularly
successful in asphalt mixtures [7]. Hydrated lime alters
aggregate surface properties, enabling a surface composition
(calcium ions) and roughness (precipitates) that is more
conducive to bitumen adherence.
The existing clayey particles adhering to the aggregate
surface can be treated with hydrated lime, reducing their
adverse influence on the mixture. In addition, hydrated lime
reacts chemically with the acids in bitumen, slowing the age-
hardening kinetics and neutralizing the influence of the
"bad" adhesion boosters previously present in the bitumen,
improving the mixture's moisture resistance[8].
The study was conducted to examine if hydrated lime could
be employed as an anti-stripping agent in aggregate mixes
for use in road pavements after being mixed with aggregates
and bitumen.