STUDY THE EFFECT OF TIRE SHREDS ON THE STRENGTH OF
CEMENT/LIME STABILIZED SOIL
Abstract
Disposal of waste tires are becoming global problem. Therefore reuse them as a soil stabilizing agent is
an effective solution. In this study, effect of tire shreds on the strength of cement or lime stabilized soil
was investigated. Main intention was to identify best composite material among soil-cement, soil-lime,
soil-cement-tire shreds and soil-lime-tire shreds while obtaining contribution of tire shreds towards the
increment of soil strength. Initially cement and lime was added with soil by pre determined quantities to
stabilize the soil sample. A series of Modified Proctor Compaction tests and California Bearing Ratio
(CBR) tests was carried out on specimens. The strength of samples was determined by conducting both
soaked and un-soaked CBR tests. Optimum lime and cement percentages required to stabilize the soil
sample was determined separately. Tire shreds were added to cement stabilized and lime stabilized soil
samples separately and variation of strength was measured. Addition of 15% cement under soaked and
unsoaked condition gives maximum strength to the soil. Addition of 4% lime under soaked condition and
6% lime under unsoaked condition gives maximum strength to the soil. Addition of tire shreds does not
have a greater influence towards the strength increment of stabilized soil samples under soaked condition.
Addition of 1% tire shreds to the raw soil under unsoaked condition gives strength increment. Soil-lime
combination is the most economical composite material. Although soil-cement composite material is
costly, it gives the higher strength to the soil samples.
Introduction
Soil improvement techniques may be categorized as mechanical modification, hydraulic modification,
physical and chemical modification, and modification by means of inclusions and confinement.
(Promputthangkoon & Karnchanachetanee, 2013). The strength of soil can be improved by providing
additional artificial cementation to the soil using admixtures. In our study, cement and lime were used for
soil stabilizing.
Direct disposal of waste tires have been a global problem. According to the National Science Foundation
Sri Lanka, waste tires are accumulating in dumps at the rate of about 190 million per year, adding to the
existing inventory of 2 billion to 3 billion. Therefore it is an effective solution to use waste tire shreds as
soil stabilizing agent. In our research, typical tire shreds were added with both cement and lime stabilized
soil separately in order to check soil strength. Although lime and cement improve the strength of soil, our
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intention was to find the contribution of tire shreds towards the strength of stabilized soil samples.
Material & Methods
Soil samples were collected from a road construction site at Pilimathalawa- Poththapitiya Road. The
physical properties of soil are as follows.
Liquid Limit
= 67.60%
Plastic Limit
= 33.77%
Plasticity Index
= 33.83 %
Average specific gravity
= 2.68
British Soil Classification
=MH (High Plasticity Silt)
Atterberg limits Test was carried out according to BS 1377: Part 02. Specific Gravity of soil was
determined using Small pyknometer method. To identify the particle size distribution, wet sieving &
hydrometer test were done according to BS 1377: Part 02. The type of particle distribution was obtained
as well graded soil. Optimum moisture content and maximum dry density of soil samples were
determined by conducting Modified Proctor Compaction Test according to BS 1377: Part 04.
Optimum moisture content
= 11%
Maximum dry density
= 2010 kg/m3
To find the strength of stabilized soil samples, soaked and unsoaked CBR Tests were conducted
according to British Standards BS 1377: Part 04. Samples were soaked 96 hours for Soaked CBR Tests.
Soil stabilization was done at the optimum moisture content of raw soil. The quantity of stabilization
agent was varied according to pre defined percentages by weight. The quantity of stabilization agent
which gives highest CBR value at soaked condition and unsoaked condition was determined separately.
These optimum values were used to stabilize soil samples using tire shreds.
In order to stabilize soil using lime, quick lime powder was added. Quantity of lime added was varied as
2%, 4%, 6%, and 8 %.( By Weight). To stabilize the soil using cement, Ordinary Portland cement was
used. Quantity of lime added was varied as 5%, 10%, 15% and 20 %.( By Weight). To stabilize the soil
using tire shreds, 10mm x 20mm rectangular tire shreds with 2mm thickness were prepared using waste
tubes of bicycle tires. Quantity of tire shreds added was varied as 1%, 3% and 5 %( By Weight) to
stabilize raw soil, lime stabilized soil and cement stabilize soil separately under soaked and unsoaked
conditions. It was assumed that no water absorption happened by the tire shreds.
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Results and discussion
Soil Stabilization using Lime
Maximum CBR Value obtained,
For Soaked CBR test
- at 4 % Lime quantity by weight
For Unsoaked CBR test
- at 6 % Lime quantity by weight
Soil Stabilization using Cement
Maximum CBR Value obtained for unsoaked CBR tests was 15 % cement quantity by weight. CBR value
of soaked cement samples was continuously increased due to the increment of cement quantity. To add
tire shreds, 15% cement quantity was selected to stabilize soil under soaked and unsoaked conditions.
CBR Value
Soil Stabilization using Tire Shreds
250
CBR values for Soaked
Lime Samples
200
CBR values for
Unsoaked Lime
Samples
CBR values for Soaked
Cement Samples
150
CBR values for
Unsoaked Cement
Samples
CBR Values for Soaked
Raw Soil Samples
100
50
0
0
1
2
3
4
5
CBR Values for
Unsoaked Raw Soil
Samples
Tire Shred %
Fig 1: Variation of CBR Value with Tire shred Percentage
According to the above results, for raw soil samples and lime stabilized soil samples it gives maximum
CBR value at 1% Tire Shred addition under unsoaked condition. For cement stabilized soil samples it
reduced CBR value of soil samples continuously due to the addition of tire shreds. For raw soil, lime
stabilized soil and cement stabilized soil samples under soaked conditions, it continuously reduced initial
CBR value due to tire shreds addition.
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Conclusions
1. The addition of ordinary Portland cement(5%,10%,15% and 20% by weight) to the raw soil sample,
increases the initial soil strength from 65%-80% under unsoaked condition and increases the initial soil
strength from 370% - 660% under soaked condition.
2. The addition of lime (2%, 4%, 6% and 8% by weight) to the raw soil sample, increases the initial soil
strength from 40%-50% under unsoaked condition and increases the initial soil strength from 70% 135% under soaked condition.
3. The addition of 1% tire shreds by weight (10mm x 20mm x 2mm size) to the raw soil sample increases
the initial soil strength by 11.4% under unsoaked condition.
4. The addition of 1% tire shreds by weight to the lime stabilized soil sample increases the initial soil
strength by 1.6% under unsoaked conditions.
References
Ahmed, B., Alim, A., & Sayeed, A. (2013). Improvement of soil strength using cement and lime
admixtures. Earth Science, Vol. 2,No. 6 , 139-144.
Ayothiraman, R., & Meena, A. (2011). Improvement Of Sub grade Soil With Shredded Waste Tire
Chips. Indian Geotechnical Conference, Kochi (Paper No. H- 033) , 365-368.
British Standard BS1377: Part 2 1990
British Standard BS1377: Part 4 1990
Niroumand, H., & Kassim, K. (2010). Comparison of Compressive Strength in Mud Bricks with Shred
Tires and Concrete Particles as Sustainable Materials. EJDE , 1151-1157.
Shahin, M., & Hong, L. (2010). Utilization of Shredded Rubber Tires for Cement-Stabilized Soft Clays.
Ground Improvement and Geo synthetics -Proceedings of the GeoShanghai International Conference ,
181-186.
Singh, B., & Vinot, V. (2011). Influence of Waste Tire Chips on Strength . Journal of Civil Engineering
and Architecture , 819-827.
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