However, the shredded rubber and soil mixture, dependent on the amount of rubber content, is able to reduce the soil settlement and plastic pipe's diametral strain, attenuating the pipe's accumulating strains and, finally, protecting the buried pipe from fatigue under repeated loadings.
For the chipped rubber and soil mixture, the pipe has the highest strains under the cyclic loading irrespective of the amount of rubber in the soil.
This benefit is enhanced by the combined action of geocell reinforcement over rubber-modified soil.
Comparison of residual water content at high suction points (5000 15,000 cm) showed that the residual water content in the rubber-amended soil was also significant, especially at high levels of CR application.
A series of laboratory tests were conducted to obtain the bearing capacity of a square footing rested on shredded rubber-reinforced soil.
At failure, they can provide as much extra strength as polypropylene fibers if the rubber fiber-soil mixture has been consolidated to a low confining stress, although very much larger quantities are needed, even to the point of being unrealistic for engineering applications.
Riggle (1994) also stated that the inclusion of rubber particles in soil could improve soil physical properties such as aeration and water infiltration rates.
pH changes were quite different in both types of soils so that, by increasing the amount of crumb rubber, loamy sand soil's pH value decreases, whereas silty clay soil's pH was increased.
The reasons for the increase of moisture in the treatments containing CR can be attributed to increasing porosity, decreasing density and increasing surface area of rubber-amended soils.
The objective of this study was to survey the effect of crumb rubber (CR) application as soil amendment on soil water retention curve indices, soil aggregate stability and soil micronutrients.
