Mechanical Behaviour of Sand-Rubber Mixtures with Cementation as a Mitigation Option

Abstract

Number of landfilled end-of-life tyres is growing due to the rapidly increasing number of the vehicles on the road all around the world which creates significant environmental and economic concerns. One of the effective ways of dealing with stockpiled scrap tyres is recycling and reusing them for a variety of purposes including engineering projects. Previous studies show that tyre derived material can be used as an alternative or replacing material in engineering projects which can also help to meet the demand for construction material. However, the mechanical behaviour of the mixtures requires further understanding to be effectively applied in any engineering projects. The mixing ratio of the materials, mean grain size between the soil and tyre derived material, sample fabrication method, initial sample conditions, and confining stress are among many other factors which affect the mechanical behaviour of mixture.
A comprehensive experimental research programme was employed in this research to define the effect of rubber fraction on the mechanical behaviour of sand and sand-rubber mixtures. Rubber and sand materials with the same particle size distributions are used to eliminate any possible contrast effect due to particle size differences. One way to mitigate the effects of the rubber on the behaviour of sand-rubber mixtures which include high compressibility and lower stiffness is to produce some reinforcement through the addition of cement. Lower level of cement is, therefore used, and both sand-rubber and cemented sand-rubber mixtures were tested in one-dimensional confined compression tests, conventional triaxial tests, and cyclic triaxial tests. The test results indicated that the stiffness of mixtures increases with cementation, and the compressibility is decreased. Samples with cementation shows a more brittle behaviour which is more dominant with decreasing confining stress. However, the stiffness and strength of the mixtures is still greatly affected by the fraction of rubber material.

Date of Award	19 Mar 2024
Original language	English
Awarding Institution	University of Bristol
Supervisor	Erdin Ibraim (Supervisor) & Andrea Diambra (Supervisor)