Weak subgrade improvement with rubber fibre inclusions Available to Purchase

ABSTRACT: When roads are constructed on weak soils, stability and settlement considerations are critical. At locations having poor subgrade support, it is recommended to use alternative methods to reinforce the soil. The use of fibre materials in geotechnical design and application is advantageous because randomly distributed fibres offer strength isotropy and improve the soil performance. This paper presents experimental results on the improvement of the California bearing ratio (CBR) performance of sand by the addition of buffing rubbers. Two different rubbers – granulated rubber and fibre shaped buffing rubber – were used. Three factors were found to significantly affect the CBR values: rubber shape, rubber content and aspect ratio. Test results revealed that changes in properties of sand caused by reinforcement were sensitive to the aspect ratio of the rubbers. Fibre inclusions with optimum aspect ratio increase the CBR of the subgrade and hence may cause a substantial decrease in design thickness of the pavement. Fibre inclusions mixed with subgrade will provide needed tensile strength under traffic loads.