Effect of solution road RomixSoilfix on deformation performance of granular base material: A laboratory and field investigation

Abstract

Granular base material (GBM) is widely used as a base course in flexible pavement, since it has good performances to disperse stress and resist deformation. However, due to the increasing cost of pavement construction resulted by the low stiffness of GBM, the application of flexible pavement was rarely reported in Chinese expressways. This paper aimed to investigate the effect of Solution Road RomixSoilfix (SRX) on deformation performance of GBM and to evaluate the feasibility of SRX modified GBM (SRX-GBM) as a flexible base in expressway structure. A series of experimental tests were performed to analyze the influence of SRX content on curing process, stability and deformation performance of SRX-GBM. Subsequently, a flexible pavement was constructed using the SRX-GBM base course at the field sections on Tengchong to Longchuan Expressway in Southwest China. Results show that the use of SRX improves the California bearing ratio (CBR) of GBM, which raises from 145% to 417%. The dry shrinkage resistance and water stability of SRX-GBM are obviously better than cement-stabilized macadam. The results of triaxial tests demonstrate that the resilient behavior of SRX-GBM is dependent on the stress characteristics and curing times. The existing stress-related model is available for evaluating the changes of stress contribution to the Mr with the increase of SRX content. Since the base course has a high residual moisture content in a humid climate, the CBR of 250% was proposed by field CBR and deflection tests as a criterion for controlling curing time.