Experimental Study on Performance of Cement Stabilized Macadam Modified with Composite Agent

Abstract

In this paper, three composite agents (i.e. emulsified asphalt, EA; styrene butadiene rubber, SBR; rubber powder, RP) were employed to modify the cement stabilized macadam (CSM) for the optimal design of semi-rigid base materials. The feasibility of utilizing EA/SBR/RP composites in the cement stabilized macadam is investigated from the perspectives of the modification mechanism and durability performance. To investigate the effects of different modifiers on the modification mechanism of the cement stabilized macadam, the unconfined compressive strength (UCS), indirect tensile strength (ITS), and compressive resilience modulus (CRM) of the modified samples with the variations in EA/SBR/RP composites groups were tested. Moreover, the drying shrinkage test and temperature shrinkage tests are performed to reveal the effectiveness of EA/SBR/RP composites on durability performance of cement stabilized macadam. The results show that the UCS, ITS, and CRM of the samples decrease with the increasing of EA/SBR/RP composites during 28 days. The average drying shrinkage coefficient (DSC) increases with the increasing of EA/SBR/RP composites. Considering all the above experimental results, the recommended dosage of the composite agent is 2% EA, 0.75% SBR, and 0.6% RP.