EVALUATING THE CRACKING RESISTANCE OF CEMENT-BITUMEN TREATED MATERIALS USING THE SEMI-CIRCULAR BENDING TEST

Abstract

Cement-bitumen treated materials (CBTM) are produced using cold recycling technologies for the rehabilitation of bituminous pavements. Bitumen emulsion and cement are used as binders, and thus jointly contribute to the mechanical performance of the mixtures. This paper focuses on the cracking resistance of CBTM, which is related to the presence and relative effect of bituminous and cementitious bonds within the mixtures. The objective is to evaluate the influence of different cement types, bitumen-to-cement ratios (1.3 and 0.8) and curing conditions (free and restricted evaporation). The semi-circular bending (SCB) test was used to evaluate the cracking resistance of mortar specimens whose composition was derived from the mixtures’ composition removing the coarse aggregates. The SCB specimens cut from gyratory compacted specimens were tested at 10 °C after 28 days of curing at 25 °C. The results analysis indicates that in the crack initiation phase, the behaviour of CBTM mortars depends on the combined presence of cementitious and bituminous bonds, whereas, in the crack propagation phase, the effects of cement type and dosage prevail and may lead to a brittle behaviour