Evaluation of Basic Properties of Cement Asphalt Mortar Depending on Specific Surface Area of Nonionic Emulsified Asphalt

Abstract

This study was designed to evaluate the physical properties of cement asphalt mortar (CA mortar) according to the specific surface area (SSA) of nonionic emulsified asphalt. CA mortar specimens were prepared using 3 types of nonionic emulsified asphalt with different SSA and 1 type of rapid hardening cement and sand, additives. The physical properties of CA mortar were evaluated by measuring the temperature variation, bleeding ratio, flow value, air content, compressive strength, and expansion ratio. Test results showed no temperature variation and bleeding in any CA mortar specimens, indicating that SSA change of emulsified asphalt did not induce material separation of the mortar. As a result of the flow value test and compressive strength test, it was confirmed that the flow value and compressive strength increase of specimen CAM-A3, with the largest SSA of emulsified asphalt, increased the hydration reaction rate between cement and emulsified asphalt. CAM-A1 and CAM-A2, which did not satisfy the standard of air content, required adjustment of amount of added anti-foaming agent (AFA) and air entraining agent (AEA). The expansion ratio of CAM-A1 exceeded the standard, because the amount of self-shrinkage caused by hydration reaction is less than the amount of expansion caused by addition of aluminum. To accurately analyze the effect on SSA of emulsified asphalt, additional studies such as tissue observation through a scanning electron microscope are needed.