Title: Micro hardness of interface between cement asphalt emulsion mastics and aggregates

Author(s): Zhenjun Wang, Aimin Sha

Publication: RILEM

Volume: 43

Issue: 4

Appears on pages(s): 453-461

Keywords: Cement asphalt emulsion mastics, Interface between mastics and aggregate, Micro harness, Micro hardness test apparatus, Micro hardness test apparatus

DOI:

Date: 4/6/2010

Abstract:
Characteristics of interface between cement asphalt emulsion mastics and aggregate is different from that of interface between cement and aggregate or asphalt and aggregate. A novel method was put forward to evaluate interface character of mixtures in the paper. MH-5 micro hardness apparatus was adopted to study influences of fillers’ fineness, aggregate lithology and different type of cement on micro hardness of the interface between the mastics and aggregate; and some micro test apparatuses, such as SEM, XRD and EPMA, were used to analyze its mechanism. Results indicate that the increase of cement and mineral filler fineness is favorable to improve micro hardness of the interface, but over fine mineral filler is disadvantageous. In contrast to granite and granite filler, limestone and limestone filler are more helpful to increase the hardness value. Lithology changes of mineral filler have greater influences on the hardness than those of aggregate. The micro hardness value first increases, then decreases with the increase of mineral filler/asphalt emulsion (MF/AE) ratios. There exists an optimal ratio, which is 1.1. Adopting the high strength cement is an effective way to improve the micro hardness.