Influences of an artificial three-dimensional cementitious network on the fracture property of cement casting asphalt mixture

Abstract

Taking good advantage of both rigid cement and flexible asphalt mixture, cement casting asphalt mixture is developed to address the traditional distress in asphalt pavement. However, the relatively poor cracking resistance of CCAM limits its application in practice. Since the cracking mechanism of CCAM is still unknown, modification on the mixture design of CCAM cannot be done. In this regard, this paper focuses on investigating the influences of an artificial three-dimensional cementitious network on the fracture property of CCAM. In order to simulate the cementitious network, the pore structure in the prism sample is formed by using plastic foam balls of different sizes. The mechanical properties of beam samples at different curing days are measured. The semi circular bending test is used to characterize the strength and fracture properties of CCAM with different grouting materials. It is shown that the pore structure lowers the strength of the prism beams. Pore structures would induce more loss to the compressive strength of the beam samples than to its flexural strength. The cracking resistance of CCAM is determined by the asphalt mixture skeleton and cement network by analyzing the fracture energy and FI data. It is found that the compressive/flexural (C/F) ratio of the prism beam with 1 cm diameter plastic foam balls correlates well with the FI result of the CCAM. The results show that a moderate C/F ratio would make CCAM have fracture energy and flexibility, which makes it difficult for cracks to readily initialize and develop. The findings in this paper would provide guidance for the further selection of cementitious materials for the fabrication of CCAM with an excellent pavement performance.