Mechanical properties and damage analysis of rubber cement mortar mixed with ceramic waste aggregate based on acoustic emission monitoring technology

Abstract

Adding rubber particles into mortar or concrete has become one of the green ways to deal with waste rubber from the transportation industry. On this basis, this study proposes the addition of ceramic waste aggregate (CWA) to solve the issue of mortar strength reduction after the addition of rubber. This paper mainly analyses the mechanical properties of rubber cement mortar (RCM) mixed with different contents of CWA and the damage analysis of composite mortar in the three-point bending test by using acoustic emission (AE) monitoring technology. The flexural test and compressive test show that the mechanical properties of composite mortar can be greatly improved by adding CWA into the mortar. With increasing CWA content, the strength first increases at low content and then decreases at high content due to the high water absorption of the aggregate. At the same time, combined with AE technology, the cumulative energy, cumulative number of hits, Ib-value analysis, intensity analysis and RA-AF value analysis of different kinds of composite mortar are analysed and compared. Based on the AE source location and damage index, the fracture damage characteristics of three kinds of mortar in the three-point bending test are described. The frequency analysis of the AE signal is carried out by the wavelet packet transform (WPT), and the energy percentage change of the AE signal within a specific frequency interval is analysed. Based on the above AE analysis method, the three kinds of mortar have different AE signals, corresponding to different fracture characteristics. This paper provides the basis of mechanical and AE tests for a new type of green composite mortar.