Experimental investigation on the interfacial shear bond performance of non-water reacting polymer and concrete

Non-water reacting polymer is widely used in the construction and trenchless rehabilitation of underground spaces and concrete pavement structures. The damage mechanism of interface between polymer and concrete is crucial, but is yet still unclear. In this study, Shear tests of the polymer-concrete composite specimens with different surface roughnesses and polymer densities were conducted, and the fitting model of the bond strength with the polymer density and surface roughness were derived. The failure characteristics of the composite specimens were studied by acoustic emission technology and the microstructure features of polymer in the edge, middle, and interface positions were analyzed by scanning electron microscope. The interface bond strength increased significantly with the increased of polymer density when the polymer density was larger than 0.15 g/ cm3. For polymer-concrete composite specimens with different polymer densities and surface roughnesses, the failure modes of the specimens are quite different and the failure modes can be divided into polymer matrix failure, interface failure and concrete matrix failure. AE activity exists throughout the failure process of polymerconcrete specimen and is most significant in the final failure stage. The accumulative AE ringing counts and energy sharply increase indicated that the specimen is about to fail. The polymer cell structure at the interface and edge positions can be divided into three areas: high-density cell structure, belt-shaped continuous area and low-density cell structure area, and the interface polymer cell structures were affected by the polymer density and the interface roughness. The work provides a better understanding of the influencing factors, failure modes and damage mechanism of the bond performance between non-water reacting polymer and concrete.

Automated summary

In this study, the bond strength, failure modes, and microstructure features of non-water reacting polymer and concrete interface were investigated. The results showed that the interface bond strength increased with the increase of polymer density. Different failure modes were observed for specimens with different polymer densities and surface roughnesses. Acoustic emission activity indicated the approaching failure of the specimen, and the polymer cell structure at the interface was influenced by polymer density and interface roughness.