Effects of termiticides type on workability, hydration characteristics and mechanical property of cementitious materials

The addition of termiticides in concrete is gaining in popularity as method to prevent the degradation of concrete material and structure by the penetration and attack from termiticides, while the effect of which has not been systematically investigated yet. In this paper, the effects of five new generation termiticides on workability and hardened property of cementitious paste and mortars, in terms of minislump, compressive and flexural strength, were investigated. Moreover, the hydration characteristics, including microstructure and hydration products of the cementitious pastes with the termiticides were determined by X-ray diffraction test (XRD) and scanning electron microscopy (SEM). The results illustrated that the incorporation of the termiticides increased the workability while it decreased the compressive and flexural strengths of both paste and mortar. Moreover, the addition of termiticides did not affect the type and quantity of hydration products, especially for the calcium hydroxide. The exception was imidacloprid, in which it damaged the microstructure of cement paste. Based on the investigation, two termiticides, in terms of bifenthrin and chlorpyrifos, were identified as the termiticides with better performance in preparing termite-resistant concrete.