Early hydration properties and performance evolution of phosphoaluminate cement concrete

As a novel cementitious material, phosphoaluminate cement (PAC) has the characteristics of early strength and high strength. The early hydration properties of PAC were investigated, and the influence of curing age on concrete strength, anti-permeability, surface ventilation and micro structure was analyzed. Moreover, the inherent correlation between hydration mechanism and process of PAC was explored deeply by different test methods. The research results indicate that the curing age has significant effects on the performance development and micro structure of the concrete. The variation of concrete strength with curing age can be expressed by a Boltzmann function. Besides, the changes of relative permeability coefficient of anti-water permeability and chloride diffusion coefficient with curing age meet an exponential function. There exists a good linear relationship between natural logarithm of permeability pressure of concrete surface and time. The early hydration process of PAC is consisted of four stages, i.e., dissolution, induction, acceleration and deceleration. (C) 2019 Elsevier Ltd. All rights reserved.