Experimental study on pore structure and mechanical property of chemical foaming foam concrete

Abstract

In this paper, foam concrete (FC) was prepared by chemical foaming method. Besides, the effects of different density grades and fly ash content on the pore structure of FC and the mechanical response of FC under static and dynamic forces were discussed. At the same density grade, the FC strength shows the feature of first increasing and then decreasing with the increase of fly ash production. The pore diameter of FC prepared with protein foaming agent is between 60-800µm, with the uniform pore distribution. The higher the density grade, the smaller the proportion of irregular pores in the FC and the larger the proportion of round pores.When the fly ash content is relatively small, the pore diameter inside the concrete can be significantly reduced, and the pore shape develops more like a circle. When the external dynamic strain rate increases from 10-5/s to 10-3/s, the uniaxial compressive strength of the FC test sample increases by about 14.1%, and the triaxial compressive strength increases by about 61.9%. Therefore, FC exhibits typical ductile failure characteristics under dynamic stress, which can significantly delay the impact of dynamic loads such as earthquakes and explosions. This is of great significance for the engineering application of FC.