Experimental Research On Macro Properties Of Air-entrained Pumice Concrete Based On The Analysis Of Pore Structure

With the development of science and technology,the instruments to explore the internal microstructure of concrete are more and more advanced,the precision is higher and higher,and the degree of automation is more and more high.It provides us with accurate and efficient means to uncover the mysterious veil in the concrete.However,most of the research is concentrated on ordinary concrete,and the research on lightweight aggregate concrete with light,easy to get and better insulation as coarse aggregate remains to be further studied.Therefore,using natural pumice as coarse aggregate,the working performance,mechanical properties,durability and micro performance of three kinds of pumice concrete mixed with different air entraining agents were investigated.In this paper,through the observation of the three-dimensional bubble hole,the bubble parameters of the pumice concrete are measured by the air bubble spacing analyzer.Through the fractal theory,the complexity of the bubble is verified.Finally,the main factors affecting the strength,tension ratio and durability of the pumice concrete are analyzed by the grey relation idea,and the GM model is built with the aid of the model.The prediction model of pore structure parameters on compressive strength of pumice concrete is established.The results of the study show that:1.The addition of air entraining agent will reduce the compressive strength and splitting tensile strength of pumice concrete,but adding a certain amount of air entraining agent can improve the brittleness of pumice concrete.2.Adding proper amount of air entraining agent can improve the frost resistance of pumice concrete.3.Through the fractal theory,it is concluded that the air entraining agent is more complex than the inner air bubble in the concrete without air entraining agent in a certain range,but the air entraining agent is mixed with excess air entraining agent to make the internal bubble structure become single,which is not conducive to the performance of concrete.4.According to the grey relation idea,the biggest factor that affects the compressive and splitting tensile strength of pumice lightweight aggregate concrete is the coefficient of air bubble spacing.The biggest factor affecting the tensile ratio of concrete is the average string length,and the biggest factor affecting its frost resistance is the specific surface area.The influence of concrete content after hardening on the strength and durability of concrete is relatively small.5.Based on the GM model,it is reasonable to predict the strength of pumice concrete by the amount of air entraining agent.