Experimental Study On Capillary Absorption Of Solid Waste Concrete Under Sustained Compressive Loading

At present,the research on the water transport process in concrete is limited to the analysis of concrete permeability coefficient,chloride diffusion coefficient and the amount of electricity,capillary absorption as the main way of water transport in concrete,related research is less.And most studies are based on undamaged or uninstalled concrete,which is inconsistent with the actual work of the structure.In order to solve this situation,this article considers the force of the concrete structure in actual service,and studies the capillary absorption process of concrete under the sustained loading.The C30 concrete is designed with single mixing fly ash and coal gangue.On this basis,a cylindrical specimen with hollow inner cavity is used as the test object to realize the coupling effect between the load and the water absorption.The cumulative water content and sorptivity of fly ash and coal gangue concrete under the sustained compressive loading were studied;The influence of fly ash,coal gangue content and loading level on cumulative water content and sorptivity was analyzed,and the corresponding mathematical model was established as well.Through the data analysis,the following main conclusions are drawn:(1)The compressive loading has an impact on both cumulative water content and sorptivity of concrete.A mathematical model of the quadratic polynomial was been satisfied approximately between cumulative water content,sorptivity with loading level.(2)Fly ash can effectively improve the impermeability of concrete.The cumulative water content and sorptivity of concrete decreased with the increasing of fly ash content by the negative exponential function,and the addition of fly ash decreases the sensitivity of cumulative water content and sorptivity to the loading level.(3)Spontaneous combustion gangue instead of crushed stone as coarse aggregate will make the concrete cumulative water content and sorptivity increased.The cumulative water content and sorptivity increased with the increasing of coal gangue by the exponential function,and compared with ordinary concrete,the water absorption performance of coal gangue concrete is more sensitive to loading level.