Study On The Relationship Between Microstructure And Compressive Strength And Durability Of Lightweight Aggregate Concrete

Since the concrete was born, it become the world’s most widely used and most indispensable building materials by its advantages. Like its simple materials, easy molding, cost advantages. The Lightweight aggregate concrete use the natural pumice as aggregate,which is abundant reserves in Inner Mongolia. Compared with ordinary concrete, Compared with ordinary aggregate concrete, it has the advantages of small self weight, excellent thermal insulation properties and strong frost resistance. Lightweight aggregate concrete is widely used in most parts of North China.The disadvantages of lightweight aggregate concrete are as obvious as the advantages. Its natural weakness is weak compressive strength. To improve the mechanical properties of lightweight aggregate concrete has been the focus of research at home and abroad. Due to the characteristics of concrete inside, the macro performance can often be explained by the micro properties of concrete. It has important significance to study the pore structure of concrete. In recent years, since the fractal method is put forward, it promoted the research process of the micro morphology of concrete greatly. The change of water cement ratio is the most influential factor to the change of meso structure of concrete.Therefore, this paper focuses on the research of LC30 concrete with three different water cement ratio. Do the compressive strength test, frost resistance test and micro pore structure test with three groups of concrete. According to the experimental phenomena and results, study the effect of water cement ratio on the changes of the lightweight aggregate concrete pore structure. Analysis the change regularity of bubble characteristic parameters and the macro mechanical properties with different water cement ratio. In different freeze-thaw times, describe the changes of internal pore structure of lightweight aggregate concrete and macro mechanical performance changes. Fractal dimension has been used to describe the complex distribution of concrete internal voids. Find out the connection between the pore structure,mechanical properties and frost resistance durability of light aggregate concrete. And then, establish the relationship between the fractal dimension and the residual life after freeze-thaw damage of lightweight aggregate concrete. Predict the remaining service life of concrete under the condition of freezing and thawing more accurately. In order to provide a theoretical basis for the simple inference of the remaining life of concrete.