Size Effect Of Strength Test For Waste Glass Concrete

Today,green,recycling and sustainability have become the development theme,and solid waste treatment is the main problem facing the world.The application of waste glass in concrete can not only promote the development of new concrete,but also play a dual effect of environmental protection and economy.In practical engineering,due to the large size of the structure,it can only be studied by scale simulation,so it is difficult to analyze the mechanical properties.Therefore,in order to apply the waste glass concrete to the building structure,it is important to study the size effect of its mechanical properties systematically.In this paper,the compressive strength and splitting tensile strength of glass concrete are studied in terms of the replacement rate of glass aggregate,the replacement form of glass aggregate,and the addition of metakaolin.The size effect of waste glass concrete is studied from two aspects of strength test and theoretical analysis.The main research contents are as follows:(1)The size effect of compressive strength and splitting tensile strength of 144 Cube Specimens with side length of 100 mm,150 mm and 200 mm is studied.The results show that the strength of waste glass concrete decreases with the increase of specimen size,and the size effect increases with the increase of replacement rate of glass aggregate When the replacement rate is 100%,the size effect degree changes most significantly;the use of metakaolin instead of 20% of cement in glass concrete can not only inhibit the alkali silica reaction,but also improve the compactness of the concrete,so as to improve the strength.(2)On Weibull statistical theory of size effect,Bazant based on energy release theory of size effect and Carpinteri multifractal theory of size effect on the basis of comprehensive analysis and study,the compressive strength and splitting tensile strength and the theory of size effect formula fitting,the results show that the mechanical properties of size effect formula not only applies to the concrete,concrete also applies to glass.(3)Through comparative analysis of the three size effect theories,and based on the results after fitting the test data with theoretical formula,a consistent conclusion is obtained:the test data are closer to the Bazant size effect law curve,indicating that Bazant size effect theory has good applicability.(4)According to the size effect theory curve,the critical size and the critical strength are calculated.The results show that the maximum critical size is obtained based on the Bazant size effect theory.The critical strength value obtained by the multi-fractal size effect theory curve of Carpinteri is the closest to that obtained by the Bazant-xiang modified size effect theory curve.Although the two size effect theories have different foundations,the results are consistent.The critical size increases with the increase of compressive strength.