Study On Cement-based Permeable Crystalline Material And Nano-calcium Cabonate Modified Concrete

Concrete has been an important building material since its birth.With the development of society,the strength and durability of ordinary concrete can not meet the needs of social development for high-performance concrete,so it is of great significance to study concrete with higher performance,the current cement-based permeable crystallization type materials and the application of nano material in the concrete research provides new ideas.In this paper,XYPEX admixture in cement-based permeable crystalline material and nano-calcium carbonate admixture in nanomaterial were synthesized by experiments.Through mechanical properties test and durability test,the improvement of mechanical properties and durability of concrete was studied.The results are as follows:（1）An appropriate amount of XYPEX mixture can improve the compressive strength and splitting tensile strength of concrete,and the optimal dosage is 1%.Nano CaCO3 material has a weakening effect on the mechanical properties of ordinary concrete,the reduction can be about 20%.（2）The compound mixing of XYEPX mixture and nano-CaCO3 can improve the mechanical properties of concrete,and the optimal mixing amount is 3%XYEPX mixture and 0.5% nano-CaCO3,and has a great impact on the early mechanical properties of concrete,but the influence on the mechanical properties of 28 D concrete is weaker than that in the early stage.At the same time,compound XYEPX mixture and nano CaCO3 have a greater improvement in early mechanical properties of concrete than single-doped XYPEX mixture,but the strength improvement at 28 d is lower than single-doped XYPEX mixture.（3）Compared with the benchmark concrete,concrete mixed with XYPEX mixture and nano-CaCO3 can enhance the freezing resistance of concrete to a certain extent.The optimal content is 1% XYPEX mixture and 1% nano-CaCO3.