Effect Of Ceramic Admixture On Properties And Structure Of Concrete Under Freeze-thaw Environment

Concrete is one of the most important civil engineering materials in modern times,which is widely used and has become an irreplaceable main material in modern buildings.The development of the new era and the implementation of the sustainable development strategy put forward higher requirements the development of concrete.In the 21st century,concrete research will mainly focus on two focuses:one is to solve the problem of concrete durability,the other is to put concrete on the road of green and sustainable development.Research on the sustainable development of concrete has become increasingly important in recent years.Considering that China is a country in the high production and consumption of ceramics,if ceramic polishing powder can be used as concrete mineral admixture,it can reduce environmental pollution,and realize sustainable economic and social development as a new measure for reuse of ceramic waste.In this paper,the ceramic polishing powder waste produced in the production stage of ceramic tile.The waste is used as concrete single admixture and with mineral powder to replace the cement to make concrete and subjected to research.The research mainly includes the macroscopic properties and microstructure of concrete.The former includes mechanical properties,durability and mechanical properties under freeze-thaw cycles,Nuclear magnetic resonance(NMR)pore testing and environmental scanning electron microscopy(SEM)analysis on microstructure.The main factors effecting the properties of concrete are analyzed by the correlation degree of grey entropy.The results of the research show that:1.The addition of ceramic polishing powder can improve the compressive strength of concrete,the amount of single admixture is more than 5%and double doping 10%(with 20%mineral powder),the strength of concrete will decrease.2.During the freeze-thaw cycle,the mass loss of ceramic concrete is small,the mass loss rate is not up to 5%after 200 freeze-thaw cycles.The frost resistance of concrete mixed with mineral powder and ceramic powder is better than that of single ceramic powder concrete.3.The porosity and bound water saturation of concrete decrease after freeze-thaw cycles.The T2 spectral area of ceramic powder-mineral powder concrete is smaller,and the proportion of less damage pores(0.02～0.05μm)and harmless pores(<0.2μm)is higher than that of single ceramic powder concrete.The internal pore structure of concrete mixed with ceramic polishing powder and mineral powder is improved.4.Through the correlation analysis of grey entropy,the factor that have great influence on the compressive strength and frost resistance of ceramic concrete is the bound water saturation.5.Comprehensive compressive strength,frost resistance and internal porosity,20%mineral powder and 10%ceramic powder should be used as concrete compound mineral admixture.