Preparation And Resistance Of Light-weight And High-strength Ceramsite Concrete Study On Freezing Properties

Light weight and high strength concrete is one of the development directions of the current concrete technology.Lightweight high strength concrete from the light perspective,add some light materials such as ceramsite,reduce the density of relatively high slurry,to achieve the light effect;from the perspective of strength,increase the quality and strength of powder,strength,and the quality of concrete increased.Therefore,it is necessary to continuously calculate and test and match to seek the optimal binding point of lightweight and high strength.In this thesis,lightweight material-ceramsite is used to replace a certain proportion of conventional concrete aggregate,and to reduce the density and increase its strength through theoretical calculation and trial allocation.A series of orthogonal tests are used to prepare high strength concrete and ceramsite concrete.Because of its certain water absorption,the influence of the lightweight and high strength ceramsite concrete on the strength is analyzed.The main research contents and results are as follows:(1)The strength of the concrete increases with the improvement of the cement grade;the high strength concrete has less large cracks,more uniform pore distribution,and the number of pores in the middle of the test block is more than the outside.(2)The average density of clay concrete and shale concrete is 1256 kg/m~3and 1307kg/m~3respectively;the compressive strength of shale concrete is higher than that of clay concrete,and the replacement rate is negatively associated with the concrete test block density and age strength.(3)Epoxy resin curing agent and 650 polyamide resin to encapsulate ceramum can solve the problems of ceramum floating and upper surface;the density difference of the encapsulated and unpackaged ceramic particles is small,and the average compressive strength of 3 and 7 days is not much different,and 28 days is significantly higher than that of unencapsulated ceramum concrete.(4)The minimum density of 1320 kg/m~3,1338 kg/m~3and 1329 kg/m~3,and the average compressive strength of 3 days,7 days and 28 days is 16.2MPa,23.4MPa,34.1MPa.The average tensile strength of split is 1.46MPa,and the average damage load is 22.92KN.The split tensile strength value and the fluctuation range of breaking load are not large.Compared with ordinary concrete,the strength is increased by about 12%,and the density is reduced by 44.6%.(5)Since the strength of ceramsite itself is lower than that of cement cement,ceramsite and its surrounding concrete are first destroyed during the freezing and thaw cycle,and then the cracks develop inside the concrete;after 25,50 and 100 cycles,the mass and strength loss rates are 1.71%,10.1%,4.17%and 19.8%,6.52%and 30.3%,respectively.With the decrease of the density,the large pores in the concrete increase,and the freeze-thaw damage intensifies.