Effect Of Volume Ratio On Damage Of Ceramsite Concrete

In this paper, Split Hopkinson Pressure Bar (SHPB) and WAW-2000Universal testingmachine controlled by computer are used to study effect of volume ratio on failure ofceramsite concrete by doing the experiments on the cement concrete,C40concrete andceramsite concrete with different ceramsite volume ratio.The results of static experiments show that static strength of ceramsite concretedecreases with the increasing of ceramsite volume ratio.But,when ceramsite volume ratio isgreater than30%,trend of the change is slowed down.The strength of ceramsite concretespecimens with150mm×150mm×150mm and Φ70mm×35mm have no obviousdifference but have obviously different for cement concrete and C40concrete.The results of SHPB experiments show that dynamic strength of ceramsite concrete thatdecreases with the increasing of ceramsite volume ratio is smaller than dynamic strength ofcement concrete and C40concrete.At the same time,strain-rate sensitivity of ceramsiteconcrete depends on ceramsite volume ratio.Reduction of ceramsite volume ratio is benefit tothe strain-rate sensitivity.SHPB experiments on concrete under pressures of0.2MPa,0.4MPa,0.6MPa and0.8MPashows that energy absorbed by ceramsite concrete increase with incident energy.However,thechange is also slowed down with strain rate increase. At the same time,energy absorbed by thecement concrete and C40concrete has a linear relation with incident energy.The normalization pressureP of the strength between failure surface and residualstrength surface, and the increment of strain are introduced to improve the description of thefailure D. Thus the RHT model has been improved. Theoretic stress-strain curves of improvedRHT model are in good agreement with experimental ones of concrete.But,special argumentsof the model which are derived through numerical fitting using the data of ceramsite concretechange greatly.It shows that this model is unsuitable for ceramsite concrete,if the volume ratiois not considered.