Research On Static And Dynamic Tensile Fracture Properties Of Concrete

The study of tensile properties of concrete is one of the weak points of the studies about strength of large concrete construction.Based on the tensile failure of concrete under the condition of penetration or other dynamic conditions,in this paper,the Brazilian disc test method was used to study the properties of concrete materials under different loading conditions and loading rates.The Young's modulus,strength and fracture toughness of the mortar and concrete specimens under different loading conditions were obtained.Research indicates:With the increase of loading rate,the tensile strength of the two materials showed an increasing trend,indicating that the strain rate has a significant impact on the tensile properties of materials,and tensile strength increases with the increase of the strain rate.With the increase of loading rate,the tensile strength of the concrete specimen increases from the static lower than the mortar sample strength to higher than the mortar sample,which indicates that the strain rate effect of the concrete is more obvious.When static loading,the tensile strength of concrete specimens is lower than mortar specimens',mainly due to the interfacial effect of tensile crack propagation along the interface between aggregate and mortar.However,the tensile failure of the concrete partially crosses by aggregate at high loading rates.The results also show that the tensile strength and fracture toughness of the specimen increase with the increase of the ratio of diameter to thickness.The dynamic tensile tests of mortar and concrete were carried out after they were predamaged.The test results show that with the increase of pre-damage degree,the tensile strength of mortar and concrete materials are obviously reduced.