The basic mechanical properties of high performance concrete and very high performance concrete with and without reinforcement

Experiments were carried out to study the mechanical properties,including the cubic strength,prismatic strength,Young's modulus,strain a t peak stress,etc.,of pumped High Performance Concrete(HPC)and Very High Performance Concrete(VHPC)using crushed stone aggregates and g ravel aggregates,with and without t ransverse confinement,from lower to higher strength.Test and analysis showed that the basic mechanical performance o f HPC with gravel aggregates were the same as th ose of HPC with crushed stone aggregates.As for HPC without reinforcemen t,the ratio of prismatic strength to cubic strength of HPC,the strain at peak stress and the Young's modulus of HPC we re higher than that of the Normal Strength Concrete(NSC).Before the peak stress,the stress-strain curve of HPC was approximately straight line,which differed from that of NSC.After the p eak stress,the shape of the curve became very steep due to the brittleness of HPC.As for HPC with hoop reinforcement,ab out 20%～35%and 32%～66%enhancements were obtained for the s trength and strain at peak stress.The stress-strain curve descending mo re slowly in comparison with that of plain HPC showed good ductility.Comparison of th e test results of this study and other literatures indicated that the ductility of HPC in this study was better a nd the Young' s modulus was lower.