关键词: 单轴冲击压缩, 应变率, 动态强度增长因子, 早龄混凝土

Abstract: In order to study the dynamic mechanical properties of northwest artificial negative temperature early age high strength concrete, the impact compression tests were conducted on different age of high strength concrete at -7℃ on SHPB apparatus. In the SHPB tests, a lot of stress-strain curves were gained with different strain rate. It is found that the effects of curing environment temperature on high strength concrete strength greatly. Under the standard and -7℃ curing environment, the 3d strength of concrete specimens are 77.4% and 46.7% of the uniaxial compressive strength respectively. At low strain rate, brittleness of negative temperature concrete is more obvious. In the medium-high strain rate (more than 30s-1), the toughness of negative temperature concrete increases, but brittleness decreases. The dynamic compressive strength and peak strain have obvious strain rate relationship. Three age peak strains are in 0.002~0.004. Under the same strain rate and age of concrete, the strength and elastic modulus increase with the impact number decreases, on the contrary, the peak strain increases.