高性能混凝土早龄期拉伸特性试验研究

通过自行设计的试验装置对三种不同配合比的高性能混凝土在3d龄期以内的极限拉应变、拉伸徐变、抗拉强度和拉伸弹性模量等与混凝土早期开裂密切相关的材料特性进行试验研究。试验结果表明:所采用的试验方法可有效地用于评价早龄期高性能混凝土的轴向拉伸特性;硬化过程中高性能混凝土的极限拉应变极高,并随龄期迅速递减至最小值,之后缓慢回升并渐趋稳定;加载龄期越早,高性能混凝土的拉伸徐变发展越快,量值越大;1d龄期内高性能混凝土的抗拉强度、拉伸弹性模量发展极为迅速。

EXPERIMENTAL INVESTIGATION OF TENSILE BEHAVIOR OF HIGH PERFORMANCE CONCRETE AT EARLY AGES

Direct tensile behaviors of HPC with 3 different mix proportions at the age of 3 d were investigated with self-designed testing rig in this paper. The results of the present study can be drawn as follows: a) testing rig developed in this study effectively evaluated direct tensile behaviors of hardening HPC; b) ultimate tensile strain of HPC was very high in the period of hardening,which rapidly decreased with age and minimum value was reached later (about 12 hours); c) tensile strength and tensile modulus of elasticity of HPC rapidly developed within 1 d.