活性粉末混凝土的常规三轴压缩性能试验研究

通过活性粉末混凝土在不同围压下的常规三轴压缩试验,研究活性粉末混凝土的破坏形态、强度特征和变形规律。结果表明:围压≤60 MPa时,活性粉末混凝土的常规三轴压缩破坏形态主要表现为劈裂破坏,围压为65MPa时,破坏表现出挤压流动特征;在不同的围压条件下,活性粉末混凝土试件的应力—应变曲线的形状基本相似,均经历压密、弹性、应力软化和荷载稳定下降4个阶段;活性粉末混凝土的三轴抗压强度、弹性模量和轴向峰值应变均随围压的增大而近似线性增长,但活性粉末混凝土的三轴抗压强度随围压增长的速度较普通混凝土缓慢;在到达峰值应变之前,活性粉末混凝土的割线泊松比表现出随围压的增大而减小的规律,此阶段的体积应变表现为压缩。

Experimental Research on the Conventional Triaxial Compressive Properties of Reactive Powder Concrete

Through conventional triaxial compression tests of reactive powder concrete(RPC) cylinder specimens under different confining pressure,the failure mode,strength characteristics and deformation law of specimens are studied.Results indicate that RPC failure mode under conventional triaxial compression is splitting failure in the main as the confining pressure is less than or equal to 60 MPa.When the confining pressure is up to 65 MPa,RPC failure behaves squeeze flow characteristics.The shapes of the stress-strain curves of RPC specimens are basically similar under different confining pressure.There are four stages which can be expressed as pressure consolidation,elasticity,stress softening and load steadily decreasing in the curves.RPC triaxial compressive strength,elastic modulus and axial peak strain increase almost linearly with the increase of confining pressure.But the growth rate of RPC triaxial compressive strength along with the increase of confining pressure is lower than that of normal concrete.Before peak strain,the secant Poisson ratios of RPC decrease with the increase of confining pressure and the volumetric strain of the stage behaves compression.