钢纤维高强混凝土抗冲击压缩力学性能研究

Study on Impact Compression Mechanical Properties of Steel Fiber Reinforced High Strength Concrete

混凝土遮弹层在防护工程领域使用较为普遍,通过改善遮弹层的材料性能来提高防护能级成为当前的研究重点。钢纤维高强混凝土遮弹层是一种具有高防护能级的遮弹层,对该遮弹层的材料组成部分钢纤维高强混凝土进行分离式霍普金森压杆冲击压缩性能试验研究,并借助数值模拟分析软件LS-DYNA进行比对。在试验中,对钢纤维掺量分别为0、0.5%、1.0%的高强混凝土进行冲击压缩试验。结果表明:钢纤维高强混凝土受冲击压缩作用后呈脆性破坏特征,应变率越高,动态抗压强度值越大。当钢纤维掺量达到1.0%时,在气压1.0 MPa下,其动态抗压强度值可达180.9 MPa。在同等气压条件下提高钢纤维掺量,动态抗压强度提高幅度在3%～6%之间。数值模拟验证了"应力均匀性"假定与应力波传播规律,数值模拟结果与试验结果吻合度较高,模拟方法可行。

Concrete shielding layer is widely used in the field of protection engineering. Improving the level of protection has become the current research focus by improving material properties of the shielding layer. Shielding layer of steel fiber reinforced concrete is a kind of layer with high protection level. The impact compression performance of steel fiber reinforced high strength concrete is studied by the split Hopkinson pressure bar and the numerical simulation analysis software LS-DYNA. In the experiment, impact compression tests were carried out on high strength concrete with steel fiber content of 0, 0.5 % and 1% respectively. The results show that the steel fiber reinforced high strength concrete exhibits brittle failure after impact compression, and the higher the strain rate is, the greater the dynamic compressive strength is. When the steel fiber content reaches 1%, the dynamic compressive strength can reach 180,9 MPa at air pressure 1.0 MPa, When the steel fiber content is increased at the same air pressure, the increase of dynamic compressive strength is between 3 % and 6 %. Numerical simulation verified the hypothesis of ＂stress uniformity＂ and the propagation law of stress wave. The numerical simulation results coincide with the experimental results, and the simulation method is feasible.