基于力学性能试验的UHPC钢纤维掺量优化与性价比分析

Content optimization and Cost Performance Analysis of UHPC Steel Fiber Based on Mechanical Property test

为探究纤维含量变化对UHPC力学性能的影响并结合材料成本得出UHPC最优纤维掺量,制备了4种不同钢纤维体积含量的UHPC试件并对其进行立方体抗压、单轴抗压、弹模试验、单轴拉伸以及4点弯折试验。结果表明:UHPC的立方体抗压强度及单轴抗压强度随着钢纤维体积率的增加略有提高,且掺入钢纤维后所有测试试件均表现出良好的受压变形性能;钢纤维含量的变化对UHPC的弹模影响不大;当钢纤维掺量为1%,2%与3%时,UHPC的抗拉强度增长率为31.6%,56.4%与73.1%,抗弯折强度增长率为96.2%,202.6%和260.5%,其增长速率呈现先增加后变缓的趋势。在试验基础上采用层次分析法及价值工程对不同纤维掺量UHPC进行价值计算,当掺量为2%,价值最大为1.317,此时UHPC性价比最高。

In order to explore the influence of fiber content on the mechanical properties of UHPC and obtain the optimal fiber content of UHPC combining with the material cost,the UHPC specimens with 4 steel fiber contents are and prepared.The cube compression test,uniaxial compression test,elastic modulus test,uniaxial tensile test and 4-point bending test on the specimens are performed.The result shows that(1)the cube compressive strength and axial compressive strength of UHPC show a increasing trend with the increase of fiber content,and all the specimens shows good compressive deformation properties after adding steel fiber;(2)the change of steel fiber content has little influence on the elastic modulus of UHPC;(3)when the steel fiber content are 1%,2%and 3%,the corresponding growth rates of UHPC tension strength and bending strength are 31.6%,56.4%,73.1%and 96.2%,202.6%,260.5%respectively,showing the trend of increasing at first and then slowing down;(4)based on the experiment,the values of UHPC with different fiber contents are calculated by using AHP and value engineering,and the maximum value is 1.317 when the content is 2%,and UHPC is the most cost-effective at this time.