基于正交试验的低温湿喷混凝土力学性能与配比优化研究

为了研究养护温度、钢纤维、减水剂和速凝剂的掺量这4种因素在低温环境下对湿喷混凝土力学性能的影响规律并对其配比进行优化，对湿喷混凝土的早期强度和后期强度进行了极差分析以及方差分析，利用Duncan法事后比较得到初步配比，并建立了湿喷混凝土早期和后期强度回归模型。研究表明：养护温度对于湿喷混凝土早期、后期的抗压强度影响最为明显，前期抗压强度钢纤维掺量影响最弱，后期强度速凝剂掺量影响最弱。在方差分析中，钢纤维、减水剂掺量和养护温度对湿喷混凝土的早期、后期强度都有极显著影响，而速凝剂掺量则仅对早期强度有极显著影响，后期强度无显著影响。基于Duncan法事后比较可得到湿喷混凝土精度略差的初步配比，后续利用回归强度模型实现对湿喷混凝土配比的高精度优化。通过数据模型结合矿山要求得出湿喷钢纤维混凝土最优配比：钢纤维掺量42.496 kg/m³、减水剂掺量7.989 kg/m³、速凝剂掺量66.910 kg/m³,同时最佳养护温度为12℃。

Optimization study on mechanical properties and ratio of low-temperature wet spray concrete based on orthogonal test

The extreme difference analysis and variance analysis of the early and late strength of wet spray concrete were studied, and the preliminary ratio was obtained by the duncan method after the fact, and the early and late strength of wet spray concrete was established to study the influence of four factors on the mechanical properties of wet spray concrete under low temperature environments and optimize its proportion. The results show that the effect of curing temperature on the compressive strength of wet spray concrete in the early and late stages is the most obvious, the influence of the steel fibers of the early compressive strength is the weakest, and the effect of the doping of the late strength quick-setting agent is the weakest. In the dispersion analysis, the amount of iron fibril, the amount of water reducer, and the solidifying condition have a notable impact on the early and late strength of wet spray concrete, and the amount of quick-setting agent only has a notable consequence on the initial intensity and the later strength has no notable consequences. Based on the Duncan method, the preliminary ratio of wet spray concrete can be obtained by the after-the-fact comparison, and the subsequent regression strength model can realize the high-precision optimization of the wet spray concrete dispensation. The ideal dispensation of wet spray iron fibril concrete was obtained by combining the data model with the mine requirements: the steel fiber dosage was 42.496 kg/m3, the water reducer dosage was 7.989 kg/m3, the quick-setting agent was 66.910 kg/m3, and the optimal curing temperature was 12 °C.