为研究钢纤维、聚乙烯醇（polyvinyl alcohol, PVA）纤维和矿粉3种因素对钢-PVA混杂纤维高性能混凝土（hybrid fibre high performance concrete, HFHPC）高温后的爆裂行为和立方体抗压强度。对钢纤维、PVA纤维和矿粉3种因素采用正交试验设计，并进行高温爆裂试验以及立方体抗压强度试验，利用扫描电镜（scanning electron microscopy, SEM）对不同温度后的HFHPC试件微观结构进行观察分析。结果表明：钢-PVA混杂纤维的掺入能有效抑制混凝土爆裂的发生，少量掺入PVA纤维（0.1%）时，即可有效抑制爆裂现象的发生，适量掺入钢纤维（不少于1.0%）能够改善混凝土爆裂现象。在试验范围内，当钢纤维掺量为1.5%、PVA纤维为0.3%和矿粉为10%时，HFHPC试件抗爆裂性能最佳。随着目标温度的升高，HFHPC试件立方体抗压强度下降，在常温至400 ℃时，试件的立方体抗压强度下降幅度较小，在400 ℃后，试件的立方体抗压强度下降幅度明显增大。通过扫描电镜对微观结构观察分析得出，PVA纤维在试件内融化并形成孔道，为试件内部水分的蒸发提供了通道，降低了试件内部蒸汽压力，从而有效抑制了混凝土的爆裂。

In order to investigate the effect of three factors, steel fibre, polyvinyl alcohol (PVA) fibre and slag powder, on the bursting behaviour and cubic compressive strength of steel-PVA hybrid fibre high performance concrete (HFHPC) after high temperature. Orthogonal experimental design for three factors: steel fiber, PVA fiber and slag powder, and high-temperature bursting test as well as cubic compressive strength test, and the microstructure of HFHPC specimens after different temperatures was observed and analysed using scanning electron microscopy (SEM). The results show that the incorporation of steel-PVA hybrid fibre effectively inhibits the occurrence of concrete bursting, and a small amount of PVA fibre (0.1%) can effectively inhibit the bursting phenomenon. An appropriate amount of steel fibre (not less than 1.0%) can improve the concrete bursting phenomenon. Within the test range, the best bursting resistance of HFHPC specimens is achieved when the steel fibre dosage is 1.5%, PVA fibre is 0.3% and slag powder is 10%. The cubic compressive strength of HFHFPC specimens decreases with the increase of the target temperature, and the decrease of the cubic compressive strength of the specimens is relatively small from room temperature to 400 ℃. The decrease of the cubic compressive strength of the specimens increases significantly after 400 ℃. Analysis of the microstructure observation by scanning electron microscopy concludes that the PVA fibres melt and form pores inside the specimen, which provide channels for the evaporation of water inside the specimen and reduce the internal vapour pressure of the specimen, thus effectively inhibiting the bursting of the concrete.