In this paper, wet shotcrete spraying experiments were carried out under different temperature and humidity conditions with different dosage of metakaolin (MK) and different length of polyvinyl alcohol fiber (PVA fiber). And the influence of different content of metakaolin and different length of PVA fiber on the compressive strength of tidal shotcrete under different curing conditions was explored. The results show that the compressive strength of shotcrete increases first and then decreases with the increase of MK content and PVA fiber length under the curing condition of normal temperature and constant humidity. However, under the curing condition of high temperature and humidity, the compressive strength of shotcrete tended to increase with the increase of MK content. Under the condition of high temperature and high humidity curing, the compressive strength of shotcrete is lower than that of shotcrete under normal temperature and constant humidity curing. This study can provide theoretical support for the application of sprayed concrete in different environments

Keywords: High temperature and high humidity, Shotcrete, Metakaolin, PVA fiber, Compressive strength