The mechanical properties of concrete exposed to harsh and complex environments of plateaus at early ages

The independently designed walk-in concrete low-pressure forming chamber and complex environment simulation chamber were employed to more accurately investigate the evolution of mechanical properties of concrete under the complex environment of the plateau. The quantitative comparison of the differences in the impact of each environmental factor on performance under complex coupled environments was conducted using two methods: grey correlation analysis and relative strength method. Meanwhile, the hydration and pore structure of concrete under the complex environment of plateau were studied by TG analysis and MIP analysis. The results showed that the high-altitude complex environment has a significant deterioration effect on the mechanical properties of concrete, mainly due to the decrease in the degree of hydration and pore structure deterioration. The environmental humidity and temperature difference are the main factors affecting the mechanical properties, and the complex environment has a more significant effect on the flexural strength of concrete than the compressive strength of concrete.