Effects of Water-Cement Ratios on Degradation of High-Water Material During Weathering

High-water material (HWM) is a new cementing material with many excellent properties and is apt to get weathering. The objective of this study is to explore the degradation mechanism of HWM during weathering and the effects of w/c ratios on the weathering process of HWM were explored by laboratory tests. HWM samples of w/c = 3:1 and 6:1 were prepared and conducted to a 10-day indoor weathering test, and microstructure, chemical component, and physical and mechanical characteristics were investigated. The results showed that: The degradation of HWM during weathering is mainly due to the loss of water and carbonization of Ettringite. Free and crystal water loses rapidly and the carbonization reaction of Ettringite occurs and Ettringite crystals are easily corroded by CO2 in air. The degradation of HWM during weathering highly depends on w/c ratio and HWM with a lower w/c ratio has a better weathering resistance, and loses its water and strength easier during weathering. After 10-day weathering, HWM with w/c = 3:1 and 6:1 lost 20% and 70% of strength respectively.