Effects of Carbon Thin Film on Low-Heat Cement Hydration, Temperature and Strength of the Wudongde Dam Concrete

Research on the mechanism of carbon thin film (CTF) is a hot issue in the field of concrete materials and is of great significance to the temperature control and crack prevention of concrete structures, but little research has been conducted regarding this issue. In this paper, the composition of CTF and its influence on cement hydration, concrete temperature and strength are studied in the context of the Wudongde (WDD) dam project. Through observations of hand specimens, rock slice identification and X-Ray Fluorescence (XRF) analysis, it was shown that the CTF has the same chemical composition as the limestone component, except for the presence of low-crystalline graphite. Based on hydration testing using TAM Air, it was found that CTF promotes the dissolution of cement and the hydration of C3A in the very early stage but exerts a lowering effect on the second exothermic peak of cement hydration. In addition, the greater the CTF content, the greater the hydration heat release. According to temperature measurements of the Wudongde (WDD) dam, CTF could promote an increase in the maximum temperature of concrete blocks. Finally, compressive strength analysis revealed that the content of CTF was proportional to the compressive strength of concrete specimens and provides a reference for the effect of CTF on the performance of low-heat cement concrete.