Experimental Study on Activation Energy of Typical Hydraulic Concrete
Yaoying Huang, Yong Zhou, Shifa Xia, Xiaofeng Xu
Appears on pages(s):
activation energy model; curing temperature; fly ash content; hydraulic concrete; Kim’s method
Existing methods to determine the activation energy of hydraulic concrete generally assume that it is constant, thereby neglecting the fact that it depends on curing temperature and fly ash content. To clarify this issue, this study experimentally investigates the activation energy of typical hydraulic concrete at different curing temperatures (5, 20, and 40°C) and fly ash contents (0, 15, and 35%) and obtains the activation energy of typical hydraulic concrete through a modified optimization algorithm based on Kim’s method. By analyzing the activation energy as a function of either curing temperature or fly ash content, a comprehensive model is developed to accurately predict the activation energy of typical hydraulic concrete for different curing temperatures and fly ash contents. The experiments reveal that the ratio of the hydraulic-concrete activation energy to the gas constant at 5, 20, and 40°C is 4764 to 5251, 4309 to 4874, and 3897 to 4575 K when the fly ash content is 0%, 15%, and 35%, respectively. For a given
fly ash content, the hydraulic-concrete activation energy increases as a power law in temperature and, at a given temperature, it decreases quadratically with increasing fly ash content. The results of the proposed model of the activation energy of typical hydraulic concrete are consistent with the experimental results for different curing temperatures and fly ash contents.