Placement of Low Carbon Concrete (LCC) during harsh winter demands the rational selection of curing techniques to prevent low strength gain and early surface cracking. Nonetheless, hardening of LCC in cold climate along with its thermal curing by heating cables has not been widely addressed. In response, this research integrates testing and modelling to assess LCC winter cast. Six mixes were studied, including Portland Cement (PC), Volcanic Pozzolan (VP), Ground Granulated Blast Furnace Slag (GGBFS) and Limestone Filler (LF) as binders, along with superplasticizer and Air-Entrainment to improve their performance. The compressive and tensile strengths were tested at different ages and bath curing temperatures. Moreover, isothermal and semi-adiabatic calorimetries were used to evaluate the heat development of the concretes. The maturity, strength, heat and cross-over thermal damage were then calibrated for each mix. Using the material models, simulations of winter cast, including insulation and heating cables, were performed for semi-massive and massive concrete ground slabs. Furthermore, the surface cracking risk was assessed by a new index based on a maturity and strength dependent maximum temperature difference. The results show that including the activation energy maturity dependence is necessary to precisely predict the temperature development of the concretes. Moreover, it was found that the PC+VP+LF binder produces more heat during the hydration and has a higher activation energy, which is beneficial for winter cast of semi-massive elements. In addition, the inclusion of heating cables proved to be feasible for controlling the surface cracking risk of massive concrete elements containing GGBFS.
Prieto et al. (Mon,) studied this question.