Ensuring adequate durability of mass concrete requires controlling its early-age thermal cracking risk. For this purpose, proper curing techniques must be rationally selected based on concrete’s temperature, stress and strength developments. Hence, understanding the evolution of young concrete strength, heat of hydration and basic creep, is mandatory. Moreover, the decarbonization of the construction industry requires increasing the knowledge on hardening Low Carbon Concrete (LCC). In Sweden, interest exists on testing the early-age properties of modern LCC based on Volcanic Pozzolan (VP), Limestone Filler (LF) or Ground Granulated Blast Furnace Slag (GGBFS). Additionally, the existing material models must be evaluated and modified if required. 

In response, this study tested and modelled the strength, heat, temperature and basic creep of hardening LCC containing GGBFS, VP and LF. In total ten concrete mixes were studied, including reference Portland Cement Concrete mixes for comparison. All mixes compressive and tensile strength developments were tested at various ages and bath curing temperatures. The heat of hydration was tested using semi-adiabatic and isothermal calorimetries. In addition, the compressive basic creep at different loading ages was also tested. Novel formulations for the maturity, strength, heat and basic compliance, were proposed as improvements to those currently used in Sweden. Then, the potential of the studied LCC for the winter cast of a ground slab was numerically evaluated, considering insulating formwork and heating cables as control measures. For this purpose, simulations of the temperature, maturity and strength fields were combined to a novel surface cracking risk index proposal. 

The results show that the GGBFS mitigates the strength reduction due to thermal-damage and promotes a better strength gain under cold curing. The VP was found increase the heat generation, which can be beneficial for winter cast under controlled conditions. Regarding the basic creep, the GGBFS increased the compliance at early loading ages but reduced its value at later loading ages. Differently, the VP increased the instantaneous compliance but reduced the creep rate. On the modelling, the tensile strength model proposed here was found more accurate than the Swedish and fib Model Code proposals. Also, the heat model proposed here remarkably performed in predicting the heat flow kinetics of concretes with extended dormant periods. Moreover, for the maturity, the novel aging activation energy formulation proposed here, was found beneficial to transform the heat measured in the semi-adiabatic test to isothermal conditions. In addition, the basic compliance model proposed here, based on the solidification theory, was found to provide the best fitting for the LCC studied here. Finally, the winter cast simulations showed the potential of the heating cables in control the early risk of surface cracking on VP based concrete.