Acceleration of Hardening Kinetics of SCC

Shortening the hardening time of SCC allows the precast concrete industry to respond to its challenge of productivity and extend the scope of application of these materials. Indeed, reducing the elapsed time between mixing fresh concrete and demoulding the concrete products represents a key factor for a faster rotation of the equipment and reduces the global cost of production. The results of the study show that it is possible to accelerate significantly the hardening kinetics of SCC. Applying an optimized thermal treatment on SCC mixture based on conventional constituents and suitable admixtures enables one to produce concrete that stays workable for 30 minutes and reaches compressive strength up to 25 MPa after 4 hours of curing and more than 80 MPa at 28 days. The influence of the thermal treatment, the use of hardening accelerator and ultrafine particles were evaluated.