Evaluation of internal curing effects on concrete

Rodríguez-Torres, Sergio David | 2019

The objective of the present research was the evaluation of some fresh and hardened-state properties of concretes, in which coarse aggregates were partially replaced by lightweight ones previously saturated, in percentages of 15 % and 25 %. The lightweight aggregates were calcined clays and crushed clay bricks. In parallel, the effect of an internal curing agent composed of superabsorbent polymers (SAP) was evaluated. The properties evaluated in the fresh and hardened-state of concretes with a/c of 0,30 were: slum, air content, density, compression resistance, modulus of elasticity, initial superficial absorption and chlorine resistance. Results showed the efficiency of crushed clay bricks as internal curing, as well as the need for deeper research on the use of the evaluated lightweight aggregate as internal curing aggregate in concrete. Results indicate that the crushed clay bricks and the internal curing agent fulfill the behavior expected, in terms of strength and durability. However, the evaluated lightweight aggregate produces a reduction in the resistance and durability of the concrete. The observed behavior in strength and durability is especially variable for the age of 180 days, compared with conventional concretes.