Influência de um aditivo compensador de retração à base de óxido de cálcio supercalcinado nas propriedades do concreto autoadensável

Abstract

Concrete consumption demand of self-compacting concrete is continuously growing due to investments in new infrastructures and upgrades or replacements of old infrastructures in the world. Monitoring the quality and increasing the performance of concrete structures is essential to keep up with this growth. In this work, we explore the effect of adding a commercial over calcined calcium oxide-based compound to a shrinkage-compensating admixture (SCA) on the properties of fresh and hardened concrete, in particular on the shrinkage and curing of self-compacting concrete specimens (SCC). Also, an experimental protocol is proposed for the electrical impedance analysis of concrete samples. Fluidity and compression tests, shrinkage, elastic modulus, impedance spectroscopy, and energy dispersive spectroscopy mapping (EDS) were performed for two compositions and one reference sample. The over calcined calcium oxide-based shrinkage-compensating admixture slightly modifies the concrete properties in the fresh state, mainly the fluidity, but it does not significantly affect the properties in the hardened state of the concrete. [resumo fornecido pelo autor]