Estudo da caracterização mecânica e retração do concreto autoadensável

Abstract

Self-compacting concrete (SCC), developed in Japan in 1988, is an innovation in the construction industry that eliminates the need for external vibration during the concreting process and fills the forms autonomously. This type of concrete has become a popular option for the execution of monolithic structures, such as concrete walls and prefabricated parts. However, shrinkage is a significant challenge faced when using self-compacting concrete, as this problem can be caused by a number of factors, including plastic, chemical, thermal and hydraulic shrinkage. The aim of this work is to evaluate the behavior of different types of self-compacting concrete using the reference mix commonly used in concrete wall construction. This study will analyze the mechanical behavior and shrinkage of the concrete in the reference mix, as well as its response when fibers and the shrinkage-reducing additive (RR) are added. The tests carried out are: axial compression, diametral compression tensile, modulus of elasticity, absorption, double punching and shrinkage. All the results of these tests were similar, except for shrinkage and immersion. The RR additive proved effective in combating shrinkage, with a 36% improvement compared to the reference mix. The polypropylene fiber, due to its low dosage in the mix and its low modulus of elasticity, did not obtain significant results, but only a 12.48% improvement in combating shrinkage.