Avaliação das propriedades do concreto de pós-reativos: um estudo de durabilidade

Abstract

With the advancement of technology and the need to build structures increasingly resistant and slim, new types of concrete have been developed to meet this demand. After conventional concrete, it has been the development the high resistance concrete, high performance concrete, and more recently, the ultra-high performance concrete or reactive powder concrete. The objective of this paper is to determine some properties of reactive powder concrete mainly evaluating its behavior towards the penetration of aggressive agents. It also has been compared to the conventional concrete results, since this is still the most widely used type of concrete. The properties evaluated were: compressive strength, porosity (by injecting air under pressure into the mass of the concrete), and electrical resistivity and total water absorption by capillarity. The results show a great difference of the properties between different types of concrete. It was found that the use of silica fume and quartz powder, according to a better packing of the particles, caused a reduce in the porosity and water absorption of reactive powder concrete in relation to conventional concrete. It was also observed values of electrical resistivity of reactive powder concrete greater than those obtained for conventional concrete. Therefore, this paper presents a characterization of the different properties that influence on the behavior of the penetration of aggressive agents and present different types of concrete in terms of durability demonstrating clearly the benefits of using reactive powder concrete in aggressive environments.