La microestructura de los prefabricados de concreto

Abstract

Dried vibro-compacted concrete is a material that because of its characteristics of fast unmolding enables the elaboration of a wide variety of prefabricated products such as: blocks, bricks, pipes, among others. There are many studies on the mechanical characteristics of these elements; nevertheless, there are few studies even at an international level, where these characteristics are co-related with the internal structure of the material and the reasons for the performance. This article presents the results of a study on vibro-compacted dry concretes for concrete bricks, having in mind the mechanical resistance and its co-relation with the micro-structure. Three mixtures were used (two of dry concrete and one of conventional concrete) and the results are compared in their mechanical performance, micro-structure, and porosity. The study for porosity distribution is carried out through mercury porosimetry and the internal structure of the material is done by means of SEM scanning electronic microscopy. The results show the infl uence of micro-fissures in the mechanical resistance and why a product such as brick, with a minor dose of cement that a conventional concrete, has a good mechanical performance.