Relaciones preliminares para la definición de los valores máximos de absorción en unidades de mampostería de concreto

Abstract

This research is intended to demonstrate that aggregates have an important influence on density and absorption of concrete masonry units. This fact is not considered in the concrete masonry national standard INTE 06-03-01-07. Standards of other countries define the absorption according to density and compressive strength of the units. Higher absorptions are registered for blocks made of lighter weight aggregates, due to its greater absorption. Three sources of aggregates with different unit weight and absorption were selected for this research. They were used to design dry concrete mixtures in the laboratory and manufacturing cubes to establish the relationship between absorption and density. In addition, the compressive strength, bond and permeability were evaluated. The cubic specimens of 15cm per side were built using a vibratory hammer to simulate the industrial process of vibro compaction with which the hollow blocks are produced. The absorption of concrete cubes has an inverse linear relationship with its corresponding oven dry density. Keeping the same amount of cement, cubes made with more porous and absorbent aggregates, presented lower densities and resistance, as it happens with higher absorptions and highly permeable concretes.