OBTAINING SELF-COMPACTING CONCRETE USING DEMOLITION WASTE

Abstract

One of the main environmental problems is the disposal or recycling of big volumes of waste materials from construction and / or demolition. One of the most common materials in these residues are waste clay bricks bonded with cement mortar (masonry waste-MW). Only a city as Bogotá, Colombia, produces approximately 15 million cubic meters each year of debris from construction. Therefore the aim of this investigation was the use of grinding masonry waste in the production of  self-compacting  concrete  (SCC)  as  a  replacement  of  cement  at  different  percentages,  ranging  from  10%  to  50%  by weight. The Properties in fresh state of CAC were assessed using the slump flow cone Abrams, L-box and V- funnel. In order to maintain an adequate flow in the CAC was required increasing dosis of superplasticizer when the replacement of Portland cement was greater. There  was  also  an  evaluation  of  mechanical  properties  such  as  compression  strength  and indirect tensile. The best results were obtained with substitution of cement in percentages of 10% and 20%; with higher rates  of  substitution  as  30%  and  50%  there  were  achieved  significant  resistances,  although  they  were  slightly  minors. Based on these experimental evidences, it can be said that the use of masonry waste is promising in the manufacture of self-compacting concrete, especially in the diminishing of costs of production and in the impact on environmental aspects.