Estudo da durabilidade de argamassas alternativas produzidas de resíduos de construção e granito.

Abstract

The preservation of natural resources and search for sustainable development are increase in interest by the researchers with the aim to obtain knowledge of non conventional materials. Among these materials stand out the recycling of residues from civil construction and from granite industry, which are producers of large amount of residues and causing great environmental impacts. The main impediment for the general use of these materials is related to their behavior with the time. To have a confidence in the technological characteristics of a new material and to indicate as a new technology to be used is necessary to know the use conditions and its durability. The aim of this work is to study the durability of the alternative mortar incorporated with residues from civil construction and from granite industry. To quantify the durability of the studied materials, it was made test of natural and accelerated weathering through wetting and drying cycles. The materials were submitted to conditions that simulated their use to evaluate their degradation. The physical and mineralogical properties of the raw materials were analyzed by granulometric size by laser diffraction, specific surface area, Blaine air permeability, chemical analyzes, differential thermo analyzes, thermogravimetric analyzes and X-ray diffraction. Also it was measured the pozolanic activity of the residues according to the Brazilian norms. After it was studied the durability of the mortar by using percentages of substitutions, w/w%, of lime by recycling residue. The amount changed from 30 to 50%. It was measured the influence of these amounts in the simple compression strength. The samples were submitted to natural and accelerated weathering after 28 days of cure in water. In the natural weathering the samples were submitted to 60, 90, 120 and 180 days. To the accelerated weathering, the samples were submitted the 20, 30, 45, 60 and 90 cycles of wetting and drying. The results that the mortars incorporated with residues have pozolanic activity. The natural weathering cause a compromise in the durability of the material after 60 days with a decrease in the mechanical behavior and the best results occur to the sample with 30% and 50% of residue. In the accelerated weathering, the results show indicate the formation of calcium and potassium aluminosilicates that can give an increase in the mechanical behavior, however, it was not observed a compromise in the durability of the material.