EFFECT OF REPLACEMENT OF NATURAL SAND WITH BLASTED COPPER SLAG ON MORTARS PHYSICAL AND MECHANICAL PROPERTIES

Abstract

Environmental preservation is a widely discussed topic throughout society, due to heavy reliance on natural resources for survival on the planet. Rational use of raw materials and their proper disposal are on the agenda of the productive sectors’ major concerns. This work aimed toevaluate the feasibility of application of copper slag waste, after being used as an abrasive material, coming to be called blasted copper slag. It was intended to replace sand to blasted copper slag in mortars, into two fractions, named fine and coarse blasted slag sand, according to the number of times that were used in the abrasive process. Four mixtures were produced, for each type of blasted slag, with levels of 25%, 50%, 75% and 100% of replacement to natural sand, in addition to the reference mortar. The consistence of fresh mortars was measured by the flow table test and the spreading range was fixed for 270 ± 20 mm. Physical and mechanical tests were performed with produced mortars. Mortars with blasted copper slag, both fine and coarse slag, demanded lower water/binders ratio to achieve the desired spreading, compared to the reference mixture. Mechanical tests showed important performance reductions in compression strength of the mortars with fine blasted slag, both in relation to the reference mortar, and when compared to mortars with same replacement content of natural sand by coarse blasted slag. It could be concluded that, for levels between 25 and 50% of natural aggregate replacement by coarse blasted slag, there is feasibility of most mortarapplication, since there are not required high levels of strength and stiffness.