Copper slag as construction material

This report evaluates the effect of copper slag as fine aggregate substitution and copper slag-marine clay composition as coarse aggregate substitution in a concrete mix. The needs to look for alternative materials as sand replacement have become increasingly important due to its high cost. Copper slag, which is a by-product of copper ore refinery; have been chosen as both fine and coarse aggregates substitution. The toxicity characterisation of the spent copper slag is also evaluated to determine its leaching ability. The compressive strength of the concrete with varying copper slag content is studied and assessed to determine the optimum content of copper slag replacement. The test was carried out on 5 different mix proportions at 25% increment of copper slag content by weight. Results show a reduction in the concrete compressive strength for fine aggregate substitution. This was due to excess water built up which resulted in a porous concrete. Where else for copper slag-marine clay composition substitution, the addition of copper slag increases the concrete compressive strength. The evaluation of the toxicity characteristic of the copper slag using TCLP test indicates low leaching ability of the copper slag. A conclusion was reached that the optimum copper slag substitution of up to 10% is feasible in fine aggregate replacement while keeping the reduction in compressive strength within an insignificant limit of 5%. In the case for copper slag-marine clay composition as coarse aggregate replacement, the optimum copper slag substitution should be of 95% and higher to keep the compressive strength within the limit of 10%. The poor leaching ability of copper slag make it suitable to be used as a construction material without having a significant environmental impact.Bachelor of Engineering (Environmental Engineering