EXPERIMENTAL INVESTIGATION ON THE MECHANICAL STRENGTH AND DURABILITY OF HIGH-PERFORMANCE CONCRETE INCORPORATING COPPER SLAG AS A FINE AGGREGATE REPLACEMENT

1.      Copper slag can be effectively utilized as a replacement for natural fine aggregate in M50 high-performance concrete. 2.      The workability of fresh concrete was influenced by the increasing copper slag content. The change in slump is attributed primarily to the physical characteristics and water absorption behaviour of copper slag. 3.      Copper slag replacement significantly influenced the compressive strength of HPC. Suitable replacement levels provided satisfactory strength development, while excessive replacement may result in reduced strength. 4.      The splitting tensile strength was also affected by the copper slag content and generally followed the trend observed in compressive strength. 5.      Flexural strength demonstrated that suitable copper slag incorporation can maintain satisfactory bending performance of high-performance concrete. 6.      UPV results provided a useful non-destructive indication of the internal quality and uniformity of the concrete and supported the interpretation of the mechanical strength results. 7.      Water absorption and sorptivity were influenced by the copper slag replacement level. Suitable replacement levels can reduce water ingress by improving the packing characteristics of the concrete. 8.      The RCPT results demonstrated that copper slag replacement can influence resistance to chloride ion penetration. The suitability of a replacement level should be assessed based on the charge passed relative to the control concrete. 9.      Sulphate resistance was affected by copper slag incorporation, and an appropriate replacement level can provide satisfactory resistance under sulphate exposure. 10.   The overall results indicate that the performance of copper-slag concrete depends strongly on the replacement percentage. Therefore, complete replacement of natural fine aggregate should not automatically be considered optimum. 11.   The optimum copper slag content should be selected based on the combined mechanical and durability-related performance rather than on a single property. 12.   The study demonstrates that copper slag has potential as a sustainable fine aggregate replacement in high-performance concrete, thereby reducing the consumption of natural sand and promoting beneficial utilization of an industrial by-product.

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