Solid waste management in developing countries: Reusing of steel slag aggregate in eco-friendly interlocking concrete paving blocks production

The needs to meet the global demand for the conservation of non-renewable resources has necessitated the efforts of finding alternative materials. This current study investigates the beneficial utilization of the crushed waste furnace steel slag as a replacement for natural sand in concrete interlocking paving block units' production for pedestrian and non-traffic applications. A total number of 144 paver samples were cast at replacement percentages of 0, 20, 40, 60, 80 and 100 % by weight of sand using a mix proportion ratio of 1:1.5:3 (cement: sand: granite) at a constant water-cement ratio of 0.5, targeting a strength of 20 MPa at 28 days. Tests carried out include physical characterization of the constituent materials, compressive strength, split tensile strength and water absorption tendency of the hardened H-shaped interlocking pavers. Results showed a significant 15 % increase in the compressive strength at 28-day up to 40 % sand replacement while the tensile strength also increases by 10 % at 28-day up to 20 % sand replacement compared to the control samples before a gradual strength reduction as the percentage replacement increases. The results indicate the possibility of using waste furnace slag for the production of interlocking pavers to promote an eco-friendly and sustainable pavement infrastructure in line with the UN Sustainable Development Goals. (C) 2021 The Author(s). Published by Elsevier Ltd.

Automated summary

This study demonstrates the potential of using waste furnace slag for the production of interlocking pavers as a substitute for natural sand, which can increase the compressive and tensile strength of concrete products at certain replacement percentages. This finding contributes to promoting eco-friendly and sustainable pavement infrastructure.