RECYCLING STONE-CUTTING WASTE FOR ECO-FRIENDLY KERBSTONE PRODUCTION IN HEBRON, PALESTINE

Abstract

The stone industry in Palestine is a major contributor to the Palestinian national economy, with 153 stone cutting factories in the Hebron region alone. The primary problem lies in the massive environmental challenges caused by this industry along the Hebron valley. Approximately 500 m^3of liquid stone cutting waste (liquid slurry), are disposed of through the sewage system, ultimately ending up in the valley and causing widespread environmental and economic challenges along the Hebron valley. This research investigated the sustainable recycling of liquid slurry as a partial replacement for mixing water in eco-friendly Kerbstones production, reducing the need for costly pre-treatment of liquid slurry. This methodology includes three different levels of liquid slurry/water volumetric replacement ratios, namely 0%, 10%, and 20%, with or without the addition of plasticizer. This yield six concrete matrices were evaluated for mechanical and abrasion resistance at 28 days after 28 days. The observed results showed that 10% LS was the best-performing incorporation level among the three tested levels. The C-10-SP mixture recorded the highest observed combined performance, with a mean compressive strength of 45.3 MPa, flexural strength of 5.72 MPa, and abrasion depth of 2.01 mm. Plasticized mixtures showed higher observed performance for several comparisons, but the limited replication did not permit a statistically conclusive general observed plasticizer response. Using the best-performing tested incorporation level of 10% as the calculation basis, this methodology contributes to a more sustainable environmental and economic approach. On a daily production scale expected to reach a maximum capacity of 1000 m^3 of kerbstones, this approach can incorporate up to 18 m^3 of liquid slurry, yields direct environmental benefits, including a reduction in the annual carbon dioxide emissions of 55.1 tons Economically, switching from traditional disposal to direct recycling reduces annual operating costs by approximately 284000 shekels. Therefore, the recycling system described in this thesis offers acceptable feasibility and may contribute to the adoption of more sustainable environmental solutions related to stone cutting waste.