4. Dr. Gabriela Bar–Nes

The production of Portland cement for the concrete industry is known to leave an enormous environmental footprint due to the immense amount of natural resources needed to produce billion tons of concrete each year and the massive emissions of carbon dioxide involved. Therefore, the development of supplementary sustainable materials partially or fully replacing the Ordinary Portland Cement (OPC) is essential. Using waste-based materials to replace OPC not only reduces the costs and energy required for the production processes but offers an additional environmental benefit by reducing the waste disposal volumes and overall ecological hazard involved. Therefore, this approach would also provide an efficient, green disposal path for quarry or industrial waste, which currently poses an environmental concern. This lecture will present several studies aiming at the development of building materials using waste materials and quarrying waste. One approach involves the use of dolomite-based quarry-dust (QD) waste material as a filler to Portland cement-based pastes and to Fly-ash based geopolymeric mixtures. Experiments showed that unused QD may be integrated at high replacement rates (up to 40% by weight) in both CEM-I and FA-based systems, showing good and, in some cases, even significant improvement in their engineering properties. An additional approach was the use of local oil shale ash (PAMA Ltd, Israel) as a main component in the development of novel, valuable, building materials. Oil shale ash (OSA) is rich in calcium content and therefore possesses self-cementing properties. Local OSA was used combined with Portland cement to yield products with fair compressive strengths, emphasizing the high potential of OSA waste to be utilized as a new sustainable building material.