JOURNAL OF ENGINEERING RESEARCH AND TECHNOLOGY, VOLUME 5, ISSUE 3, SEPTEMBER 2018 41 Incorporation of waste glass and bottom ash in concrete construction Mohammed H. Arafa Associate Professor of Civil Engineering, Islamic University of Gaza, Palestine. Abstract This research investigated the effect of incorporating waste glass powder and raw bottom ash in concrete construction. Laboratory work was designed to identify the performance of concrete mixes using waste glass powder and raw bottom-ash as a partial substitute of cement. The performance of the prepared mixes was obtained in terms of workability, compressive strength. The first series of concrete mixes were prepared with 10%, 20% and 30% glass powder as a replacement of the cement content. The cement content of the second series were replaced with 10%, 15% and 20% raw bottom-ash. Further, a third series were carried out having 20 % of cement content replaced by 10% of glass powder and 10% of raw bottom ash. Incorporation of glass powder or/and raw bottom-ash partially replacing cement content in concrete indicated a significant improvement in slump values. The ultimate compressive strength of 10% replacement of cement by glass powder showed the optimum content in which the strength was higher than the control mix. However, Incorporation of raw bottom-ash in concrete as a partial substitution of cement showed decrease in strength compared with the control mix. Index Terms— Concrete, Glass Powder, Bottom Ash, Slump, Compressive strength. 1- INTRODUCTION The Gaza Strip suffers from scarcity of land, where about two million inhabitants live in an area of not more than 360 km2. This resulted in very limited areas available for landfills making disposing solid wastes is a real issue in the Gaza Strip. Further, the flow of construction materials into the Gaza Strip, such as cement, is a very complicated process. This situation pushed the researchers to optimize solid waste recovery to reduce the solid waste quantities going to the current landfills. Glass waste and raw bottom ash represent materials of solid waste compositions that could be utilized as a cement- replacing material due to its pozzolanic reaction. The quantities of waste glass in Gaza Strip have been increasing significantly without being recycled, increasing the risk to public health due to the scarcity of land area. A study conducted by United Nation Development Program in 2012 [1] showed that Gaza Strip produced about 37 ton per day of waste glass in 2012, anticipating this quantity to reach 72 ton per day in 2040. Using waste glass in construction is one of the potential areas to both enhance the performance of concrete and to reduce the adverse social and environmental effects of disposing such solid wastes. Several studies showed that glass has a chemical composition that can be classified as cementitious materials that can be partially replace cement content in concrete mixes [2-5]. Grounding and milling of waste glass to micro sizes can improve the pozzolanic reaction between glass composition and the cement hydrates resulting in the production of calcium silicates hydrates [6-9]. Researchers replaced waste glass powder with a varying percent of cement content used in concrete mixes [4, 8-11]. They replaced the cement content by a wide range of glass powder contents ranging from 10% to 30 %. The effect of adding waste glass powder was studied on various mechanical properties of concrete, such as workability, compressive strength, flexural strength, tensile strength, etc. Due to the slow pozzolanic reaction between silicic acid available in waste glass powder (WGP) and the cement hydrates, the improvement in mechanical properties of the concrete samples containing WGP was observed at higher concrete ages [4]. However, Rashad [7] reviewed past researches conducted on glass concrete and indicated that these researches were not conclusive in terms of workability and strength; the chloride resistance of glass concrete was similar to that of the control sample. Studies were conducted to investigate the potential of using glass culets as aggregates, fine or/and [4, 7, 11-13]. The results of these studies indicated the possibility of replacing natural aggregates with waste. However, the alkali-silica reaction and deleterious chemical constituents should be considered. Aggarwal, et al. [14] and Andrade, et al. [15] studied the effect of use of bottom ash as a replacement of fine aggregates. The study found that the strength development for various percentages (0-50%) replacement of fine aggregates with bottom ash can easily be equated to the strength development of normal concrete at various ages. Rafieizonooz, et al. [16] investigate concrete mixes by replacement of sand with bottom ash waste and cement with fly ash. Concrete specimens were prepared incorporating 0, 20, 50, 75 and 100% of bottom ash replacing sand and 20% of coal fly ash by mass, as a substitute for Ordinary Portland cement. The pozzolanic properties of a coal combustion bottom ash were investigated by [17]. Plain pastes containing equal amounts of calcium hydroxide and bottom ash were prepared and analyzed at different ages for their strength and the