DEMOLITION AGGREGATE CONCRETE: MODELING AND OPTIMIZATION OF SOME SHORT TERM PROPERTIES

Building waste becamea serious problem that forces the researchers and professionals to focus on its control. For this purpose, sustainable waste management strategies have been implanted to provide effective and efficientplans for waste collection, diversion and disposal, as well as its reusing.The recent work deals with using demolishing concrete waste as coarse aggregate in concrete for the purpose of reduction the natural resource exploitation and associated costs, as well as minimization waste landfill. A 2-operating parameter central composite design (with 2*2=4 factorial points, 2*2 star-points and 2 repetitions of central point) was adopted to optimize and model the impact of demolition aggregate content (8.6-86.4) wt.%, and water/cement ratio (0.43-0.57) for concrete contain demolishing components as coarse aggregate on compressive strength and density. Water absorption characteristics were also investigated. Conventional concrete specimens were prepared and tested for comparison purposes. The results obtained confirmed that the incorporation of the demolition aggregate resulted in decreasing concrete density and water absorption capacity. The model analysis results approved that concrete with lower density and water absorption, and superior compressive strength of 49.70MPa could be manufacturedusing demolishing concrete as coarse aggregate up to 49.3 (wt. %) atwater/cement ratio 0.49