Development of Sustainable Hollow Concrete Block From New Blended Cement and Binary Aggregate the Case of Adama Town Ethiopia

Abstract

ABSTRACT newlineHollow concrete block (HCB) is a widely applied wailing material in Ethiopian newlinehousing construction; in Adama town of Ethiopia conventional HCB is newlinemanufactured from Ordinary Portland cement (OPC) or Portland Pozzolana cement newline(PPC) and unprocessed pumice aggregate. OPC and PPC cement types are made newlinefrom 95% and 67% of clinker, respectively. And although clinker production is an newlineenergy-intensive, expensive and polluting process Ethiopian cement industries use newlineimported fossil fuels for clinker production adding more cost and pollution in newlinecement production. This makes the use of OPC or PPC for HCB production more newlinecostly and less eco-friendly. Moreover, local HCB producers in Adama townEthiopia newlinedominantly newlineuse newlineunprocessed newlinepumice newlineaggregate newlinefor newlinethe newline newlineHCB production, newlinethis significantly affects the strength of blocks. Hence, the research in the newlinedissertation work aimed to develop a new sustainable HCB from new blended newlinecement (with a reduced clinker content) and binary aggregate; the new HCB had an newlineimproved engineering, environmental, and economic performances. And those newlineperformances were assessed through experimental and analytical research methods. newlineThe experimental work was conducted in two phases; in the first phase, appropriate newlineinput ratio for the binary aggregates was determined through a trial blending and newlinetesting procedures. Trial aggregate blends were suggested which were used for newlinemaking concrete cube with a constant cement to aggregate ratio, where the newlinecompressive strength of cubes was tested at 28 days. As per the cube s compressive newlinestrength test result, a trial blended aggregate made with a mix of 60% pumice and newline40% scoria (P60-S40) was found to have maximum compressive strength. This newlineblend was approved as a binary aggregate that could be used for HCB production newlineusing the new blended cement. In the second phase of the experimental study, four newlinetrial blended cements were suggested with varying percentage of OPC, powder of newlinevolcanic clinker (VCP), pumice powder (PP), and limestone powder (LSP). And newlinethose fo