UTILIZATION OF BASALTIC QUARRY DUST AS A PARTIAL REPLACEMENT OF CEMENT IN HOLLOW CONCRETE BLOCK PRODUCTION IN THE CITY OF ADDIS ABABA (THE CASE OF KALITY AGGREGATE PRODUCTION SITE)

Abstract

Crusher dust is a byproduct from crushing of coarse aggregate during quarrying activities. The utilization of this materials as a manufactured sand is controversial due to excessive fine particles in it and the disposal of fine materials is causing environmental problem. On other hand, the use of hollow concrete blocks as a walling material has been increased following the boosting of building construction activity in the country. This resulted in shortage of construction materials, especially the cement, creating price escalation. Furthermore, the sustainability problem related with the production of cement is a major issue of the globe. This research was, therefore, conducted to examine the potential of basaltic crusher dust as partial replacement for Portland pozzolana cement in hollow concrete block production. In doing so, Some units of cement pastes and concrete hollow blocks of different classes, i.e. A, B and C, were produced by partially replacing the cement content with 10%, 20%, 30% and 40% by weight of basaltic crusher dust using vibrating block molding machine. The units without basaltic crusher dust serve as a control. The cement pastes were examined for consistency and setting time, and the blocks produced were tested to determine their compressive strength, water absorption rate and density. Furthermore, the possible cost advantages of using basaltic crusher dust as partial replacement of cement in hollow concrete block were analyzed. The result indicates that the experimental HCB of class A and C surpassed the required standard of compressive strength, water absorption and density specified by the Ethiopian standard ES 596:2001; whereas, the compressive strength of class B fails at 40% cement replacement. It was concluded that concrete hollow blocks of class A and C with up to 40% replacement and class B with up to 30% replacement can be used for load bearing walls and save costs of block with comparable properties