Influence of Ground Granulated Blast Furnace Slag as Cement Replacement on Some Properties of Paste and Concrete Mixes

Abstract

Portland cement, already being a very expensive material constitutes a substantial part of the total construction cost of any project and the situation has further aggravated by the energy crisis, which has further increased the cost of production of Portland cement. Therefore, it is of current importance for the country to explore and develop cementing materials cheaper than Portland cement. This research, focus on investigating Physical and Chemical properties of Portland cement with partial replacement with Ground Granulated Blast furnace Slag (GGBS), such properties are compressive strength, normal consistency, setting times of neat cement mixes (control) and partial replacement of cement with GGBS levels of 20, 40, 60 and 80%, and the main focus to find the optimum percentage of GGBS that gives the greater compressive strengths improvements of concrete. Ground Granulated Blast furnace Slag was collected from Steel Mills Misurata (Libya) and pulverized to a very fine degree.

Concrete of target mean strength 50MPa were produced to determine the compressive strength development under standard curing conditions (200 C). The tests results of normal consistency, setting times showed that the higher the percentage of the GGBS reduce the needed percentage of the water and as the percentage of GGBS increase the initial and final setting time decrease. The strength development appears to be similar to Portland cement concrete strength at all ages for 20% GGBS concrete only, For the concretes with 40, 60 and 80% GGBS the compressive strength was lower than the control concrete during all ages.

GGBS collected from Steel Mills Misurata (Libya), better of it is used as aggregate and not as a binder component in cement manufacture.