Effect of Mineral Admixtures on Mechanical Properties of High Strength Concrete Made with Locally Available Materials

This paper reports a part of an ongoing experimental laboratory investigation being carried out to evaluate the mechanical properties of concrete made with mineral admixtures and local Jordanian materials. Various percentages of Silica Fume (SF) and Fly Ash (FA) were added at different water/cementitious (w/cm) ratios. Concrete specimens were tested and compared with plain concrete specimens at different ages. Results indicated that compressive as well as flexural strengths increased with mineral admixture incorporation. Optimum replacement percentage is not a constant one but depends on the w/cm ratio of the mix. SF contributed to both short and long-term properties of concrete, whereas, FA showed its beneficial effect in a relatively longer time. Adding of both SF and FA did not increase compressive strength in the short-term, but improvements were noticed in the long-term. Compared with compressive strength, flexural strength of SF concretes has exhibited greater improvements. Relationships between the 28-day flexural and compressive strengths have been developed using statistical methods. It is concluded that local concrete materials, in combination with mineral admixtures, can be utilized in making High Strength Concrete in Jordan and such concrete can be effectively used in structural applications.