Comparative Analysis of Compressive Strength of Concrete with Three Different Chemical Admixtures

Abstract

This study was carried out to evaluate the effect of chemical admixtures on the compressive strength of concrete. All concrete mixes were prepared with a mix ratio of 1:1.5:3, while water to cement (w/c) ratios of 0.39 were adopted. Different concrete mixtures were produced using three chemical admixtures (Fosroc Auramix 300_QCDB-615, Sika Plast 2029 NS BD, and CasTech LRPS 3000.S.) applied at the rate of 0.8% (weight of the cement), during the production process. Laboratory results of the fine aggregate used for the concrete production showed that it was well graded and met international standards. All the concretes were produced and tested in accordance with American Society for Testing and Materials (ASTM) standard procedures. Results indicated that the concrete produced with the chemical admixtures showed better concrete performances both in the fresh and hardened state. After 28 days of casting, concrete produced with Fosroc Auramix 300 QCDB-615 admixture had the best compressive strength (4655 Psi), compared with the compressive strength of the concrete produced with the Sika Plast & CasTech admixture (4438 Psi & 4293Psi), and the control concrete samples that had compressive strength of 4000 Psi. In addition, the fresh concrete produced with chemical admixtures gave a better slump than the fresh concrete produced without any chemical admixture. Likewise, Fosroc Auramix 300 QCDB-615 admixture performs better among the three admixtures used, given a more linear relationship between the slump and water/cement ratio. These results showed the importance of chemical admixtures when higher compressive strength becomes a vital factor in structural construction.