| dc.description.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. | en_US |
