| dc.description.abstract | This study was carried out to evaluate the effect of chemical admixtures on the
compressive strength of concretes. The concretes were produced with the
concrete
mix ratio of 1:1.5:3, while water to cement (w/c) ratios of 0.46 were adopted.
Different concrete mixtures were produced using two chemical admixtures (Dr.
fixit and Super Strength) applied at the rate of 1%, 2%, 3%, 4% , 5% 6% , and
9% (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 met international standards. All the concretes were produced and tested
in accordance to 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 Dr. fixit admixture had
the best compressive strength (24 MPa); compared with the compressive
strength of the concrete produced with the Super strength admixture (26 MPa),
and the control concrete samples that had compressive strength of 26 MPa. In
addition, the fresh concrete produced with chemical admixtures gave a better
slump than the fresh concrete produced without any chemical admixture.
Likewise, Super strength admixture performs better among the two 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 |
