Abstract

In this work, the influence of waterproofing admixture of stearate type on the
water reduction of concrete mix (1:2:4) for a given workability, (50+5)mm slump was
investigated. Results indicated that this admixture has a little influence on the water
reduction of concrete. Therefore this admixture cannot be considered as a water
reducer since it does not conform with the requirements of type (A) admixture in
accordance with (ASTM-C494-98 Type A)[1].
The same influence on the compressive strength of concrete (fcu) at various ages
(7,28,60 and 90) days was studied. Results showed that the use of this admixture at
recommended dose specified by the manufacturer has no significant effect on the
compressive strength of concrete. On the other hand, overdoses of this admixture lead
to a considerable reduction in the compressive strength.
The efficiency of this admixture at different doses in reducing the total water
absorption of concrete and the absorption of water by the capillary action was also
examined. Results revealed that this admixture is not effective in reducing the water
absorption with all doses used in this work and at different ages compared with
reference mix without admixture.