The aim of this research is to study the effects of surfactant on workability, compressive strength and density of concrete containing para rubber latex as a mix ingredient. Concrete mix proportion of control concrete is designed by selecting compressive strength of 240 ksc and slump between 7.5-12.5 cm as requirements. The mix proportion of concrete is separated in to 2 groups. The first group, the para rubber latex is used as a partial water replacement in the control concrete. The replacement ratios are 0.5, 1.0, 1.5 and 2.0 by weight of water, respectively. For the second group, the surfactant of 5 percent by weight of para rubber latex is used as the latex replacement for all mixtures in the first group. The slump, compressive strength, and density of all mixtures are investigated at the ages of 7, 14 and 28 days, respectively. From the results, it is found that the para rubber latex concrete at the replacement ratios of 0.5 and 1.0 have a similar 28-day compressive strength to the control one which of about 340 ksc. The higher para rubber latex content, the lower compressive strength. In addition, it is found that the surfactant results in dramatical
compressive strength reduction in the latex concrete. Especially, for the concretes those have latex ratios of 1.5 and 2.0 percent, the compressive strength reduction as high as 32 and 52 percent is observed while comparing to the control concrete, respectively. The density of the control concrete and the latex concrete without surfactant is similar which the value is placed during 2.44 - 2.50 g/cm3. Adding the surfactant results in decreasing of the density. For example, the mixture containing 2.0 percent of para rubber latex has the density of 2 . 1 5 g/cm3. It could be
mentioned that the weight also decrease for about 13 percent since the volume is fixed. Even though the surfactant results in lower compressive strength, dramatically, but the weight is lighter while workability is higher. Hence, this kind of concrete would suit very well to a work that require not that much high compressive strength but the light weight and high workability are more serious such as light-weight concrete wall instead of the traditional masonry wall.
