Slaked Lime and Fly Ash Cement Mix for Application in Marine Environments

Abstract

This thesis aims to examine the viability of using a Calcium hydroxide (slaked lime) and fly ash mix as a replacement for Portland Cement to produce a concrete mix that is more durable in marine environments and more environmentally sustainable. Compressive strength test and the Brazilian splitting test were used to determine the compressive strength and the tensile strength of the slaked lime and fly ash samples. The effect of curing temperature and of using sea water as the mix water on the strength and stiffness of the experimental samples was also tested. To asses durability, the samples underwent wet and dry cycling followed by compressive strength test to determine whether there was any strength loss due to environmental weathering. The static modulus and the dynamic modulus of the samples were also measured to determine the stiffness of these samples compared to control samples prepared with Portland cement. The fly ash and slake lime samples had significantly lower compressive strength compared to Portland cement at 15, 28, and 56 days. However, the samples that were hydrated using sea water had statistically significant higher compressive strength compared to those hydrated using tap water.