Abstract
Abstract:This paper presents an investigation into the effect of a modified zeolite additive
(PWC) on strength and durability behaviour of concrete. The additive, a blend of
selected alkaloids and zeolite, is commercially available and effectively used in soil
stabilization for road construction. However, its influence on behaviour and
performance for use in concrete has not been explored. In this research, concrete
samples were prepared by incorporating PWC and/or 30% fly ash in the mixes. PWC
was used in proportions of 0.6 %, 0.8%, and 1.0 % of the weight of cement. Concretes
or mortars of 0.5 water/cementitious ratio were subjected to split tensile strength,
compressive strength, oxygen permeability, sorptivity, and porosity tests. Hydration
behaviour of the cementitious systems and the pozzolanic effect of PWC additive
were studied using differential thermal analysis and thermogravimetric analysis.
Results show that PWC is effective in improving concrete strength when used at
optimum proportions found to be between 0.6 % and 1.0 %. Sorptivity property of
concrete was improved with use of PWC regardless of its proportion in the mix, while
permeability of concrete improved only in the presence of 30 % fly ash.