Durability indicators of OPC concretes subject to wick action

Abstract

Durability indicators for six OPC concrete mixes were obtained from wick action testing on concrete cylinders placed in water and a sodium chloride solution of concentration similar to sea water. Although 49 weeks of exposure to wick action in the salt solution was not sufficient to cause appreciable deterioration in the concretes, indirect durability indicators such as moisture transport phenomena and chloride ingress measurements were used to distinguish between the different concrete mixes. Increases in the water:cement ratio from 0·4, through 0·6, to 0·8 caused significant reductions in durability properties. An increase in cement content from 400 to 600 kg/m3 also impaired durability. However, the inclusion of 0·6% (by volume) chopped coir fibre to the control mix (w/c = 0·4, cement content = 400kg/m3) reduced durability only marginally. On the other hand, the inclusion of ultrafine gneissic quarry dust as a partial fine aggregate replacement in the control mix improved the durability indicators somewhat.