Assessment of self-healing and durability parameters of concretes incorporating crystalline admixtures and Portland Limestone Cement

The repair of concrete structures damaged by water or water borne chemicals is estimated to cost billions of dollars annually worldwide. However, the solutions that can make concrete structures more sustainable and durable, are limited. The use of crystalline admixtures (CA) has a potential of improving the durability and reducing permeability of concrete structures especially those exposed to corrosive environments. This paper presents various investigations on the influence of crystalline admixtures on the strength, self-healing, and durability characteristics of concretes with two different cement types (Ordinary Portland Cement [OPC] and Portland Limestone Cement [PLC]). Test methods include the rapid chloride permeability (RCP), surface/bulk electrical resistivity and water permeability tests, self-healing test, compressive strength test and salt ponding test. The results indicate that the water permeability coefficient decreased by 3 times whereas the self-healing ratio increased by a higher rate by adding crystalline admixtures into the concrete mix. This paper presents empirical equations to correlate resistivity, total charge passed, or water permeability with each other. Further, the correlation between the surface and bulk resistivity is strong and the evidence from self-healing test suggests faster sealing of crack widths up to 250 mu m for CA treated specimens.