Experimental Investigation of Self Healing Behavior of Concrete using Silica Fume and GGBFS as Mineral Admixtures

The process of self-healing of concrete has been gaining momentum nowadays due to increased deterioration of concrete structures subjected to adverse environmental conditions. Admixtures like silica fume and ground granulated blast furnace slag is one of the self healing agents being experimented recently. The method of usage of Silica fume and ggbfs, the waste derivatives from coal and steel industries, strength and durability testing of these mixes for achieving the self healing property has been presented. The effects of self-healing on normal concrete by adding small amounts of GGBFS and silica fume to concrete is studied. For this purpose, silica fume is added to concrete at percent of 0%, 2.5%, 5%, 7.5%, 10%, 12.5% and cement has been replaced with GGBFS by 35% and 55% respectively. The adopted water binder ratio for silica fume and GGBFS mixes is 0.45. M30 mix design is being done as per the Indian Standard Code IS: 10262-1982. The specimens are first tested for compressive strength at 28 days, then 70% and 90% of the compressive load is applied to another set of specimens to generate microcracks for studying the durability properties of the specimens. The strength properties of concrete specimens made using silica fume and GGBFS are tested for compressive strength and the durability properties are studied using sorptivity index test. The pre loaded specimens are cured for 28 days and then compressive strength tests and sorptivity index measurements are being made at an interval of 14 days. The test results indicated that self healing property can be achieved using silica fume and GGBFS as mineral admixtures as well as the use of these pozzaalonic materials increased the compressive strength values also.