Enhancing durability of plain cement concrete by incorporating GGBS.

With increase in industrialization, quality of air, water and soil is getting deteriorated. Demand for durable structural concrete is increasing to resist aggressive environment. State of Gujarat in India is having more than 1000 km long coastline. The areas surrounding to coastline are suffering from salinity and other issues in soil as well as sulphates and chlorides in water. Cement companies have started to explore use of GGBS to overcome these problems in Gujarat in recent times. Present trend is of use of GGBS by replacing clinker upto 40-50% by the companies. Hence, an attempt has been made to explore potential of using GGBS in concrete upto 60% of OPC replacement for achieving protection to concrete against various durability tests. Durability properties of M25 grade concrete is evaluated in the present study. Three concrete mixes are prepared replacing OPC by 0%, 40% and 60% of GGBS, respectively. Compressive strength of concrete mixes is evaluated after completion of curing of 28 days. Acid, Sulphate & Chloride resistance is measured for concrete mixes for exposure upto duration of 90 days. Acid exposure test results showed higher weight loss and higher reduction in compressive strength for control concrete as compared to that of slag concrete. The sulphate and chloride exposure test results showed that the slag concrete mixes are able to maintain the weight change as well as the compressive strength as compared to that of control concrete. It has been observed from the accelerated corrosion test that with increase in slag content, rate of corrosion decreases for the concrete mixes. Slag concrete performed excellent as compared to that of control concrete for the RCPT. Overall, it can be stated that increase in GGBS dosage has resulted into better performance of concrete with respect to various durability properties attempted in the present investigation.

Author: U.V. Dave, B.R. Sojitra

Section: Concrete

Keywords: OPC, GGBS, chemical attacks, accelerated corrosion, rapid chloride penetration test.