Effect of internal curing on properties of high strength concrete

Abstract: Reducing the environmental impact caused by the concrete industry has been a major concern in recent years, since Portland cement production consumes about 13% of the world's industrial energy and is responsible for approximately 7% of CO2 global emissions. In the pursuit of eco-friendly civil construction, several alternatives have been proposed to reduce environmental impacts, through the reuse of industrial wastes, recycled materials, or wastes from construction itself. One alternative to solve these problems is to use the industrial by-products as mineral admixture to replace the OPC in the SCC. Fly ash (FA), Ground granulated blast furnace slag (GGBFS) are two types of mineral admixtures frequently using in the SCC. Utilizing FA, GGBFS for the production of the SCC can not only reduce total material costs of the SCC, but also result in considerable benefits to the environment. In addition, the use of FA, GGBFS in the SCC has a unique and distinctive effect on the properties of the SCC. Self-compacting Concrete (SCC) is a highly flowable concrete that consolidates with its own weight, has the capability to be placed and leveled without the need of vibration and fills into structural members of highly congested reinforcement. Owing to its self-consolidating ability, no vibration is required which saves time and labor. In addition, since no vibration is required, noise pollution is mostly eliminated at construction sites, thus SCC has an advantage especially when concreting at night in residential areas. In this study, OPC used as binders, and FA, slag, and forest industry waste ash were used as mineral admixture. Expanded perlite was also used as fine aggregate for internal curing. The 100 x 100 x100 mm sized poured concrete samples were kept in two different environments as water curing and laboratory curing, after curing, physical, mechanical and durability properties of the samples were determined. Internal curing created by expanded perlite was increased the compressive strength of the SCC for 3 and 7 days, determined that laboratory cure was effective early age and also water cure is effective in later ages. It has been observed that mineral additives used in high fineness and high volume (60%) increase mechanical strength and freeze-thaw resistance.