Volume :

6

Issue :

1

Abstract :

Coastal areas are getting populated day by day with lots of hotels and residential buildings considering the tourists attraction. But non availability of plain water for curing and seawater intrusion in coastal regions has a great impact on the strength of concrete structures in coastal regions. Again recycled aggregates of demolished concrete are being wasted without any beneficial use. These recycled aggregate can be reused in concrete construction in the coastal regions if it is possible to gain a rational percentage of strength after some specified curing periods. So to study the optimum percentage of recycled aggregate on recycled concrete in salt environment, three types of variables are used in this study. Percentage of recycled aggregate, curing period and concentration of saline water are those three variables involved. For this study 3 various percentage of recycled aggregate used in concrete casting which are 30%, 40% and 50% recycled aggregate. For the 3 different types of aggregate samples 3 different types of concrete has been cast in 100 mm cube specimen and cured in 3 different concentrations of 1N, 3N and 5N curing water. The specimens are then tested for compressive strength for curing periods of 28 days, 60 days and 90 days. The results of compressive strength test of these recycled concrete are then compared with the compressive strength of plain concrete with 0% recycled aggregate cured in plain water by considering it as a standard. From the investigation work it has been found that concrete cast with 30% recycled aggregate achieves 95.4% compressive strength for 28 days curing in 1N concentration of saline water, which is comparatively higher among other recycled concrete used here. Percentage of strength achievement are higher for 28 days curing but it starts to decrease with the increase of curing period in saline water compared to the strength of concrete cured in plain water. Compressive strength decreases with increasing percentage of recycled aggregate and increasing concentration of salinity. Thus 30% can be said to be the optimum percentage of recycled aggregate in this study which is accessible to use in marine structures only when curing in high saline water can be avoided as much as possible.