Alternative for river sand

Abstract

The need of finding an alternative for river sand arises due to the over exploitation of river sand and its various harmful consequences. The focus of the current study was on offshore sand, which is clearly one of the most viable alternatives for river sand, with respect to availability, ease of extraction, environmental impact and cost. Offshore sand is already used in Sri Lanka mainly for road filling and it is also used for construction in all over the world. A sea survey was conducted in Kaluthara-Benthota sea area and a resource distribution map was plotted. Samples from Muthurajawela offshore sand stick piles were collected and CT content was checked. Offshore sand saturated with sea water has Cl' content around 0.3%, where as if the seawater is gravity drained; it reduced to around the acceptable 0.075%. The action of an average rain fall would be enough to reduce the CT contents to below acceptable levels. However, two other alternatives were also studied in a limited way, namely manufactured sand and quarry dust are quarry products. While quarry dust is merely a by product from the production of course aggregate and tends to be flaky in shape, manufacture sand is actually produced such that a more desirable "rounded cubic" shape is obtained.