Sandstone wastes as aggregate and its usefulness in cement concrete - A comprehensive review

Concrete production has a lot of environmental impacts causing damage to the most fertile layer of the earth. Cement industry often uses unethical methods in obtaining resources by breaking river stones from the most alluring areas of the world for the production of cement concrete. Due to various environmental hazards associated with cement concrete production industries, most of the government re-forces and subsides the use of cement and also encourages to find a sustainable replacement material for the manufacture of cement concrete. Sandstones are a type of sedimentary rock which is composed of silt-sized minerals, rock grains and clay components. Some of the minerals like quartz and feldspar are the most occurred in earth surface and are found in sandstones. Since sandstones are highly porous when compared to magmatic rocks, they allow water to percolate and form aquifers and petroleum reservoirs. Even though sandstones were widely used in historical constructions around the globe, at present the use of such sedimentary rocks are not traditional in the field of building technology. There are many types of sandstones occurring in earth's surface and can be classified based on their elemental composition, clay content and sometimes based on their colour. Also, mining and quarrying generate a lot of these sandstone wastes which leads to excessive dumping without any utilisation. Although sandstones are a weaker type of aggregates that can be used in concrete, some of the studies have utilised them efficiently depending on the output needed for the use of such sedimentary materials. This paper presents the overview on the possible use of sandstones in cement concrete and some of the properties of such concrete in fresh and hardened states. Studies indicate that there is a promising future for the use of some selected sandstones in the production of cement concrete. The summary and information provided in this paper would provide new information and knowledge on the sustainable use of sandstone and its wastes for a greener concrete production.