‘Manufactured’ sand is solution to mining woes

Vijay Mohan

Tribune News Service

Chandigarh, June 24

As large-scale and, at times, illegal mining of riverbed sand and its adverse environmental impact remains a cause for concern, the Council for Scientific and Industrial Research (CSIR) has come up with an eco-friendly and cost-effective alternative in the form of “manufactured sand” that is produced from recycled aggregates and industrial byproducts.

Manufactured sand is manufactured from materials other than natural resources using various physical and chemical processes and can be used either as full or partial replacement of natural sand in construction.

The increasing demand due to infrastructure development has led to extensive extraction of natural river sand that physically impacts the ecosystems in the vicinity of rivers and coasts and also makes the area susceptible to disaster. Further, directives from the courts and the National Green Tribunal have made the construction industry explore alternatives to natural sand without compromising on quality.

With this background, CSIR’s Central Building Research Institute at Roorkee has initiated a project, “Studies on manufactured fine aggregate as alternative to natural sand for production of sustainable mortar and concrete,” and is collaborating with industrial partners to assess its suitability and efficacy in construction.

According to CSIR scientists, manufactured sand can be classified as natural crushed rock sand (CRS), recycled fine aggregates (RFA) and industrial byproducts. CRS is produced by crushing rock deposits to obtain well-graded sand, which is generally more angular and has a rougher surface texture than naturally weathered sand particles.

RFA is produced from reprocessing of construction or demolition waste like concrete, bricks, glass and bitumen and also contributes in tackling the growing waste disposal problem. Industrial byproducts include blast furnace slag, waste foundry sand, coal bottom ash, cement kiln dust and wood ash, which have an advantage as no further process is needed, thereby saving energy.

Scientists said since the increasing dependence on natural sand has led to river ecosystem disruption and environmental imbalance, finding an alternative to natural sand has become a mandate not only for the construction industry but also for environmental protectors.

Over the last few years, developed countries have made major inroads into the production of alternative sand and its adaptations.