Waste from demolished buildings may be reused

Materials from demolished buildings and incinerators may well find new use in the construction industry, which is seeking to wean itself from costly raw materials.

The Building and Construction Authority (BCA) yesterday unveiled a broad-based plan to beef up the building industry’s resilience against external pressures, such as the export ban on land sand by Indonesia, which has raised the cost of producing concrete.

Under the BCA’s Sustainable Construction Masterplan, research will be done into how building waste can be ploughed back into construction.

However, because waste materials need a lot of processing to remove impurities such as paint, more studies will be done into how such waste materials can be recycled, ‘especially if we want to use it for structural purposes’, the BCA said.

According to industry estimates, construction and demolition waste comes to about 1.2 million tonnes per year, of which about one million tonnes is concrete waste.

The BCA is also looking into ways to use copper slag - waste obtained from ship-blasting works - in place of sand.

Meanwhile, recycled concrete is being used for building road kerbs and drains in projects such as The Sail@Marina Bay and St Regis Hotel and Residences.

The Land Transport Authority is also running a trial on using recycled materials for road-base construction.

Dry walls - built with board mounted on metal frames with insulating material inside - are also being advocated as substitutes for conventional brick walls, which require sand to build.

The dry wall in City Developments’ residential project, City Square Residences, costs 24 per cent less - and is being built four times faster - than conventional brick walls built with sand at current prices.

The BCA, which has for some time now been trying to get the industry to switch to steel construction, had estimated before the sand- and granite-supply disruptions that a steel-based building would cost about 8 per cent to 10 per cent more than a concrete-based one to build.

This price gap has narrowed in recent weeks, however, following the hikes in sand and granite prices, which the BCA estimates will push construction costs up by about 7 per cent on average.

The president of the Singapore Contractors’ Association, Mr Desmond Hill, welcomed the BCA’s call to use recycled materials, but said more needed to be done to make such recycled materials more readily available.

He said: ‘I think we need more waste material recycling plants. The Government also needs to look at how to make it easier for contractors to get hold of recycled materials.’