Recycled-glass tiles tougher than concrete

Amresh Gunasingham, Straits Times 16 Dec 09;

Ngee Ann student Jocelyn Tay and Dr Sun with samples of tiles made from glass. The next goal is to develop materials with the quality of marble, but cheaper. -- PHOTO: NGEE ANN POLYTECHNIC

THOSE old glass dinner plates or wine bottles that normally end up in the dustbin could soon be remade into fancy floor and wall tiles in your home.

Researchers from Ngee Ann Polytechnic's Environmental and Water Technology Centre of Innovation have developed an eco-friendly way of converting discarded glass products into building materials with more than twice the strength of concrete.

With initial $70,000 seed funding sourced earlier this year, the researchers devised a method that involves mixing crushed glass with an inorganic binding agent that strengthens the bonding properties of glass particles, said lead researcher Sun Xiao Long.

The mixture is then poured into moulds to be shaped into floor tiles, insulation materials and concrete structures of various designs and colours - a pro-cess known as 'curing'. Placed in an oven at 100 deg C, the final product can be made in just six hours.

The research offers a more environmentally friendly way of using waste glass, which is currently either dumped as landfill waste or exported to countries such as Malaysia, where it is melted down at a scorching 1,600 deg C. This is not only energy-intensive, but also bad for the environment as it emits poisonous gases such as sulphur and nitrogen dioxide into the atmosphere.

Last year, more than 57,000 tonnes of glass waste were generated in Singapore, yet, due to poor sorting, the current recycling rate is less than 20 per cent.

Said Mrs Tam Li Phin, director of Ngee Ann's Centre of Innovation: 'This project demonstrates that waste is actually a misplaced resource if it is dumped.

'The challenge this research tries to address is how we can recycle, while also being environmentally sustainable.'

She said the centre was in discussions with a number of potential investors to raise up to $500,000 to take the research to the next level.

Dr Sun said the centre hopes to commercialise the technology over the next two years by building a pilot plant equipped to produce building materials on a larger scale. He added that more research was needed to make the binding agent stronger and cheaper.

Ngee Ann has approached the Housing Board to explore the use of the recycled products in its housing projects.

The next target is to develop materials with the quality of marble - highly valued for its toughness and aesthetically pleasing appearance - but cheaper.

Turning waste glass into wall tiles
Zul Othman, Today Online 16 Dec 09;

SINGAPORE - In the near future, building materials, such as floor and wall tiles, insulation materials and concrete, could be fashioned from bits of waste glass at only a fraction of its current recycling cost.

After a year of research, a team from the Centre of Innovation in Environmental and Water Technology at the Ngee Ann Polytechnic (NP), believes it has come up with a greener alternative by converting waste glass into building materials by crushing and blending the glass with an eco-friendly binding agent.

This is significant, said centre director Tam Li Phin.

"If we can harness technology to innovate and produce new materials from waste, this will not only create new business opportunities for local enterprises but also promote sustainable living," added Mrs Tam.

Last year, more than 57,000 tonnes of waste glass was generated in Singapore.

Currently, waste glass is either dumped at the Pulau Semakau landfill or sold to recycling companies overseas where the glass is re-melted at temperatures of 1,600°C.

Not only is this method expensive, it also consumes a lot of energy and generates massive amounts of carbon dioxide and other toxic gases.

The NP team said they are able to produce the building materials from glass that has been re-melted at only 100°C.

The Centre of Innovation's Dr Sun Xiaolong said the method is not only cheaper, but waste glass can also be used to create "money-spinning products" for use by the construction industry, thus reducing the "over-reliance on the supply of sand and cement from other countries".

The centre is in discussions with "several key industry" players to form a consortium to develop and market the green building product - as well as explore its potential for public housing