Think about how many multi story buildings there are in cities, and that at some stage they are going to be demolished and re-built. Most of them are made of concrete and reinforcing steel, not easy to move once you have bashed it down to ground level. A tangled mess of steel and concrete.

A New Zealand Company, Award Attachments Ltd, which has its roots in the demolition business, has developed a range of tools to make this work so much easier and effective. Concrete cutting and crushing jaws, steel cutting jaws, all fit quickly onto conventional hydraulic digger arms.

Pulveriser

These break up the concrete into 100mm to 150mm pieces. Steel cutting jaws then lets you cut and extract the steel beams and bar, and this is recovered and sold as scrap. The crushed concrete can be easily loaded onto trucks and removed. Sometimes processed more as building site fill, drainage material and the like.

Concrete Shear 

Sold in a growing number of countries, with all manufacturing done right here in NZ. Another example of great Kiwi ingenuity at work. But this time actually also helping save the planet by the recycling made possible. Ward Attachments Ltd named as one of the Deliottes Fastest 50 growing Companies in NZ, 2008, won Exporter of the Year title in 2007. 

For more details, see http://www.a-ward.co.nz/index.php

Another Green idea

The Laputa Eco Construction Material Co Ltd in Hong Kong takes waste glass bottles, construction and demolition wastes and fly ash from power plants, to produce paving blocks for pathways and roads that help reduce air pollution.

Laputa was started in 2005 and holds the license for the technology developed at the Hong Kong Polytechnic University, according to company consultant Henry Chiu.

The technology to make the eco-blocks could prove a boon to several industries, ranging from construction and waste disposal. Even the government, according to Mr Chiu, could save millions of dollars by eliminating the need to ship unwanted construction and demolition waste to the Chinese mainland.

"The technology actually replaces or uses three environmental ingredients," Mr Chiu said. "We replace the sand with crushed glass from waste bottles, we replace the aggregate in the paving blocks with recycled aggregate from construction waste, and we combine fly ash from the city's power plants. This is what we call the eco-glass block."

The company also produces so-called "air pollution removal pavers" - paving blocks that contain titanium dioxide, which converts or helps to convert the nitrogen oxides from vehicle exhaust, turning it into nitrate, which is basically a fertiliser.