POTENTIAL FOR RECYCLING DEMOLISHED CONCRETE AND BUILDING RUBBLE IN KUWAIT

Demolished concrete and building rubble waste presents an environmental problem in terms of ways of disposal and use. The amount of structural waste in Kuwait for 1996 was around 2 million tons, out of which 30% is concrete. The recyclable concrete reached 764 thousand tons in 2002 and is expected to exceed 1210 thousand tons in 2020 as many old buildings will be demolished. Dumping was the only measure taken previously, but it is no longer a valid option as it occupies land which is in great demand for urban development. Recycling that form of solid waste into construction is a better solution. In Kuwait attempts are being made in adopting the recycling approach in the last few years. This paper states out the problem and presents a review of these attempts and research carried out to asses the suitability of crushed concrete and masonry for use in concrete and in sand lime brick manufacture. Recycled concrete can be crushed and utilized as aggregates in the production of new concrete. The results also show that fine powder, obtained from crushed concrete and masonry blocks contains adequate amounts of lime (Ca(OH)₂) resulting from the hydration process which may react with silica under high temperature and pressure to produce lime-silca bricks. The production process including autoclaving time and temperature is included along with the properties of the resulting bricks. The reported properties include specific gravity, compressive strength, and absorption. The properties of the resulting bricks are compared with the specifications requirements.

• INTRODUCTION

• TEST METHODOLOGY

• RESULTS AND DISCUSSION

• CONCLUSIONS

• REFERENCES