New life of the building materials-recycle, reuse and recovery

摘要

Bulk of construction wastes generated through the dismantling process in a building redevelopment project creates many environment problems. Greater efforts are needed to put on the End-Of-Life (EOL) of building materials. Recycling, reusing and recovering of demolished wastes can either help relieve the landfill capacity or 'regain' some energy from existing building materials in order to reduce the embodied energy use for in the next new built building. This paper proposes to use 'energy saving potential' to quantify the amount of energy at the EOL phase that can be made usable in the building new life. Life cycle energy assessment was performed for the end-of-life phase of a high rise concrete commercial building. The energy associated with different waste management strategies was calculated to identify the options that can produce the highest energy saving in embodied energy. Recycling was found to have the highest energy saving potential of 53% while the energy saving potential of reusing was 6.2% and that of incineration was only 0.4%. Recycling strategy should be implemented for the building elements containing large amount of concrete (e.g. upper floor construction). Reusing instead of recycling should be adopted for the building parts with high aluminium content (e.g. windows).