RECYCLED AGGREGATE PRODUCTION IN HONG KONG: FROM CENTRALIZED PLANT TO MOBILE SETTING

To address the overwhelming demand for sustainable development, the government of the Hong Kong Special Administrative Region has organized numerous campaigns on waste reduction in recent years. Owing to the massive building redevelopment programme in Hong Kong, there is a huge volume of construction waste generated, among which more than 60% are of concrete waste. These solid wastes will soon exhaust all the available landfill areas in the territory. Hence, Recycled Aggregate (RA) is advocated. However, the current applications of recycled aggregate have confined to lower-grade concrete, such as pavements, roadwork, sub-base and fill. The major reason is its high variability in quality resulted partly from different concrete waste sources collected for centralized crushing in a centralized recycling plant. This paper proposes a mobile crusher for RA production which can: 1. reclaim RA from known sources; 2. maintain consistency of RA properties; 3. alleviate the traffic congestion in delivering concrete waste to a central crushing plant in the territory; 4. save in traveling time of discharging trucks; and 5. remove the requirement on the minimum boulder size to be handled by a centralized plant. The proposed mobile setting in reclaiming recycled aggregate can widen the applications of recycled aggregate and thus enlarge its consumption and demand, paving the way for reducing demand for raw materials, increasing demand for recycled materials and ultimately leading to sustainable construction.