ABSTRACT
Abstract This repor t concerns the technology of recycl ing the dust concrete generated from broken cement concrete lumps. Currently the broken concrete lumps r e s u l t i n g from the demolition of cement concrete s t ruc tu re s a re crushed for reuse as aggregate. In the process of crushing, an enormous amount of dust concrete i s generated, and there is no e f fec t ive method a v a i l a b l e for the treatment or disposal of i t . In order to u t i l i z e t h i s dust concrete , we t r i e d to add i t to waste pavement asphal t concrete a t the r a t e of approximately 20%. This r e su l t ed in the asphal t contained in the waste aspha l t mixture bonding to the dust concrete, and the aggregates were separated from the aspha l t as well . Next, indiv idual ly separated independent aggregates were divided from the dust asphal t , and were recovered one by one. After recovery, the aggregates can be reused as a component of such bui ld ing mater ia l as a concrete or asphal t mixture. The dust a spha l t can be reused as a pavement f i l l e r or a back f i l l i ng mater ia l for which waterproofness i s required. Keywords: Waste Concrete, Dust Concrete, Waste Asphalt Mixture, Aggregate Re-mater ia1i za t ion,
1 In t roduc t ion
The p rese rva t ion of the global environment and the e f fec t ive u t i l i z a t i o n of valuable resources are s i g n i f i c a n t i ssues . In Japan, a g rea t deal of waste has been generated from bui ld ing construct ion, therefore i t s recyc l ing i s p a r t i c u l a r l y important. Of t h i s waste, the broken cement concrete lumps generated in the course of bui lding demolition are recycled for reuse as aggregate . Waste aspha l t mixture generated from road cons t ruc t ion i s crushed for reuse as a road subbase mater ia l , by means of an e s t ab l i shed recycl ing technology n . But the treatment or disposal of large q u a n t i t i e s of dust concrete being generated in the crushing process has given r i s e to a new problem. Barely 50% of such waste i s recycled, thus i t is s t i l l i n su f f i c i en t . This paper proposes a method of recovering aggregates from waste aspha l t lumps by using dust concrete, for recycl ing.
Table 1 . Dus t ma te r i a l s used .
