Mechanical properties of synthetic aggregate pelletized by waste concrete fines in Vietnam

Due to rapid industrialization and economic growth, the generation of construction demolition waste (CDW) from activities demolishing buildings is increasing in Vietnam. The Vietnamese Government has regulations on recycling collecting CDW for reuse, environmental protection through Circular No. 08/2017/TT-BXD 2017, Directive 41/CT-TTg 2020. Waste concrete fines (WCF) are generated during process or crushing materials. To save natural resources increase rate, a disc pelleting technology been used recycle WCF. pellet machine disk with 1.5m diameter 0.3m depth; tilted at an angle 55 degrees rotation speed 15 22 rpm; capacity 0.5 0.8 tons per hour. This paper presents results pelletizing WCF research produce synthetic aggregate (SA). SA pelletized by cement had apparent specific gravity 2.45 – 2.55 g/cm3, dry bulk 1.85 1.95 value 19.2 29.9%, LA (Los Angeles) 23 33% water absorption around 13.2%. mechanical properties meet requirement TCVN 11969:2018, recycled type II concrete.