**5. Characteristics of cold-bonding recycling coarse aggregates**

The promotion of up-to-date green building materials was often impeded by the lack of relevant standards or specifications cited to verify their characteristics (Chang et al., 2009). To avoid such obstruction affecting the application of cold-bonding recycling coarse aggregates in the future, the characteristics of cold-bonding recycling coarse aggregates were certified in accordance with ASTM C33. The aggregate gradation significantly affects on workability, strength, durability, and economy of concrete (Mehta, 1986; Mindess & Young, 1981; Tsai et al., 2006). Therefore the gradation of cold-bonding recycling coarse aggregate was established by the above-mentioned five various diameter particles according to the mean of upper and lower limit from size number 56 and 6 recommended by ASTM C33.
