Modeling of the Breakage of Waste Concrete under Free Fall Conditions
In this study, free fall tests are conducted with the objective of understanding the breakage properties of waste concrete for the guide of the direction of the better comminution process. Waste concrete of 75mm×53mm is tested at various drop heights with or without heat pretreatment.Test results indicate that a block of waste concrete does not break by free fall, but eventually breaks by repeated free falls. The number of free falls required for complete separation of large aggregates from the cement mortar considerably reduced when the samples were heated at 400℃.Therefore, a great energy saving can be obtained when heating the waste concrete prior to crushing.The energy saving was found to be dependent on the height of free fall but in all cases, was still large enough to offset the additional energy required for heating. Also, it was found that the heat pre-treatment gives an additional advantage in that it produced cleaner recycled aggregates. This may result from easier detachment of cement mortar from the aggregates due to weakening of bonding forces by heating.By analyzing the size distribution of the crushed product, a free-fall breakage model is developed using the particle breakage ratio and the breakage pattern. The developed model can be used to predict and to analyze waste concrete processing circuit.
Waste concrete Breakage Liberation Drop test Heat treatment
Kwan Ho Kim Hee Chan Cho Ji Hoe Kwon Ji Whan Ahn
Energy System Engineering, Seoul National University, Korea
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
399-406
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）