自燃煤矸石粗集料特性对混凝土拌合物工作性影响研究

The Effects on Workability of Concrete Mixture of Spontaneous Combustion Coal Gangue Coarse Aggregate Characteristics

利用自燃煤矸石取代天然石材作粗集料配制煤矸石砂轻混凝土，并实现预拌混凝土大流动性的目标。采用正交设计，选取代表粗集料特性的附加用水量、砂率及颗粒级配范围3个影响因素，研究三者对自燃煤矸石砂轻混凝土拌合物工作性的影响及变化规律。结果表明，附加用水量对自燃煤矸石砂轻混凝土拌合物工作性影响最大，其次是砂率及煤矸石级配。当粗集料附加用水量为吸水率的78％、砂率为44％及煤矸石颗粒级配范围为m（5-10mm）：m（10-15mm）：m（15-20mm）=7：47：46时，拌舍物在保持粘聚性和保水性能良好的前提下，流动性最大，且满足C20强度等级的设计要求。

Using spontaneous combustion coal gangue Instead of natural stone as coarse aggregate to prepare gangue sand lightweight concrete, and realizing the mobility target of ready-mixed concrete. The orthogonal design was used to select the additional water consumption of coarse aggregate, sand ratio and gradation of the coarse aggregate particles range as three influencing factors for the research of spontaneous combustion the gangue sand lightweight concrete mixture workability and variation. The results showed that： the additional amount of water impacted mostly on the spontaneous combustion coal gangue sand lightweight concrete mixture workability, followed by the grading of gangue and sand ratio. When the coarse aggregate additional amount of water is 78% of water absorption rate, sand ratio is 44% and gangne particle size distribution range is m（5-10 mm） ： m（10-15 mm） ： m（15-20 mm） being 7 ： 47 ： 46, the mixture under the premise of maintaining good cohesiveness and water retention properties, it has the most liquid, and meet the design requirement strength grade of C20.