贝灰-粉煤灰免烧砖的配合比及力学性能研究

A study on the mixing ratio and mechanical properties of shell ash-fly ash unfired brick

采用可再生资源贝灰、粉煤灰、水泥、石灰为主要原料,配以化学激发剂,研制一种绿色墙体材料——免烧砖。以力学性能和耐久性能为指标设计基本配合比。采用常温常压下水养护,分别研究了该免烧砖的抗压、抗折强度和抗冻性。试验结果表明,免烧砖最佳配合比为:粉煤灰40%、水泥25%、石灰15%、贝灰16%、石膏4%、SBR 3%、纤维0.10%、减水剂0.5%,砂灰比0.5,水灰比0.3。采用最佳配合比,振动成型免烧砖,单块砖的最小抗压强度大于30 MPa,15次冻融循环质量损失仅1%,冻后抗压强度达25 MPa,总体性能达到JC 239—2001《粉煤灰砖》标准要求。

A new green wall material- the unfired brick is produced by using shell ash,the recyclable resources, and fly ash, cement and lime as the main raw materials,and certain amount of chemical exeitator. The primary mixing ratio is designed on the basis of its mechanical properties and durability. When adopting water curing under normal temperature and normal pressure,the compressive strength,tensile strength and frost resistance of the unfired brick are measured. The results reveal that the optimum mixing ratio for unfired brick is：fly ash 40%,cement 25%,lime 15%,shell ash 16%,gypsum 4%,SBR 3%,fiber 0.10%,superplasticizer 0.5%,sand cement ratio 0.5 and water cement ratio 0.3. For the unfired brick formed by vibration with the optimum mixing ratio,the min. compressive strength of each brick is more than 30 MPa, the 15 times frost cycle mass loss is only l%,and the compressive strength alter frost reaches 25 MPa, the overall properties can meet the requirement as specified in standard JC 239-2001 ＂Fly Ash Brick＂.