集料增强粉煤灰泡沫混凝土性能试验研究与模型预测

Experimental study and model prediction on performance of aggregate-reinforced fly ash foamed concrete

研究了水胶比、砂胶比、粉煤灰掺量、石英砂和石英粉质量比例对集料增强粉煤灰泡沫混凝土立方体抗压强度和劈裂抗拉强度的影响,测试了不同砂胶比集料增强粉煤灰泡沫混凝土的孔结构和微观形貌;通过灰色理论分析了4种因素对集料增强粉煤灰泡沫混凝土强度的影响,对集料增强粉煤灰泡沫混凝土强度进行预测,并对预测的结果进行误差分析。结果表明:水胶比0.4、砂胶比0.8、粉煤灰掺量25%、石英粉与石英砂质量比例1∶1时试件立方体抗压强度与劈裂抗拉强度较好;不同砂胶比的集料增强粉煤灰泡沫混凝土孔径分布范围为0.1~10μm,砂胶比0.8的试件孔径分布范围较好,微观结构致密,微观形貌良好;4种因素对集料增强粉煤灰泡沫混凝土立方体抗压强度的影响程度由大到小依次为砂胶比、石英粉与石英砂比例、水胶比、粉煤灰掺量;传统灰色理论模型与MGM灰色理论模型对预测立方体抗压强度与劈裂抗拉强度效果较好,模型精度均达到二级,试验结果和预测模型可以为集料增强粉煤灰泡沫混凝土的研究和应用提供参考。

The effects of water binder ratio,sand binder ratio,fly ash content,quartz sand and quartz powder mass ratio on cubic compressive strength and splitting tensile strength of aggregate-reinforced fly ash foamed concrete were studied.The pore structure and micro morphology of aggregate-reinforced fly ash foamed concrete with different sand binder ratios were tested.The influences of four factors on the strength of aggregate-reinforced fly ash foamed concrete were analyzed through gray theory,the strength of aggregate-reinforced fly ash foamed concrete was predicted,and the error of the prediction results was analyzed.The results show that when the water binder ratio is 0.4,sand binder ratio is 0.8,the content of fly ash is 25%,and the mass ratio of quartz powder to quartz sand is 1∶1,the cubic compressive strength and splitting tensile strength of the test piece are better.The pore size distribution of aggregate-reinforced fly ash foamed concrete with different sand binder ratios ranges from 0.1 to 10μm.The pore size distribution range of the specimen with a sand cement ratio of 0.8 is good,with a dense microstructure and good microstructure.The influence degree of four factors on cube compressive strength of aggregate-reinforced fly ash foamed concrete from large to small is sand binder ratio,quartz powder and quartz sand ratio,water binder ratio and fly ash content.The traditional grey theory model and MGM grey theory model have good effects on predicting the cubic compressive strength and splitting tensile strength,and the model accuracy reaches the second level.The test results and prediction model can provide reference for the research and application of aggregate-reinforced fly ash foamed concrete.