粉煤灰和石灰岩石粉对泡沫混凝土抗压强度的影响研究

Effect of Fly Ash and Limestone Powder on Compressive Strength of Foam Concrete

以昆明市巫家坝城市新中心某市政工程为依托,测试不同水胶比及干密度下泡沫混凝土的无侧限抗压强度(UCS),旨在探究掺合料类型、干密度以及水胶比对其无侧限抗压强度的影响。寻求出各因素对无侧限抗压强度的影响机制,并构建了无侧限抗压强度预测模型,以满足工程实践要求。结果表明:在高水胶比时,粉煤灰对泡沫混凝土UCS有积极作用,但提升程度小,而石灰岩石粉对其则具有显著的衰减作用;泡沫混凝土的UCS随干密度的增加而增长,且粉煤灰对UCS的提高幅度大于石灰岩石粉;当掺合料采用粉煤灰时,水胶比为0.40时的UCS更大;当掺合料是石灰岩石粉时,0.35的水胶比更能提升泡沫混凝土的UCS;灰色关联分析表明干密度与UCS间的关联程度大于水胶比,且构建的预测模型具有较高精度。

Relying on the municipal engineering of the first-level Land Development Project(Phase I)of Kunming Wujiaba Urban New Center,the unconfined compressive strength(UCS)of foamed concrete under different water-cement ratios and dry densities were tested to explore the influence of admixturetype,dry density and water-cement ratio on its ubconfined compressive strength.The results show that fly ash has a positive effect on the UCS of foam concrete at high water-cement ratio,but the degree of enhancement is small,while limestone powder has a significant attenuation effect on the UCS of foam concrete;the UCS of foam concrete increases with the increase in dry density,and the increase in UCS by fly ash on the UCS is greater than that by limestone powder;when fly ash is used as admixture,the UCS of foam concrete is greater when the water-cement ratio is 0.4,and when the admixture is limestone powder,the water-cement ratio is more favorable to improve the UCS of foam concrete when it is 0.35;gray correlation analysis indicates that the correlation between dry density and UCS is greater than water-cement ratio,and the constructed prediction model has a high accuracy.