粉煤灰和矿渣粉对混凝土性能的影响研究  

The Influence of Fly Ash and Slag Powder on the Performance of Concrete

作　　者：孙宏图 张强 蔡志远 刘帅 姜瑞双 黄智德 

机构地区：[1]济南金曰公路工程有限公司,山东济南250014 [2]山东省交通科学研究院,山东济南250031 [3]山东交通学院交通土建工程学院,山东济南250357

出　　处：《混凝土世界》2023年第7期53-56,共4页China Concrete

摘　　要：采用矿物掺合料替代水泥是降低混凝土成本和提升混凝土性能的有效途径,原材料特性和混凝土配合比对矿物掺合料使用效果的影响值得关注。研究了粉煤灰和矿渣粉替代水泥对C40、C50混凝土的工作性和抗压强度的影响,结果表明:适量地掺入粉煤灰和矿渣粉有助于改善混凝土的工作性,掺入20%的粉煤灰可使C40混凝土的坍落度由175mm提高至200mm,掺入25%的矿渣粉可使C50混凝土的扩展度由450mm提高至500mm;粉煤灰和矿渣粉的作用效果受其掺量和混凝土配合比的影响,当掺合料掺量较高且水胶比较低时,混凝土的黏度大,过于干硬不易施工;相比矿渣粉,粉煤灰对混凝土强度的影响更为显著,粉煤灰的掺入使混凝土的早期强度降低但后期强度上升明显;建议掺入20%的粉煤灰和20%的矿渣粉等量替代水泥配制C40混凝土,建议掺入25%的矿渣粉等量替代水泥配制C50混凝土。Replacing cement with mineral admixtures is an effective way to reduce concrete costs and improve concrete performance.The impact of raw material properties and concrete mix proportion on the effectiveness of mineral admixtures is worth paying attention to.Study the effect of replacing cement with fly ash and slag powder on the workability and compressive strength of C40 and C50 concrete.The results show that adding an appropriate amount of fly ash and slag powder can improve the workability of concrete.Adding 20%fly ash can increase the slump of C40 concrete from 175mm to 200mm,and adding 25%slag powder can increase the expansion of C50 concrete from 450mm to 500mm.The effect of fly ash and slag powder is influenced by their dosage and concrete mix proportion.When the dosage of admixtures is high and the water cement ratio is low,the viscosity of concrete is high,making it difficult to construct if it is too dry and hard.Compared to slag powder,fly ash has a more significant impact on the strength of concrete.The addition of fly ash reduces the early strength of concrete but significantly increases its later strength.Recommend to mix 20%fly ash and 20%slag powder to replace cement in the preparation of C40 concrete,and recommend 25%slag powder to replace cement in the preparation of C50 concrete.

关 键 词：矿物掺合料 坍落度 扩展度 抗压强度 混凝土配合比 

分 类 号：TU528[建筑科学—建筑技术科学]