粉煤灰掺量对高性能自密实混凝土抗压强度发展影响分析

Influence of Fly Ash Content on Compressive Strength Development of High Performance Self-Compacting Concrete

粉煤灰对自密实混凝土的工作性能、抗压强度和耐久性能等有着显著的影响。为了探究粉煤灰掺量对自密实混凝土抗压强度发展规律的影响,配制了粉煤灰掺量为30%、45%、60%(体积分数),水灰比为1.05、1.15、1.25(体积比)的自密实混凝土并进行立方体抗压强度试验,对其3 d、7 d、28 d、90 d抗压强度的变化规律进行了分析。结果表明,随着粉煤灰掺量的增加,混凝土抗压强度逐渐减小。然后对3 d/28 d、7 d/28 d、90 d/28 d的强度比值进行分析,结果表明,粉煤灰对混凝土早期强度影响较小,对后期影响较大。最后借鉴欧洲规范CEB-FIP探究了粉煤灰与水泥混合下的复合粉体对自密实混凝土抗压强度影响系数,为相关工程应用提供理论依据。

Fly ash has a significant impact on the workability,strength,and durability of self-compacting concrete.In order to explore the influence of fly ash content on the compressive strength of self-compacting concrete,self-compacting concrete with 30%,45%,and 60%(volume fraction)fly ash content and water-cement ratio of 1.05,1.15,and 1.25(volume ratio)was prepared,and the cube compressive strength tests of 3 d,7 d,28 d,and 90 d were carried out.The results show that with the increase of fly ash content,the compressive strength of concrete gradually decreases.And then the strength ratio of 3 d/28 d,7 d/28 d,and 90 d/28 d were analyzed.The results show that fly ash has little influence on the early strength of concrete,but has a greater influence on the later strength.Finally,referring to the European standard CEB-FIP,the influence coefficient of the composite powder mixed with fly ash and cement on compressive strength of self-compacting concrete is explored,which provides a theoretical basis for related engineering applications.