风积沙的掺入对浮石轻骨料混凝土性能的影响

Impact of Mixed Aeolian Sand on the Properties of Pumice Lightweight Aggregate Concrete

本文通过风积沙内掺替代部分河砂,分别掺入0%、10%、20%和30%质量的风积沙代替相同质量的河砂,配制风积沙浮石轻骨料混凝土。研究风积沙的掺入对混凝土立方体抗压强度与轴心抗压强度的影响,应用SEM从微观上观察内部的形貌变化特征,并通过轴心抗压应力-应变曲线与《轻骨料混凝土结构技术规程》的应力-应变关系曲线进行了对比,建立了风积沙浮石轻骨料混凝土的本构模型。结果表明：风积沙可以替代部分河砂作为混凝土的细骨料,且对抗压强度值的提升贡献较大,其替代率为20%~30%为宜;采用《轻骨料混凝土结构技术规程》中的应力-应变关系曲线的上升段与有理分式的下降段更能真实的反应浮石轻骨料混凝土的本构关系。

Replacing part of river sand with aeolian sand, by mixing 0% , 10% , 20% and 30% mass fraction of aeolian sand instead of the same quality of river sand to configure aeolian sand pumice lightweight aggregate concrete. Experimental study on the influence of incorporation the different dosage of aeolian sand on cube and axial compressive strength of concrete, with adoption of SEM to observe the inner morphology characteristics on the micro level, along with the comparison been applied between the axial compressive stress-strain curve and the ＂ Technical specification for lightweight aggregate concrete structures＂ derived stress-strain curve, the constitutive model of aeolian sand pumice lightweight aggregate concrete was established. Results indicated that aeolian sand can replace part of the river sand as fine aggregate concrete and enhance the compressive strength of concrete, its replacement rate of 20% to 30% is appropriate. The ascending branch of the ＂ Technical specification for lightweight aggregate concrete structures＂ derived stress-strain curve and the descending branch of rational fraction can reflect the constitutive relation of aeolian sand pumice lightweight aggregate concrete more actually.