钢纤维及陶粒掺量对轻质混凝土基本力学性能的影响

制备了3种强度等级共13组配合比的钢纤维增强轻质混凝土（Steel Fibre Reinforced Lightweight Aggregate Concrete，SFRLAC），测量了立方体抗压强度、劈裂抗拉强度和轴心抗压强度，得到了SFRLAC轴心受压应力-应变曲线。试验结果表明，钢纤维能小幅度提高轻质混凝土（Lightweight Concrete，LC）的抗压强度，随陶粒比率（Haydite Ratio，V_h）的增大，抗压强度降低，且强度等级越低，降幅越大。钢纤维能显著提高LC的劈裂抗拉强度，钢纤维对低强度等级LC劈裂抗拉强度的贡献优于对高强度等级LC的贡献。低强度等级SFRLAC （LC30和LC40）的劈裂抗拉强度受V_h的影响较大，而高强度等级SFRLAC （LC50）与之相反。当V_h达到80%时，V_h不再是影响SFRLAC劈裂抗拉强度的主要因素，而钢纤维的增强效应显著。试块的破坏形态表明钢纤维能改善LC的塑性。V_h对抗拉强度的降低效应远大于对抗压强度的降低效应。建立了SFRLAC轴心抗压强度与立方体抗压强度的关系式。SFRLAC应力-应变曲线综合体现了钢纤维的增强效应和陶粒的削减作用，陶粒降低LC的峰值应力和韧性，钢纤维主要提高LC的韧性。

Influence of steel fibre and haydite adding content on the basic mechanical properties of lightweight concrete

13 groups of steel fibre reinforced lightweight aggregate concrete (SFRLAC) with three kinds of strength grades were prepared. The cube compressive strength, splitting tensile strength and axial compressive strength were measured, the stress-strain curves of SFRLSC axial compression were obtained. The results show that the steel fibre can improve the compressive strength of lightweight concrete (LC) slightly, the compressive strength decreases with the increase of the haydite ratio (V_h), and the lower the strength grade is, the greater the degree decreases. Steel fibre have a significant improvement on the splitting tensile strength of LC, steel fibre on the low strength grade LC splitting tensile strength contribution is better than that of high strength grade LC. The splitting tensile strength of the low strength grade SFRLAC (LC30 and LC40) is strongly influenced by V_h, while the high strength grade SFRLAC (LC50) is opposite. When V_h reaches 80%, the V_h is no longer the main factor influencing the splitting tensile strength of SFRLAC, but the enhancement of steel fibres is remarkable. The failure of the specimen shows that steel fibre can improve the plasticity of LC. The reduction effect of the V_h on tensile strength is much greater than that of compressive strength. The relationship between axial compressive strength and cube compressive strength of SFRLAC was established. The SFRLAC stress-strain curves reflect the reinforcing effect of steel fibre and the reduction effect of haycite. The haycite decreases the peak stress and toughness of LC, while the steel fibre mainly enhances the toughness of LC.