纤维增强海砂再生混凝土基本力学性能研究

Mechanical properties of glass fiber reinforced sea sand recycled aggregate concrete

为研究纤维增强海砂再生混凝土的基本力学性能,以纤维掺量和再生粗骨料取代率为变量,对海砂混凝土进行了立方体抗压、劈裂抗拉和轴心抗压试验,并获得了应力-应变曲线.试验研究表明,纤维增强海砂再生混凝土的受压破坏形态和劈拉破坏形态与普通混凝土略有不同,纤维的掺入有效阻止了裂缝的迅速发展.棱柱体抗压强度和立方体抗压强度随取代率的增加和纤维掺量的增加而降低,通过拟合得到两者之间的换算系数为0.84.最后,基于过镇海模型提出了适用于不同纤维掺量和不同取代率的纤维增强海砂再生混凝土的本构关系,吻合结果较好.并采用应力截断法对抗压韧性进行了分析,抗压韧性随纤维掺量的增加而增加,说明纤维的掺入有效的提高了试件的耗能能力。

In order to study the basic mechanical properties of fiber-reinforced sea sand recycled aggregates concrete,cubic compressive strength,axial compressive strength and split tensile strength tests were performed on sea sand concrete taking fiber contents and replacement ratio as variables,and full stress-strain curve was obtained.Experimental research shows that the compressive failure mode and split tensile failure mode of fiber-reinforced sea sand recycled concrete are slightly different from ordinary concrete,and the incorporation of fiber effectively prevents the rapid development of cracks.The prismatic compressive strength and cubic compressive strength decrease with the increase of the replacement ratio and the increase of the fiber content.The conversion coefficient between the two is 0.84.Finally,the stress-strain model suitable for fiber-reinforced sea-sand recycled concrete of different fiber contents and different replacement ratio is proposed based on the Guo Zhenhai model,and the results agree well.The compressive toughness is analyzed by using the stress cut-off method.The compressive toughness increases with the increase of the fiber content,indicating that the incorporation of fibers effectively improves the energy consumption of specimens.