钢管RPC界面作用试验研究
发布时间：2019-06-04 02:47
【摘要】：钢管活性粉末混凝土(简称钢管RPC)是在钢管中填充高性能水泥基复合材料活性粉末混凝土(RPC)而形成的,具有比普通钢管混凝土更高的强度、延性、韧性等优点。钢管RPC界面作用是钢管RPC这一组合结构发挥组合效应的重要因素。近年来钢管RPC工程应用越来越多,而除了受压性能外,钢管RPC静力性能研究尚不够深入。为了完善钢管RPC受力性能理论,促进工程应用,本文进行了钢管与RPC界面之间的粘结-滑移性能研究。本文制作了共27根钢管RPC直接推出试验试件,试验参数包括截面含钢率(4.73%、6.89%、8.65%、10.43%、12.22%,通过变化钢管壁厚)、钢纤维体积掺量(0%、1%、2%、3%)和养护温度(20℃、90℃),取得了如下结果和结论:1.获得了钢管RPC荷载-滑移全过程试验曲线。试验结果分析表明,钢管RPC的荷载-滑移全过程曲线与普通钢管混凝土的类似,也可分为三个阶段:初始滑移段、摩阻滑移段、后滑移段。初始滑移段的界面作用主要由化学胶结力与机械咬合力和摩擦力组成.,摩阻滑移段主要由摩擦力与机械咬合力组成,此阶段荷载-滑移曲线会产生上下波动;后滑移段主要由摩擦力与新界面的机械咬合力组成。2.获得了钢管纵、横向应变沿荷载方向的分布曲线。钢管纵向应变沿试件轴线方向呈三角形分布模式;横向应变沿试件轴线方向呈凸型曲线分布模式,钢管中部的横向应变大于试件两端的横向应变,钢管对RPC产生被动约束。3.养护温度、截面含钢率和钢纤维体积掺量对钢管-RPC界面初始粘结强度和极限粘结强度的影响规律不同。对于初始粘结强度,养护温度影响最大,钢纤维体积掺量次之,而截面含钢率最小;对于极限粘结强度,截面含钢率影响最大,养护温度次之,而钢纤维体积掺量最小。具体而言,三个参数的影响规律如下:(1)养护温度有助于促进RPC中化学成分的充分反映,产生的水化硅酸钙更容易与钢管表面紧密黏结,能有效提高钢管-RPC界面的化学胶结力,是粘结强度的最主要影响参数之一。当温度从20℃升高到90℃时,钢管-RPC界面初始粘结强度和极限粘结强度分别提高了 36%和 11%。(2)钢管约束轴力作用下RPC的径向变形,截面含钢率越大,约束效应越大,钢管-RPC界面的摩擦力越大。截面含钢率的影响随荷载的增大而增大;当荷载较小时,RPC径向变形不大,截面含钢率的影响小,即对初始粘结强度的影响不明显;当荷载增大到极限荷载时,RPC径向变形大,截面含钢率的影响大,钢管-RPC界面摩擦力显著增大,极限粘结强度随截面含钢率线性增加。(3)钢纤维掺量对极限粘结强度的影响不明显,对初始粘结强度的影响较大,影响程度与钢纤维掺量的关系较为复杂。钢纤维掺量从0%到1%,初始粘结强度降低了 3%,但钢纤维掺量从1%到3%,初始粘结强度提高了 92%。
[Abstract]:Steel tube reactive powder concrete (RPC) is formed by filling high performance cement-based composite reactive powder concrete (RPC) in steel tube, which has the advantages of higher strength, toughness and toughness than ordinary concrete-filled steel tube (CFST). The interface function of steel pipe RPC is an important factor for the composite structure of steel pipe RPC to exert the combination effect. In recent years, there are more and more applications in steel pipe RPC engineering, but in addition to compression performance, the research on static performance of steel pipe RPC is not deep enough. In order to perfect the theory of mechanical properties of steel pipe RPC and promote the engineering application, the bond-slip behavior between steel pipe and RPC interface is studied in this paper. In this paper, a total of 27 steel pipe RPC test pieces have been made. The test parameters include section steel content (4.73%, 6.89%, 8.65%, 10.43%, 12.22%, by changing the wall thickness of the steel pipe), and the test parameters include the steel content of the section (4.73%, 6.89%, 8.65%, 10.43%, 12.22%). The volume content of steel fiber (0%, 1%, 2%, 3%) and curing temperature (20 鈩，
本文编号：2492415
[Abstract]:Steel tube reactive powder concrete (RPC) is formed by filling high performance cement-based composite reactive powder concrete (RPC) in steel tube, which has the advantages of higher strength, toughness and toughness than ordinary concrete-filled steel tube (CFST). The interface function of steel pipe RPC is an important factor for the composite structure of steel pipe RPC to exert the combination effect. In recent years, there are more and more applications in steel pipe RPC engineering, but in addition to compression performance, the research on static performance of steel pipe RPC is not deep enough. In order to perfect the theory of mechanical properties of steel pipe RPC and promote the engineering application, the bond-slip behavior between steel pipe and RPC interface is studied in this paper. In this paper, a total of 27 steel pipe RPC test pieces have been made. The test parameters include section steel content (4.73%, 6.89%, 8.65%, 10.43%, 12.22%, by changing the wall thickness of the steel pipe), and the test parameters include the steel content of the section (4.73%, 6.89%, 8.65%, 10.43%, 12.22%). The volume content of steel fiber (0%, 1%, 2%, 3%) and curing temperature (20 鈩，
本文编号：2492415
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