Pull-Out Strength and Bond Behavior of Prestressing Strands in Prestressed Self-Consolidating Concrete.
Pull-Out Strength and Bond Behavior of Prestressing Strands in Prestressed Self-Consolidating Concrete.
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预应力自密实混凝土中预应力钢丝的拉拔强度和粘结性能
DOI：
10.3390/ma7106930
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发表时间：
2014-10-10
期刊：
影响因子：
--
通讯作者：
Xing F
中科院分区：
文献类型：
--
作者：
Long WJ;Khayat KH;Lemieux G;Hwang SD;Xing F
随着自密实混凝土（SCC）在世界范围内的广泛应用，确保自密实混凝土具有与常规流动性的适当固结混凝土相似的均匀的现场力学性能是非常重要的。确保SCC的适当稳定性对于提高现场力学性能的均匀性至关重要，包括与嵌入钢筋的粘结，这对于考虑预应力应用SCC规范的结构工程师至关重要。在这项调查中，六个墙元件测量1540 mm × 2150 mm × 200 mm使用五个SCC混合物和一个标准稠度的参考高性能混凝土（HPC），以评估预应力钢绞线和混凝土之间的粘结强度的均匀性，以及从芯沿着墙元件获得的抗压强度的分布。对用于浇注墙体构件的经评估的SCC混合物进行配比，以达到680 ± 15 mm的坍落度稠度和80%的最小沉箱填充能力，以及0.5至1的视觉稳定性指数。鉴于SCC混合物的粘度和静态稳定性的差异，五个壁元件在原位抗压强度和拔出粘结强度方面表现出不同程度的均匀性。试验结果还表明，尽管SCC的高流动性，稳定的混凝土可以导致更均匀的原位性能比正常稠度的高性能混凝土受到机械振动。
With the extensive use of self-consolidating concrete (SCC) worldwide, it is important to ensure that such concrete can secure uniform in-situ mechanical properties that are similar to those obtained with properly consolidated concrete of conventional fluidity. Ensuring proper stability of SCC is essential to enhance the uniformity of in-situ mechanical properties, including bond to embedded reinforcement, which is critical for structural engineers considering the specification of SCC for prestressed applications. In this investigation, Six wall elements measuring 1540 mm × 2150 mm × 200 mm were cast using five SCC mixtures and one reference high-performance concrete (HPC) of normal consistency to evaluate the uniformity of bond strength between prestressing strands and concrete as well as the distribution of compressive strength obtained from cores along wall elements. The evaluated SCC mixtures used for casting wall elements were proportioned to achieve a slump flow consistency of 680 ± 15 mm and minimum caisson filling capacity of 80%, and visual stability index of 0.5 to 1. Given the spreads in viscosity and static stability of the SCC mixtures, the five wall elements exhibited different levels of homogeneity in in-situ compressive strength and pull-out bond strength. Test results also indicate that despite the high fluidity of SCC, stable concrete can lead to more homogenous in-situ properties than HPC of normal consistency subjected to mechanical vibration.