Structural Engineering Studies on Reinforced Concrete Structure using Neutron Diffraction
Structural Engineering Studies on Reinforced Concrete Structure using Neutron Diffraction
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利用中子衍射对钢筋混凝土结构进行结构工程研究
DOI：
10.21741/9781945291173-5
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
S. Harjo
中科院分区：
文献类型：
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作者：
T. Mukai;M. Kanematsu;H. Suzuki;K. Kusunoki;S. Harjo
过去的研究已经证明，中子衍射法可以替代传统的应变计来测量埋入混凝土中的钢筋的应力分布。本研究探讨了用中子衍射法评估粘结应力的可能性，以期为钢筋混凝土结构的结构工程研究寻找更多的中子衍射法。用中子衍射法测得的粘结应力分布出现多个峰，表明粘结应力沿埋入钢筋方向的变化不均匀。这一结果表明，高空间分辨率的中子衍射技术使研究由横肋引起的局域键阻成为可能。用中子衍射法测得的粘结应力分布有望对钢筋混凝土结构中钢筋与混凝土之间的粘结机理有更详细的了解。钢筋混凝土(RC)被广泛地应用于各种建筑和土木工程结构中，是一种众所周知的组合结构，其中抗拉强度和延性相对较低的混凝土由具有高抗拉强度和/或延性的钢筋等钢筋加固。通常，定量评估钢筋与周围混凝土之间的粘结抗力对于讨论钢筋混凝土结构的性能是很重要的[1-4]。在我们以前的研究中，我们已经研究了中子衍射技术作为传统应变计的替代方法来测量埋入混凝土中的钢筋的应力的潜力。我们的第一个相关工作是在JRR3(日本研究堆3号)使用工程衍射仪RESA-1进行的，我们证明了中子衍射技术可以成为一种新的埋入混凝土中的钢筋的应变测量方法[5，6]。最近，在日本质子加速器研究综合体(J-PARC)的材料和生命科学实验设施(MLF)上，利用飞行时间(TOF)中子衍射仪TAKUMI成功地测量了埋入钢筋的三维变形行为，包括轴向和横向应变。此外，TAKUMI的一些应用研究表明，中子衍射技术可用于评估混凝土中钢筋锈蚀和裂缝产生的粘结劣化[8]。如上所述，我们之前的研究通常讨论钢筋残余应力之间的粘结条件2016：ICRS-10材料研究论坛有限责任公司材料研究论文集2(2016)25-30 DOI：http://dx.doi.org/10.21741/9781945291173-5 26 90 o Dector Bank径向准直器(5 mm宽)径向准直器(5 mm宽)-9 o te ct或B an k量规体积(5 x 5 x 10 mm m~3)规格定义狭缝(5 mm宽x 10 mm高)钢筋混凝土试件45o 105(C)110 mm(未粘结区)320 mm(粘结区)
It has been demonstrated in our past studies that neutron diffraction can be an alternative method to conventional strain gauges for measuring the stress distribution along rebar embedded in concrete. The current study investigated the possibility of the bond stress evaluation using neutron diffraction in order to find a further capability of neutron diffraction for the structural engineering study on the reinforced concrete structure. Several peaks appeared in the bond stress distribution measured by neutron diffraction, showing the inhomogeneous bond variation along the embedded rebar. This result suggests that the neutron diffraction technique with high spatial resolution makes it possible to investigate local bond resistance caused by the transverse ribs. The bond stress distribution measured by the neutron diffraction technique is expected to bring detailed understanding of the bond mechanism between rebar and concrete for the reinforced concrete structure. Introduction The reinforced concrete (RC), which is widely utilized for various architectural and civil engineering structures, is well known as a composite structure, in which concrete with relatively low tensile strength and ductility is strengthened by reinforcements such as steel rods (rebars) with high tensile strength and/or ductility. In general, quantitative evaluation of bond resistance between rebar and surrounding concrete is important to discuss the performance of the RC structures [1-4]. In our previous studies, we have investigated the potential of the neutron diffraction technique for the stress measurement of rebar embedded in concrete as an alternative method to the conventional strain gauge. Our first relevant work was carried out using the engineering diffractometer RESA-1 in JRR3 (Japan Research Reactor No. 3), and we demonstrated that the neutron diffraction technique can be a novel strain measurement method for rebar embedded in concrete [5, 6]. More recently, threedimensional deformation behavior of the embedded rebar including the axial and transverse strains was successfully measured under pull-out loading using Time-of-Flight (TOF) neutron diffraction with the engineering diffractometer, TAKUMI in MLF (Materials and life Science Experimental Facility) of J-PARC (Japan Proton Accelerator Research Complex) [7]. Furthermore, it was demonstrated by some application studies using TAKUMI that the neutron diffraction technique is available to assess the bond deterioration due to rebar corrosion and crack generation in concrete [8]. As described above, our previous studies commonly discussed on the bond condition between rebar Residual Stresses 2016: ICRS-10 Materials Research Forum LLC Materials Research Proceedings 2 (2016) 25-30 doi: http://dx.doi.org/10.21741/9781945291173-5 26 90 o Dector Bank Radial Collimator (5mm width) Radial Collimator (5mm width) -9 0 o De te ct or B an k Gauge volume (5 x 5 x 10 mm3) Gauge definition slit (5 mm width x 10 mm height) Reinforced concrete specimen 45o 10 5 5 (c) 110mm (un-bonded region) 320mm (Bonded region)