Steel-free hybrid reinforcing bars for concrete structures
Steel-free hybrid reinforcing bars for concrete structures
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DOI：
10.1177/1369433218818772
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发表时间：
2018-12
影响因子：
2.6
通讯作者：
J. Teng;Bing Zhang;Shishun Zhang;B. Fu
中科院分区：
文献类型：
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作者：
J. Teng;Bing Zhang;Shishun Zhang;B. Fu
人们对用纤维增强聚合物钢筋替代钢筋进行了广泛的研究，以消除传统钢筋混凝土结构中的钢筋腐蚀问题。然而，由于纤维增强聚合物钢筋的压缩性能（由于纤维微屈曲等问题）远低于拉伸性能，因此通常不建议在混凝土柱中使用它们；当需要无钢结构时，这构成了重大挑战。本文介绍了香港理工大学开发的一种新型无钢混合钢筋，它克服了上述问题。这种混合钢筋通常由中心纤维增强聚合物钢筋、外部纤维增强聚合物限制管和高强度水泥材料（例如超高性能混凝土）的环形层组成。为了展示这些混合钢筋的性能，本文介绍了一系列初步测试和相关建模工作的结果。这些结果表明：(1) 中心的纤维增强聚合物钢筋得到了良好的支撑，以抵抗钢筋屈曲和纤维微屈曲，(2) 纤维增强聚合物材料的抗压强度可以得到充分调动，(3) 混合钢筋的应力应变响应可以设计为类似于具有一定屈服后硬化的弹塑性响应。
Extensive research has been conducted on the replacement of steel rebars with fibre-reinforced polymer rebars to eliminate the steel corrosion problem in conventional steel bar–reinforced concrete structures. However, as the performance of fibre-reinforced polymer rebars is substantially inferior in compression (due to issues such as fibre micro-buckling) than in tension, their use in concrete columns is generally not recommended; this poses a significant challenge when a steel-free structure is needed. This article presents a novel steel-free hybrid rebar developed at The Hong Kong Polytechnic University that overcomes the above-mentioned problem. Such a hybrid rebar typically consists of a central fibre-reinforced polymer rebar, an external fibre-reinforced polymer confining tube and an annular layer of high-strength cementitious material such as ultrahigh-performance concrete. To demonstrate the performance of these hybrid rebars, results from a series of preliminary tests and associated modelling work are presented in the article. These results indicate that (1) the fibre-reinforced polymer rebar at the centre is well supported against bar buckling and fibre micro-buckling, (2) the compressive strength of the fibre-reinforced polymer material can be fully mobilized and (3) the stress–strain response of hybrid rebars can be designed to resemble an elastic–plastic response with some post-yielding hardening.