Khan Mohammad Iqbal, Abbas Yassir M
Department of Civil Engineering, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia.
Materials (Basel). 2023 Jun 29;16(13):4695. doi: 10.3390/ma16134695.
In the literature, there is little information available regarding the behavior of composite beams made up of reinforced concrete (RC) and ultra-ductile fiber-reinforced concrete (UDFRC). In this study, UDFRC was examined for its effectiveness in enhancing the strength of RC beams. With a tensile strength of 4.35 MPa and a strain capacity of 2.5%, PVA-based UDFRC was prepared. The performance of 12 medium-sized reinforced concrete (RC) beams was measured under four-point flexural loading. The beams measured 1800 mm long, 150 mm wide, and 200-260 mm deep. The experimental program on beam specimens was divided into two phases. In the first, four 150 × 200 × 1800 mm RC beams with UDFRC layer thicknesses of 0, 30, 60, and 90 mm were tested. Additionally, four concrete and four concrete-UDFRC beams were investigated, measuring 150 × 230 × 1800 mm and 150 × 260 × 1800 mm, respectively. The study focused on medium-sized, slender RC beams under quasi-static loads and room temperature with additional or substituted UDFRC layers. As a result of replacing concrete with UDFRC, the load-carrying capacity at first crack and steel yield significantly increased between 18.4 and 43.1%, but the ultimate load-carrying capacity increased only in the range of 6.3-10.8%. Furthermore, beams with additional UDFRC layers could carry 30-50% more load than their concrete counterparts. An RC-UDFRC beam had a load-carrying capacity 10-15% greater than that of a comparable RC beam. Generally, there is a lower deflection response in UDFRC-concrete composite RC beams than in control concrete beams. The UDFRC layering can potentially improve the load-carrying capacity of RC beams, at least when ductility provisions are considered.
在文献中，关于由钢筋混凝土（RC）和超延性纤维增强混凝土（UDFRC）组成的组合梁的性能，可获取的信息很少。在本研究中，对UDFRC增强RC梁强度的有效性进行了研究。制备了抗拉强度为4.35MPa、应变能力为2.5%的基于聚乙烯醇的UDFRC。在四点弯曲加载下测量了12根中型钢筋混凝土（RC）梁的性能。这些梁长1800mm、宽150mm、深200 - 260mm。梁试件的试验方案分为两个阶段。第一阶段，测试了4根150×200×1800mm的RC梁，其UDFRC层厚度分别为0、30、60和90mm。此外，还研究了4根混凝土梁和4根混凝土 - UDFRC梁，尺寸分别为150×230×1800mm和150×260×1800mm。该研究聚焦于在准静态荷载和室温下，带有附加或替代UDFRC层的中型细长RC梁。用UDFRC替代混凝土后，初裂和钢筋屈服时的承载能力显著提高了18.4%至43.1%，但极限承载能力仅提高了6.3% - 10.8%。此外，带有附加UDFRC层的梁比其对应的混凝土梁能多承受30% - 50%的荷载。RC - UDFRC梁的承载能力比同类RC梁高10% - 15%。一般来说，UDFRC - 混凝土组合RC梁的挠度响应比对照混凝土梁低。UDFRC分层至少在考虑延性规定时，有可能提高RC梁的承载能力。
