Huang Jinlin, He Zhiying, Khan Muhammad Basit Ehsan, Zheng Xiaohong, Luo Zhibin
School of Water Conservancy and Civil Engineering, South China Agriculture University, Guangzhou, 510642, China.
School of Civil Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.
Sci Rep. 2021 Sep 24;11(1):19069. doi: 10.1038/s41598-021-98502-x.
Heat treatment is often required for ultra-high-performance concrete (UHPC) to achieve high strength. To broad its use in construction, the effect of different curing conditions on the properties of UHPC has been developed for many years. The experimental investigation of large scale ultra-high-performance fibre reinforced concrete (UHPFRC) beams is limited. In the present study, UHPFRC specimens and concrete cured at 20 °C were prepared to investigate the properties and flexural behaviour. The standard cubic compressive strength of UHPFRC specimens cannot be achieved at curing temperature of 20 °C. The bearing capacity under flexure was enhanced with the increase of reinforcement ratio. The failure modes of beams changed from ductile to brittle as the reinforcement ratio increased from 1.26 to 9.50%. The flexural behaviour of UHPFRC beams cured at room temperature was in accordance with the UHPFRC beams cured at high temperature in previous studies. In addition, the calculation model of CECS38-2004 underestimated the bending moment capacity of the under-reinforced UHPFRC beams (with reinforcement ratio from 0 to 7.85%) and overestimated the bending moment capacity of the UHPFRC beams with high reinforcement ration of 9.50%.
超高性能混凝土（UHPC）通常需要进行热处理以实现高强度。为了扩大其在建筑中的应用，多年来一直在研究不同养护条件对UHPC性能的影响。大规模超高性能纤维增强混凝土（UHPFRC）梁的试验研究有限。在本研究中，制备了UHPFRC试件和在20℃养护的混凝土，以研究其性能和弯曲行为。在20℃养护温度下，UHPFRC试件无法达到标准立方体抗压强度。随着配筋率的增加，梁的抗弯承载力提高。随着配筋率从1.26%增加到9.50%，梁的破坏模式从延性转变为脆性。室温养护的UHPFRC梁的弯曲行为与先前研究中高温养护的UHPFRC梁一致。此外，CECS38 - 2004计算模型低估了低配筋率（配筋率从0到7.85%）的UHPFRC梁的弯矩承载力，高估了配筋率为9.50%的UHPFRC梁的弯矩承载力。
