不同类型荷载作用下UHPC中钢筋搭接性能试验研究

Experimental study on the performance of lap-spliced steel bars in UHPC under different types of loads

摘要

为明确荷载作用类型对超高性能混凝土(ultra-high performance concrete，UHPC)中带肋钢筋搭接连接受力性能的影响，以荷载作用类型(单调、重复和往复加载)以及UHPC中的钢纤维体积掺量(1%、2%和3%)为试验参数，对UHPC中带肋钢筋搭接连接试件进行了加载试验，获得了各试验参数对UHPC中带肋钢筋搭接连接性能的影响规律。结果表明，所有试件均发生UHPC保护层劈裂后的钢筋拔出破坏，试件表面劈裂裂缝的发展主要与UHPC中的钢纤维掺量有关，荷载形式的影响较小；搭接黏结强度随钢纤维掺量的增加而提高且不同类型荷载作用下的提高幅度相近，钢纤维体积掺量从1%增加至2%和3%时，单调、重复和往复荷载作用下的搭接黏结强度分别提高25.25%和29.16%、17.59%和26.78%以及19.45%和30.85%；重复和往复荷载作用下的搭接黏结强度均较单调荷载作用下的黏结强度有所退化，且不同钢纤维掺量下的退化程度相近，即黏结强度退化系数基本不受钢纤维体积掺量变化的影响，并建议分别取值为0.90和0.85。基于本文试验结果，参考既有文献公式，提出了考虑钢纤维掺量及荷载类型影响的UHPC中带肋钢筋搭接黏结强度及临界搭接长度计算公式，并以本文和文献中的试验结果验证了其适用性。其他条件相同时，重复和往复荷载作用下钢筋的最小搭接长度应分别较单调荷载下的最小搭接长度增加10%和20%。

Abstract

In order to elucidate the influence of loading type on the mechanical performance of rebar splices with ribbed reinforcement embedded in ultra-high performance concrete (UHPC), a series of experiments were conducted using test parameters including loading types (monotonic, cyclic, and reverse loading) and steel fiber volume fractions (1%, 2%, and 3%). The objective was to determine the effects of these parameters on the load-bearing performance of the rebar splices in UHPC through controlled loading tests. The results show that for all the specimens, the failure mode is the pull-out of the reinforcing bars after the splitting of the UHPC protective layer. The development of the splitting cracks on the surface of the specimens is mainly related to the content of steel fibers in the UHPC, and the influence of the load form is relatively small. The lap bond strength increases with the increase of the steel fiber content, and the increase amplitudes under different types of loads are similar. When the volume content of steel fibers increases from 1% to 2% and 3%, the lap bond strengths under monotonic, cyclic and reverse loads increase by 25.25% and 29.16%, 17.59% and 26.78%, and 19.45% and 30.85% respectively. The lap bond strengths under cyclic and reverse loads are both degraded compared with that under monotonic loading, and the degradation degrees under different steel fiber contents are similar. The bond strength degradation coefficient is basically not affected by the change of the volume content of steel fibers, and it is recommended to take the values of 0.90 and 0.85 respectively. Based on the test results of this paper and referring to the formulas in existing literatures, the calculation formulas for the lap bond strength and the critical lap length of the ribbed reinforcing bars in UHPC considering the influence of the steel fiber content and the load type are proposed, and their applicability is verified by the test results in this paper and the literatures. When other conditions are the same, the minimum lap length of steel bars under cyclic and reverse loads should be increased by 10% and 20% respectively compared with that under monotonic loading.

关键词

超高性能混凝土 / 带肋钢筋 / 单调荷载 / 往复荷载 / 重复荷载 / 搭接黏结性能

Key words

ultra-high performance concrete (UHPC) / ribbed steel bars / monotonic loading / reverse loading / cyclic loading / lap-spliced bonding behavior

参考文献

[1] 方志, 郑文杰, 胡锐, 等 . 超高性能混凝土拉压滞回本构模型[J]. 地震工程与工程振动, 2023, 43(4): 81-96.

[2] FANG Zhi, ZHENG Wenjie, HU Rui, et al. Tensile and compressive hysteretic constitutive model of ultra-high performance concrete[J]. Earthquake Engineering and Engineering Dynamics, 2023, 43(4): 81-96. (in Chinese)

[3] STURM A B, VISINTIN P . Local bond slip behavior of steel reinforcing bars embedded in ultra high performance fibre reinforced concrete[J]. Structural Concrete, 2019, 20(1): 108-122.

[4] YANG J, CHEN B C, SU J Z, et al. Effects of fibers on the mechanical properties of UHPC: A review[J]. Journal of Traffic and Transportation Engineering (English Edition), 2022, 9(3): 363-387.

[5] 胡翱翔, 梁兴文, 于婧, 等 . 超高性能混凝土轴心受拉力学性能试验研究[J]. 湖南大学学报(自然科学版), 2018, 45(9): 30-37.

[6] HU Aoxiang, LIANG Xingwen, YU Jing, et al. Experimental study of uniaxial tensile characteristics of ultra-high performance concrete[J]. Journal of Hunan University (Natural Sciences), 2018, 45(9): 30-37. (in Chinese)

[7] 郑文忠, 吕雪源 . 活性粉末混凝土研究进展[J]. 建筑结构学报, 2015, 36(10): 44-58.

[8] ZHENG Wenzhong, LV Xueyuan . Literature review of reactive powder concrete[J]. Journal of Building Structures, 2015, 36(10): 44-58. (in Chinese)

[9] FEHLING E, LORENZ P, LEUTBECHER T . Experimental investigations on anchorage of rebars in UHPC[C]// Proceedings of Hipermat 2012 3rd International Symposium on UHPC and Nanotechnology for High Performance Construction Materials. Kassel, Germany: Kassel University Press, 2012: 533-540.

[10] KHAKSEFIDIS, GHALEHNOVI M, DE BRITO J . Bond behaviour of high-strength steel rebars in normal (NSC) and ultra-high performance concrete (UHPC)[J]. Journal of Building Engineering, 2021, 33: 101592.

[11] DU J, MENG W N, KHAYAT K H, et al. New development of ultra-high-performance concrete (UHPC)[J]. Composites Part B: Engineering, 2021, 224: 109220.

[12] 章萍 . 反复荷载下钢筋与高性能混凝土粘结本构关系的试验研究[D]. 上海: 同济大学, 2003.

[13] ZHANG Ping . Experimental investigation on the bond of reinforcing bars in high performance concrete under cyclic loading[D]. Shanghai: Tongji University, 2003. (in Chinese)

[14] VIEITO I, HERRADOR M F, MARTÍNEZ-ABELLA F, et al. Proposal and assessment of an efficient test configuration for studying lap splices in reinforced concrete[J]. Engineering Structures, 2018, 165: 1-10.

[15] 方志, 陈潇, 张门哲, 等 . 活性粉末混凝土中带肋钢筋搭接性能试验研究[J]. 土木工程学报, 2019, 52(3): 20-28, 49.

[16] FANG Zhi, CHEN Xiao, ZHANG Menzhe, et al. Experimental study on performance of lap-spliced ribbed steel bars in reactive powder concrete[J]. China Civil Engineering Journal, 2019, 52(3): 20-28, 49. (in Chinese)

[17] 马福栋, 邓明科, 孙宏哲, 等 . 变形钢筋/超高性能混凝土搭接黏结性能[J]. 复合材料学报, 2021, 38(11): 3912-3924.

[18] MA Fudong, DENG Mingke, SUN Hongzhe, et al. Bond behavior of deformed steel bars lap-splice in ultra high performance concrete[J]. Acta Materiae Compositae Sinica, 2021, 38(11): 3912-3924. (in Chinese)

[19] MA F D, DENG M K, FAN H K, et al. Study on the lap-splice behavior of post-yield deformed steel bars in ultra high performance concrete[J]. Construction and Building Materials, 2020, 262: 120611.

[20] LAGIER F, MASSICOTTE B, CHARRON J P . Bond strength of tension lap splice specimens in UHPFRC[J]. Construction and Building Materials, 2015, 93: 84-94.

[21] LAGIER F, MASSICOTTE B, CHARRON J P . Experimental investigation of bond stress distribution and bond strength in unconfined UHPFRC lap splices under direct tension[J]. Cement and Concrete Composites, 2016, 74: 26-38.

[22] 郭保第, 丁然, 李玥一, 等 . 钢筋在超高性能混凝土中的锚固与搭接性能试验研究[J]. 建筑结构学报, 2024, 45(9): 100-112.

[23] GUO Baodi, DING Ran, LI Yueyi, et al. Test study on anchorage and lap splicing performance of rebars in UHPC[J]. Journal of Building Structures, 2024, 45(9): 100-112. (in Chinese)

[24] 熊二刚, 谢裕鹏, 于佳仝, 等 . 超高性能混凝土中交错搭接钢筋黏结性能试验及理论研究[J]. 土木工程学报, 2026, 59(3): 72-83.

[25] XIONG Ergang, XIE Yupeng, YU Jiatong, et al. Experimental and theoretical study on bond performance of staggered lap splice rebars in ultra-high performance concrete[J]. China Civil Engineering Journal, 2026, 59(3): 72-83. (in Chinese)

[26] TEPFERS R . Cracking of concrete cover along anchored deformed reinforcing bars[J]. Magazine of Concrete Research, 1979, 31(106): 3-12.

[27] GONG Y Z, WANG Z Q, HUANG B R, et al. Experimental study on the performance of lap-spliced steel bars in ultrahigh-performance concrete[J]. Journal of Materials in Civil Engineering, 2024, 36: 04023519.

[28] 黄俊 . 疲劳及单调荷载下UHPC中搭接钢筋粘结性能试验研究[D]. 长沙: 中南大学, 2023.

[29] HUANG Jun . Experimental study on bonding behavior of lapped reinforcement in UHPC under monotonic and fatigue loads[D]. Changsha: Central South University, 2023. (in Chinese)

[30] T/CBMF 37-2018, T/CCPA 7-2018 超高性能混凝土基本性能与试验方法[S]. 北京: 中国建材工业出版社, 2018.

[31] T/CBMF 37-2018, T/CCPA 7-2018 Fundamental characteristics and test methods of ultra-high performance concrete[S]. Beijing: China Building Material Industry Publishing House, 2018. (in Chinese)

[32] 刘昱廷 . HRB600级钢筋在UHPC-CA中的搭接性能研究[D]. 宜昌: 三峡大学, 2023.

[33] LIU Yuting . Research on the lapping performance of HRB600 steel bars in coarse aggregate ultra-high performance concrete[D]. Yichang: China Three Gorges University, 2023. (in Chinese)

[34] 黄柏蓉 . 超高性能混凝土中钢筋搭接连接性能试验研究[D]. 长沙: 中南大学, 2022.

[35] HUANG Borong . Experimental study on the performance of lap-spliced reinforcement in ultra-high performance concrete[D]. Changsha: Central South University, 2022. (in Chinese)

基金资助

国家自然科学基金项目(51878262)

国家自然科学基金项目(52478312)