Direct Shear Behavior of Segment Precast UHPC Big Shear Key Epoxy Joints

doi:10.16552/j.cnki.issn1001-1625.2025.0939

Abstract

Abstract:

To investigate the optimal shear key depth h and shear key root height H ratio and shear key inclination angle θ in engineering design， this study conducted direct shear tests on ultra-high performance concrete （UHPC） big shear key epoxy joints to explore their shear performance and failure mechanisms. Based on the ABAQUS finite element model （FEM） validated by experiments， the influences of parameters such as lateral prestress σ， θ， and h on the failure mode， failure mechanism， and shear bearing capacity of shear key specimens were analyzed using the control variable method and orthogonal experimental design. The formula for calculating the shear bearing capacity of UHPC big shear key epoxy joints was proposed. The results show that the failure modes of the specimens are primarily categorized into direct shear failure at shear key root， slip failure along epoxy joint interface， and shear-compression failure. For engineering applications， the recommended ranges for h/H and θ are 0.19≤h/H≤0.30 and 15°≤θ≤27°， respectively. The ratio for theoretical calculation value and the FEM value with difference lateral prestress， inclination angle and shear key depth is between 0.88 to 1.14， with an average value of 0.94.

Key words: UHPC big shear key epoxy joint, direct shear behavior, shear strength, strength calculation, finite element analysis

CLC Number:

U441⁺.4

CHEN Weizhong, LI Mingyang, MAI Peng, ZHOU Xuan, LIU Xucong. Direct Shear Behavior of Segment Precast UHPC Big Shear Key Epoxy Joints[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2026, 45(4): 1459-1470.

Figures/Tables 20

Fig.1 Size and rebar of shear key epoxy joint （unit： mm）

Table 1 Test specimen parameter

Specimen No.	H/mm	h/mm	θ/（°）
B1	80	20	45
B2	160	40	27
B3	160	60	27

Fig.2 Schematic diagram of experimental test setup

Fig.3 Cracks and failure modes of specimen

Fig.4 Load-slip curves of specimen

Fig.5 FEM of ABAQUS

Fig.6 Constitutive stress σ-strain ε relationship of UHPC

Table 2 Test values and calculated values of finite element bearing capacity

Specimen No.	σ/MPa	h/mm	T/kN	L_c/kN	L_c/T
B1	3	2	308.4	314.9	1.02
B2	3	4	552.6	565.5	1.01
B3	3	6	540.0	548.0	1.02

Fig.7 Test and finite element load-slip curves

Fig.8 Failure mode of shear key

Fig.9 Finite element failure results

Fig.10 Parameters of lateral prestress

Fig.11 Finite element failure results

Fig.12 Parameters of shear key inclination angle

Fig.13 Finite element failure results

Fig.14 Parameters of shear key depth

Table 3 Orthogonal analysis of FEM parameters

No.	σ/MPa	tan θ	h/mm	L/kN
1	2	0	0	28.8
2	2	0.25	10	236.5
3	2	0.50	20	385.5
4	2	1.00	30	190.4
5	4	0	10	278.0
6	4	0.25	0	57.5
7	4	0.50	30	442.5
8	4	1.00	20	320.8
9	6	0	20	458.5
10	6	0.25	30	467.2
11	6	0.50	0	86.3
12	6	1.00	10	340.0
13	8	0	30	480.7
14	8	0.25	20	479.8
15	8	0.50	10	360.8
16	8	1.00	0	115.0

Fig.15 Influence of each parameter on shear bearing capacity

Fig.16 Direct shear failure mode of UHPC big shear key epoxy joint

Fig.17 Ratio of finite element value to theoretical calculation value

References 30

[1]	赵品，邵旭东，荣学亮，等. 节段预制拼装波形钢腹板连续组合箱梁抗弯性能试验研究［J］. 工程力学， 2024， 41（9）： 191-200.
	ZHAO P， SHAO X D， RONG X L， et al. Experimental study on flexural performance of precast segmental assembled continuous box girder with corrugated steel webs［J］. Engineering Mechanics， 2024， 41（9）： 191-200 （in Chinese）.
[2]	刘文杰，韩冰，阎武通，等. 预制拼装混凝土节段梁的结构力学性能研究进展［J］. 中国公路学报， 2023， 36（4）： 81-99.
	LIU W J， HAN B， YAN W T， et al. Review on structural mechanical performance of precast concrete segmental beam［J］. China Journal of Highway and Transport， 2023， 36（4）： 81-99 （in Chinese）.
[3]	邵旭东，邱明红，晏班夫，等. 超高性能混凝土在国内外桥梁工程中的研究与应用进展［J］. 材料导报， 2017， 31（23）： 33-43.
	SHAO X D， QIU M H， YAN B F， et al. A review on the research and application of ultra-high performance concrete in bridge engineering around the world［J］. Materials Review， 2017， 31（23）： 33-43 （in Chinese）.
[4]	蒋欣，汤大洋，胡所亭，等. 超高性能混凝土在国内外桥梁工程中的应用［J］. 铁道建筑， 2021， 61（12）： 1-7.
	JIANG X， TANG D Y， HU S T， et al. Application of ultra-high performance concrete in bridge engineering all over the world［J］. Railway Engineering， 2021， 61（12）： 1-7 （in Chinese）.
[5]	张阳，吴洁，邵旭东，等. 超高性能混凝土-普通混凝土界面抗剪性能试验研究［J］. 土木工程学报， 2021， 54（7）： 81-89.
	ZHANG Y， WU J， SHAO X D， et al. Experiment on interfacial shear properties between ultra-high performance concrete and normal strength concrete［J］. China Civil Engineering Journal， 2021， 54（7）： 81-89 （in Chinese）.
[6]	饶欣频，霍文斌，胡智敏，等. 超高性能混凝土与普通混凝土的界面抗剪性能试验研究［J］. 建筑结构， 2021， 51（14）： 101-106.
	RAO X P， HUO W B， HU Z M， et al. Experimental study on the interface shear performance of ultra-high performance concrete and normal concrete［J］. Building Structure， 2021， 51（14）： 101-106 （in Chinese）.
[7]	吴玥，张阳，刘颖峰，等. 预制UHPC与后浇NC界面的抗剪性能［J］. 铁道建筑， 2023， 63（9）： 48-53.
	WU Y， ZHANG Y， LIU Y F， et al. Experimental and numerical analysis on interfacial shear resistance of prefabricated UHPC-post-cast NC interface［J］. Railway Engineering， 2023， 63（9）： 48-53 （in Chinese）.
[8]	王鹏刚，赵明海，田砾，等. 预制键槽式UHPC与后浇混凝土界面粘结抗剪性能［J］. 复合材料学报， 2024， 41（5）： 2633-2644.
	WANG P G， ZHAO M H， TIAN L， et al. Interface shear resistance of precast key way UHPC and post-cast normal concrete［J］. Acta Materiae Compositae Sinica， 2024， 41（5）： 2633-2644 （in Chinese）.
[9]	程文强，耿健，柳根金，等. 界面处理对预制UHPC与现浇NC界面抗剪性能的影响［J］. 建筑材料学报， 2024， 27（1）： 76-83.
	CHENG W Q， GENG J， LIU G J， et al. Effect of interfacial treatment on shear properties of precast UHPC and cast-in-place NC［J］. Journal of Building Materials， 2024， 27（1）： 76-83 （in Chinese）.
[10]	TOLEDO W K， MOUSAVINEZHAD S， GONZALES G J， et al. Direct shear and direct tension bond assessment between ultra-high performance concrete and normal strength concrete［C］//Tran-SET 2022. San Antonio， Texas. American Society of Civil Engineers， 2022： 45-55.
[11]	ZHAO Y C， LEI H G， GUO L K， et al. Experimental investigation on interface performance of UHPC-strengthened NC structure through push-out tests［J］. Materials， 2023， 16（5）： 1766.
[12]	李聪，陈宝春，谢泽豪，等. 钢-UHPC组合板环氧黏结界面抗剪与抗拉性能试验［J］. 土木工程学报， 2023， 56（1）： 25-36+56.
	LI C， CHEN B C， XIE Z H， et al. Shear and tensile performance tests of epoxy bonding interface between steel and UHPC slab［J］. China Civil Engineering Journal， 2023， 56（1）： 25-36+56 （in Chinese）.
[13]	JIANG H B， HUANG C W， MEI G Y， et al. Experimental and numerical investigations on direct shear performance of UHPC dry joints［J］. Engineering Structures， 2023， 283： 115872.
[14]	HUSSEIN H H， SARGAND S M， RIKABI F TAL， et al. Experimental validation of optimized ultra-high-performance concrete shear key shape for precast pre-stressed adjacent box girder bridges［J］. Construction and Building Materials， 2018， 190： 178-190.
[15]	YU K， ZHANG Z Y， ZOU Y， et al. Interfacial shear performance of epoxy adhesive joints of prefabricated elements made of ultra-high-performance concrete［J］. Polymers， 2022， 14（7）： 1364.
[16]	潘仁胜，何伟伟，程灵霄，等. UHPC大键齿干接缝直剪性能及尺寸参数分析［J］. 湖南大学学报（自然科学版）， 2021， 48（7）： 129-137.
	PAN R S， HE W W， CHENG L X， et al. Direct shear behavior and dimensional parameter analysis of UHPC dry joint with big shear key［J］. Journal of Hunan University （Natural Sciences）， 2021， 48（7）： 129-137 （in Chinese）.
[17]	LIU T X， WANG Z， GUO J， et al. Shear strength of dry joints in precast UHPC segmental bridges： experimental and theoretical research［J］. Journal of Bridge Engineering， 2019， 24： 04018100.
[18]	CHEN L， YAN J， XIANG N L， et al. Shear performance of ultra-high performance concrete multi-keyed epoxy joints in precast segmental bridges［J］. Structures， 2022， 46： 1696-1708.
[19]	PAN R S， CHENG L X， HE W W， et al. Direct shear performance of UHPC multi-keyed epoxy joint［J］. Structures， 2022， 44： 1898-1909.
[20]	PAN R S， HE W W， CHENG L X， et al. Direct shear strength of UHPC large-keyed epoxy joint： theoretical model and experimental verification［J］. Journal of Bridge Engineering， 2022， 27（9）： 04022083.
[21]	PAN R S， HE W W， CHENG L X， et al. Experimental investigation on the shear performance of UHPC large-keyed epoxy joints subjected to direct shear loading［J］. Structures， 2023， 54： 171-182.
[22]	Association Française de Normalization. National addition to eurocode 2-design of concrete structures： specific rules for ultra-high performance fiber-reinforced concrete： NF P 18-710 ［S］. Paris， France： Association Française de Normalization， 2016.
[23]	张哲，邵旭东，李文光，等. 超高性能混凝土轴拉性能试验［J］. 中国公路学报， 2015， 28（8）： 50-58.
	ZHANG Z， SHAO X D， LI W G， et al. Axial tensile behavior test of ultra high performance concrete［J］. China Journal of Highway and Transport， 2015， 28（8）： 50-58 （in Chinese）.
[24]	杨剑，方志. 预应力超高性能混凝土梁的受弯性能研究［J］. 中国公路学报， 2009， 22（1）： 39-46.
	YANG J， FANG Z. Research on flexural behaviors of prestressed ultra high performance concrete beams［J］. China Journal of Highway and Transport， 2009， 22（1）： 39-46 （in Chinese）.
[25]	袁爱民，符俊冬，程磊科，等. 节段预制桥梁胶接缝配筋剪力键剪切性能试验［J］. 中国公路学报， 2018， 31（12）： 81-87.
	YUAN A M， FU J D， CHENG L K， et al. Experiment of shear performance of epoxy resin joints with reinforced keys in precast concrete segmental bridge［J］. China Journal of Highway and Transport， 2018， 31（12）： 81-87 （in Chinese）.
[26]	BUYUKOZTURK O， BAKHOUM M M， MICHAEL BEATTIE S. Shear behavior of joints in precast concrete segmental bridges［J］. Journal of Structural Engineering， 1990， 116（12）： 3380-3401.
[27]	AASHTO. Guide specifications for the design and construction of segmental concrete bridges： I SBN 156051-275-X ［S］. Washington： AASHTO， 2003.
[28]	GOPAL B A， HEJAZI F， HAFEZOLGHORANI M， et al. Shear strength of dry and epoxy joints for ultra-high-performance fiber-reinforced concrete［J］. ACI Structural Journal， 2020， 117（1）： 279-288.
[29]	潘仁胜，程灵霄，何伟伟，等. UHPC键齿胶接缝直剪性能试验研究［J］. 土木工程学报， 2022， 55（11）： 38-49+117.
	PAN R S， CHENG L X， HE W W， et al. Experimental research on direct shear performance of UHPC keyed epoxy joints［J］. China Civil Engineering Journal， 2022， 55（11）： 38-49+117 （in Chinese）.
[30]	李兴焮. 节段预制拼装UHPC箱梁接缝构造形式及力学性能研究［D］. 长沙：湖南大学， 2021.
	LI X X. Research on structural types and mechanical properties of joints in precast UHPC segmental box girder［D］. Changsha： Hunan University， 2021 （in Chinese）.