超高性能RPC钢筋网加固混凝土界面粘结性能试验研究

卜良桃; 徐博煜

doi:10.6052/j.issn.1000-4750.2021.06.0469

超高性能RPC钢筋网加固混凝土界面粘结性能试验研究

doi: 10.6052/j.issn.1000-4750.2021.06.0469

卜良桃^,,
徐博煜

湖南大学土木工程学院，湖南，长沙 410082

基金项目: 中国工程建设标准化协会资助项目：活性粉末混凝土高强钢筋网薄层加固混凝土结构技术规程项目(建标协字[2019]22号)

详细信息

作者简介:
徐博煜(1997−)，女，浙江衢州人，硕士生，主要从事工程结构加固技术研究(E-mail: xuby127@163.com)

通讯作者:
卜良桃(1963−)，男，湖南南县人，教授，博士，主要从事工程结构加固技术研究(E-mail: plt63@126.com)

中图分类号: TU398
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- HTML全文浏览量: 72
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- 被引次数: 0
出版历程
- 收稿日期: 2021-06-23
- 录用日期: 2021-12-14
- 修回日期: 2021-12-07
- 网络出版日期: 2021-12-14
- 刊出日期: 2022-11-01

EXPERIMENTAL STUDY ON INTERFACIAL BONDING PERFORMANCE OF REACTIVE POWDER CONCRETE STRENGTHENED WITH BAR MESH

BU Liang-tao^,,
XU Bo-yu

College of Civil Engineering, Hunan University, Changsha, Hu’nan 410082, China

摘要

摘要: 针对现有混凝土加固技术导致的耐久性弱、承载力低的问题，该文基于活性粉末混凝土钢筋网加固混凝土技术(Technical for strengthening concrete structures with reactive powder concrete and bar mesh, RPCBM)，展开了双面剪切试验。该文评估了各试件的抗剪强度、破坏形态与荷载位移曲线，系统性地探讨了粗糙度、植筋率、钢筋网规格对RPCBM加固旧混凝土结构界面剪切性能的影响。结果表明：RPCBM加固混凝土结构的界面抗剪强度和延性提升幅度较大，具有良好的粘结性能。在一定范围内，随着粗糙度增大，粘结界面抗剪强度提高；植筋率增高，抗剪强度与延性增强；钢筋网规格是改善界面延性的重要因素。在此基础上，为了更好地计算RPCBM加固混凝土的界面粘结强度，该文基于以上数据建立了粘结界面抗剪强度的模型，提出了综合计算RPCBM加固普通混凝土(Ordinary Concrete, OC)界面抗剪强度的公式，试验结果与理论分析吻合较好，为工程实践中加固材料的选择和改进施工方法提供了理论依据。
- 活性粉末混凝土 /
- 界面粘结性能 /
- 粗糙度 /
- 植筋率 /
- 钢筋网规格
Abstract: To solve the problems of weak durability and low bearing capacity of current concrete strengthening technology, double shear tests were conducted based on the technical for strengthening concrete structures with reactive powder concrete and bar mesh (RPCBM). The shear strength, failure mode and load-displacement curve of each specimen were evaluated, and the effects of roughness, pin rate and bar mesh specification on the interfacial stress strength of RPCBM reinforced old concrete structure were discussed . The results show that the shear strength and ductility of RPCBM reinforced concrete structure are greatly improved, and the interface has good bonding performance. Within a certain range, the shear strength of bonding interface increases with the increase of roughness; the shear strength and ductility increase with the increase of pin rate. In addition, the bar mesh specification is an important factor for improving the interface ductility. The shear strength model of bonding interface was established to calculate the interface bond strength of RPCBM reinforced concrete. The shear strength formula of RPCBM reinforced ordinary concrete (OC) interface was proposed, and the test results were consistent with the theoretical analysis, which provides a theoretical basis for the selection of reinforcement materials and improvement of construction methods in engineering practice.
- reactive powder concrete /
- interfacial bonding performance /
- roughness /
- pin rate /
- bar mesh specification

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图 1 双面剪切试验RPCBM-OC组合棱柱体图

Figure 1. Composite diagram of RPCBM-OC prism components in Double shear test

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图 2 双面剪切试验加载示意图

Figure 2. Double shear test setup and loading scheme

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图 3 不同测试组的破坏形态

Figure 3. Failure modes of different test groups

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图 4 双面剪切构件的荷载-位移曲线

Figure 4. Load-interfacial slip curves of push-out specimens

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图 5 RPCBM-OC界面抗剪机制

Figure 5. Shear resistance mechanisms of RPCBM-OC interfaces

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图 6 RPCBM-OC界面抗剪强度实测值与公式计算值对比图

Figure 6. Comparison of measured and calculated shear strength of RPCBM-OC interface

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表 1 试验分组

Table 1. Testing matrix

分组编号	加固层钢筋网规格/ (mm×mm)	粗糙度等级	销钉根数/根	分组编号	加固层钢筋网规格/ (mm×mm)	粗糙度等级	销钉根数/根
A-0-0	无	A级粗糙度：表面不做处理，光滑表面R_t<1.5 mm	0	B-50-8	网格50	(灌砂法测得约 1.0 mm~3.0 mm)	8
A-0-18	无		18	B-75-8	网格75		8
A-0-9	无(100半锚)		9	B-100-18	网格100		18
A-0-8	无		8	B-100-9	网格100(半锚)		9
A-50-18	网格50		18	C-0-0	无	C级粗糙度：深度凿毛，可以看到90%以上的粗骨料，非常粗糙表面R_t≥3.0 mm(测得约3.2 mm~6.2 mm)	0
A-50-8	网格50		8	C-0-18	无		18
A-75-8	网格75		8	C-0-9	无(100半锚)		9
A-100-18	网格100		18	C-0-8	无		8
A-100-9	网格100(半锚)		9	C-50-18	网格50		18
B-0-0	无	B级粗糙度：轻度凿毛约30%至50%的粗骨料可见，粗糙度R_t≥1.5 mm	0	C-50-8	网格50		8
B-0-18	无		18	C-75-8	网格75		8
B-0-9	无(100半锚)		9	C-100-18	网格100		18
B-0-8	无		8	C-100-9	网格100(半锚)		9
B-50-18	网格50		18	−	−	−	−

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表 2 OC和RPC基本力学性能指标

Table 2. Basic mechanical properties of OC and RPC

强度等级	立方体抗压强度/MPa	立方体劈裂抗拉强度/MPa	轴心抗压强度/MPa	弹性模量/GPa
C40	46.8	2.9	−	33.5
RPC100	138.0	−	118.0	47.6

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表 3 钢材基本力学性能指标

Table 3. Basic mechanical properties of steel

钢筋种类	钢筋直径/mm	钢筋屈服强度/MPa	弹性模量/MPa
HRB400	6.0	472.5	2.2

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表 4 试验荷载下的结果

Table 4. Characteristic values of testing loads and failure parameters for push-out tests

分组编号	构件双面剪切试验开裂荷载P_cr/kN	构件破坏荷载P_u/kN	构件双面试验抗剪强度Τ_u/MPa	极限荷载时的滑移值S_u/mm	植筋率ρ	P_cr/P_u/(%)	最大距离 D/cm	面积比 C/B/(%)	破坏形态
A-0-0	354.32	860	2.39	0.09	−	41.2	1.1	7	A
A-0-18	781.20	1700	4.72	1.35	0.0057	46.0	9.1	25	BMA
A-0-9	549.12	1180	3.28	1.11	0.0028	46.5	3.1	18	BMA
A-0-8	562.32	1220	3.39	0.55	0.0025	46.1	2.6	17	BMA
A-50-18	752.56	1840	5.11	1.41	0.0057	40.9	20.7	90	TMA
A-50-8	597.64	1220	3.39	1.39	0.0025	49.0	4.6	18	CMA
A-75-8	582.12	1200	3.33	1.14	0.0025	48.6	11.0	23	CMA
A-100-18	738.92	1660	4.61	1.27	0.0057	44.5	19.2	67	CMA
A-100-9	587.40	1200	3.33	1.13	0.0028	49.0	14.6	27	CMA
B-0-0	604.50	1280	3.56	0.74	−	47.2	8.4	86	CMA
B-0-18	938.00	2360	6.56	1.11	0.0057	39.7	11.3	80	BMA
B-0-9	851.84	1600	4.44	0.89	0.0028	53.3	11.5	71	BMA
B-0-8	828.24	1580	4.39	0.65	0.0025	52.4	9.6	16	BMA
B-50-18	962.56	2300	6.39	1.19	0.0057	41.8	11.8	72	TMA
B-50-8	910.80	1620	4.50	1.18	0.0025	56.2	7.6	30	CMA
B-75-8	886.44	1600	4.44	1.16	0.0025	55.5	7.4	83	CMA
B-100-18	952.00	2440	6.78	1.26	0.0057	39.0	13.5	88	TMA
B-100-9	917.44	1880	5.22	1.31	0.0028	48.8	6.9	79	CMA
C-0-0	764.56	1520	4.22	0.76	−	50.3	8.5	50	CMA
C-0-18	1007.98	2340	6.50	1.34	0.0057	43.1	12.6	80	TMA
C-0-9	907.92	1860	5.17	0.91	0.0028	48.8	23.9	96	TMA
C-0-8	1026.48	1860	5.17	0.96	0.0025	55.2	9.8	94	TMA
C-50-18	1098.24	2680	7.44	1.48	0.0057	41.0	11.3	78	TMA
C-50-8	944.78	1940	5.39	0.92	0.0025	48.7	10.6	97	TMA
C-75-8	910.10	1900	5.28	1.03	0.0025	47.9	15.6	100	TMA
C-100-18	1041.48	2580	7.17	1.39	0.0057	40.3	13.5	96	TMA
C-100-9	904.04	1940	5.39	1.06	0.0028	46.6	16.4	80	TMA
注：D/cm为剪切破坏面与同侧加固层外表面之间的最大距离；C/B/(%)为附着在RPC表面的普通混凝土与整个粘结界面的面积比。

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表 5 OC-OC界面抗剪强度的典型计算公式

Table 5. Typical calculating models for the shear strength of OC-OC interface

规范	抗剪强度计算公式
ACI 318-08(2008)^[22]	${V_{\rm u}} = {A_{ {\textit{ν}} f} }{f_{\rm y}}\mu$
AASHTO LRFD Bridge Design Specifications (2010)^[23]	${V_{\rm u}} = c{A_{\rm c{\textit{ν}} } } + \mu {A_{{\textit{ν}}\rm f} }{f_{\rm y}}$
CAN/CSA-S6-00(2000)^[24]	${V_{\rm u}} = {\varphi }_{\rm c} {A}_{\rm c{\textit{ν}} }(c+\mu \rho {f}_{\rm y})$
水泥复合砂浆钢筋网加固混凝土结构技术规程CECS 242−2016^[25]	${V_{\rm u}} = {k_1}{k_2}{f_{\rm c}}{A_{\rm c{\textit{ν}} } } + nf{\gamma _{\rm b}}{W_{\rm x}}/{L_{\rm b}}$
Fib Model Code for CoOCrete Structures (2010)^[26]	${V_{\rm u}} = {\text{A} }_{\rm c{\textit{ν}} }(\text{c}+\mu \rho {\kappa }_{1}{f}_{\rm y}+{\kappa }_{2}\rho \sqrt{ {f}_{\rm y}{f}_{\rm c } })$
注：${A_{\rm {\textit{ν}} f} }$为抗剪钢筋面积；${f_{\rm {y} } }$为抗剪钢筋屈服强度；$\mu $为摩擦系数；c为界面粘聚力；${A_{ {\rm {c} }{\textit{ν}} } }$为新老混凝土界面面积；$\rho $为抗剪钢筋配筋率；${\kappa _1}$，${\kappa _2}$为相互作用系数；${f_{\rm c}}$为混凝土轴心抗压强度设计值；k₁为混凝土强度影响系数；k₂为界面销钉分布影响系数；${\phi _{\text{c}}}$为强度折减系数；n为构件剪切销钉根数(剪切销钉均匀分布)；γ_b为截面塑性发展系数；W_x为单根销钉净截面抗弯模量；L_b为销钉的外露长度。

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表 6 系数K₁、K₂、α的值

Table 6. Values for K₁, K₂ and α coeffificients

界面类型	K₁	K₂	α
A级粗糙度	1.8327	0.3978	1.0
B级粗糙度	0.3558	1.7056	1.5
C级粗糙度	0.1898	1.3534	1.8

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表 7 RPCBM-OC界面抗剪强度实测值与计算值对比

Table 7. Comparison of measured and calculated shear strength of RPCBM-OC interface

编号	实测值	计算值	误差/(%)	编号	实测值	计算值	误差/(%)
A-0-0	2.39	2.00	16.3	B-50-8	4.50	4.63	2.0
A-0-18	4.72	4.54	4.0	B-75-8	4.44	4.63	−1.6
A-0-9	3.28	3.09	5.7	B-100-18	6.78	6.04	7.9
A-0-8	3.39	3.13	7.7	B-100-9	5.22	4.59	12.1
A-50-18	5.11	4.54	11.2	C-0-0	4.22	4.00	5.3
A-50-8	3.39	3.13	7.7	C-0-18	6.50	6.54	−0.5
A-75-8	3.33	3.13	6.2	C-0-9	5.17	5.09	1.5
A-100-18	4.61	4.54	1.6	C-0-8	5.17	5.15	0.8
A-100-9	3.33	3.09	7.3	C-50-18	7.44	6.54	12.2
B-0-0	3.56	3.50	1.6	C-50-8	5.39	5.15	4.8
B-0-18	6.56	6.04	5.5	C-75-8	5.28	5.15	2.8
B-0-9	4.44	4.59	−3.3	C-100-18	7.17	6.54	8.8
B-0-8	4.39	4.63	−5.4	C-100-9	5.39	5.09	5.5
B-50-18	6.78	6.39	5.7	−	−	−	−

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