Value vs. Glamour: Bond Performance

2008 ◽  
Author(s):  
Brandes Institute
Keyword(s):  
Bond Performance

scholarly journals Early-Age Tensile Bond Characteristics of Epoxy Coatings for Underwater Applications

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 757 ◽  
Author(s):  
Kim ◽  
Hong ◽  
Han ◽  
Kim
Keyword(s):  
Bond Strength ◽  
Surface Treatment ◽  
Epoxy Resin ◽  
Coating Thickness ◽  
Experimental Results ◽  
Early Age ◽  
Curing Time ◽  
Bond Performance ◽  
Coating Type ◽  
Bond Characteristics

In this study, coating equipment for the effective underwater repair of submerged structures was developed. The tensile bond characteristics of selected epoxy resin coatings were investigated by coating the surface of a specimen using each of the four types of equipment. Using the experimental results, the tensile bond strength and the coating thickness were analyzed according to the type of equipment, coating, and curing time. The results show that the type of coating equipment used had the greatest effect on the measured bond strength and coating thickness of the selected coatings. However, the effect of coating type and curing time on the bond strength and the thickness was observed to be insignificant. Compared with the developed equipment, the surface treatment of the coating was observed to be more effective when using the pre-existing equipment, and thus the bond performance of the coating was improved compared to using the pre-existing equipment. Based on the experimental results, improvements and needs involving the equipment for further research were discussed.

scholarly journals Research on bond–slip performance between pultruded glass fiber-reinforced polymer tube and nano-CaCO3 concrete

2020 ◽  
Vol 9 (1) ◽  
pp. 637-649 ◽  
Author(s):  
Zhan Guo ◽  
Qingxia Zhu ◽  
Wenda Wu ◽  
Yu Chen
Keyword(s):  
Bond Strength ◽  
Concrete Strength ◽  
Fiber Reinforced Polymer ◽  
Glass Fiber Reinforced Polymer ◽  
Bond Slip ◽  
Ordinary Concrete ◽  
Bond Performance ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Push Out

AbstractThe article describes an experimental study on the bond–slip performance between the pultruded glass fiber-reinforced polymer (GFRP) tube and the nano-CaCO3 concrete. Taking the nano-CaCO3 concrete strength and GFRP tube thickness as primary parameters, nine specimens were designed and tested to study the influence of these parameters on the bond strength of the specimens. Besides, three specimens filled with the ordinary concrete were also tested by using the push-out tests to make comparisons with the bond performance of the specimens filled with nano-CaCO3 concrete. A total of four push-out tests were conducted on each specimen. The experimental results indicate that there are two types of axial load–slip curves for each specimen in four push-out tests. Moreover, comparison of the results of the push-out tests in the same direction shows that the bond failure load of the specimen decreases with the increase in the number of push-out tests. Based on the analysis of the test results, it is shown that the bond performance between the GFRP tube and the nano-CaCO3 concrete is better than that between the GFRP tube and the ordinary concrete. Furthermore, as the nano-CaCO3 concrete strength increases, the bond strength of the specimens decreases, indicating that the concrete strength has a negative effect on the bond strength. When the nano-CaCO3 concrete strength is relatively smaller (C20), the bond strength of the specimens decreases with the increase in the thickness of the GFRP tube. However, when the nano-CaCO3 concrete strength is relatively larger (C30 and C40), the bond strength of the specimens increases as the thickness of the GFRP tube increases.

Application of acoustic emission monitoring for assessment of bond performance of corroded reinforced concrete beams

2016 ◽  
Vol 16 (6) ◽  
pp. 732-744 ◽  
Author(s):  
Ahmed A Abouhussien ◽  
Assem AA Hassan
Keyword(s):  
Acoustic Emission ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Signal Strength ◽  
Point Load ◽  
Reinforced Concrete Beams ◽  
Bond Failure ◽  
Acoustic Emission Monitoring ◽  
Bond Performance ◽  
Emission Monitoring

This article presents the results of an experimental investigation on the application of acoustic emission monitoring for the evaluation of bond behaviour of deteriorated reinforced concrete beams. Five reinforced concrete beam–anchorage specimens designed to undergo bond failure were exposed to corrosion at one of the anchorage zones by accelerated corrosion. Two additional beams without exposure to corrosion were included as reference specimens. The corroded beams were subjected to four variable periods of corrosion, leading to four levels of steel mass loss (5%, 10%, 20% and 30%). After these corrosion periods, all seven beams were tested to assess their bond performance using a four-point load setup. The beams were continuously monitored by attached acoustic emission sensors throughout the four-point load test until bond failure. The analysis of acquired acoustic emission signals from bond testing was performed to detect early stages of bond damage. Further analysis was executed on signal strength of acoustic emission signals, which used cumulative signal strength, historic index ( H( t)) and severity ( Sr) to characterize the bond degradation in all beams. This analysis allowed early identification of three stages of damage, namely, first crack, initial slip and anchorage cracking, before their visual observation, irrespective of corrosion level or sensor location. Higher corrosion levels yielded significant reduction in both bond strength and corresponding acoustic emission parameters. The results of acoustic emission parameters ( H( t) and Sr) enabled the development of a damage classification chart to identify different stages of bond deterioration.

Experimental Research on Interfacial Bond Performance in Rock Anchor with High-Performance Grouting Medium

2012 ◽  
Vol 517 ◽  
pp. 932-938 ◽  
Author(s):  
Zhi Fang ◽  
Hong Qiao Zhang
Keyword(s):  
Rock Mass ◽  
Bond Strength ◽  
High Performance ◽  
Interfacial Bond ◽  
Interfacial Bond Strength ◽  
Bond Performance ◽  
Pull Out ◽  
Steel Bar ◽  
Reactive Powder ◽  
Ground Anchor

There exist the problems such as low bond strength and bad durability in the ordinary grouting slurry of the ground anchor system at present. The high-performance grouting mediums RPC (Reactive Powder Concrete) and DSP (Densified Systems containing homogeneously arranged ultrafine Particles) would become the potential replacement of grouting medium in ground anchor resulting from their high compressive strength, durability and toughness. Based on a series of pull-out tests on ground anchors with different high-performance grouting medium of RPC and DSP , different bond length in the construction field, the bond performance on the interfaces between anchor bolt (deformed steel bar) and grouted medium as well as between grouted medium and rock mass was studied. The results indicate that the interfacial bond strength between RPC or DSP and deformed steel bolt ranges within 23-31Mpa, far greater than that (about 2-3MPa) between the ordinary cementitious grout and deformed steel bar. Even though the interfacial bond strength between the grouted medium and rock mass of limestone was not obtained in the test since the failure mode was pull-out of those steel bar rather than the interface shear failure between grouted medium and rock mass, the bond stress on the interface reached 6.2-8.38 MPa, also far greater than the bond strength (about 0.1-3MPa) between the ordinary cementitious slurry and rocks.

Experimental Study on Bond Behavior of GFRP-to-Cement Mortar

2011 ◽  
Vol 94-96 ◽  
pp. 543-546
Author(s):  
Ning Zhang ◽  
Ai Zhong Lu ◽  
Yun Qian Xu ◽  
Pan Cui
Keyword(s):  
Aluminium Alloy ◽  
Cement Mortar ◽  
Bond Stress ◽  
Reinforcing Bars ◽  
Bond Performance ◽  
Gfrp Bars ◽  
Pull Out ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Average Bond

Direct pull-out tests were performed to evaluate the bond performance of glass fiber-reinforced polymer (GFRP) reinforcing bars in cement mortar. Specimens with different bar diameters and different grouted lengths (i.e., 5d, 10d and 15d, d is the diameter of bars) are prepared for the pull-out tests. For comparison, specimens with plain aluminium alloy bars (AAB) were tested as well. The result shows that the average bond stress between plain aluminium alloy bars and cement is much smaller than that between the deformed GFRP bars and cement; thin GFRP bars tended to have larger average bond stress; the shorter the grouted length, the smaller the maximum average bond stress. Only part of grouted length undertakes the bond stress and the length depends on the shear modulus of GFRP and the surrounding material.

Bond performance of GFRP and deformed steel hybrid bar with sand coating to concrete

2016 ◽  
Vol 36 (6) ◽  
pp. 464-475 ◽  
Author(s):  
Minkwan Ju ◽  
Gitae Park ◽  
Sangyun Lee ◽  
Cheolwoo Park
Keyword(s):  
Glass Fiber ◽  
Modulus Of Elasticity ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced Polymer ◽  
Bond Performance ◽  
Polymer Hybrid ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Steel Bar

In this study, we experimentally investigated the bond performance of a glass fiber-reinforced polymer hybrid bar with a core section comprising a deformed steel bar and a sand coating. The glass fiber-reinforced polymer and deformed steel hybrid bar (glass fiber-reinforced polymer hybrid bar) can contribute to longer durability and better serviceability of reinforced concrete members because of the increased modulus of elasticity provided by the deformed steel bar. Uniaxial tensile tests in compliance with ASTM D 3916 showed that the modulus of elasticity of the glass fiber-reinforced polymer hybrid bar was enhanced up to three times. For the bond test, a total of 30 specimens with various sand-coating and surface design parameters such as the size of the sand particles (0.6 mm and 0.3 mm), sand-coating type (partially or completely), number of strands of fiber ribs (6 and 10), and pitch space (11.4 mm to 29.1 mm) of the fiber ribs were tested. The completely sand-coated glass fiber-reinforced polymer hybrid bar exhibited a higher bond strength (90.5%) than the deformed steel bar and a reasonable mode of failure in concrete splitting. A modification parameter to the Eligehausen, Popov, and Bertero (BPE) model is suggested based on the representative experimental tests. The bond stress–slip behavior suggested by the modified BPE model in this study was in reasonable agreement with the experimental results.

Utilizing alkali-activated materials as ordinary Portland cement replacement to study the bond performance of fiber-reinforced polymer bars in seawater sea-sand concrete

2022 ◽  
pp. 136943322110651
Author(s):  
Ruiming Cao ◽  
Bai Zhang ◽  
Luming Wang ◽  
Jianming Ding ◽  
Xianhua Chen
Keyword(s):  
Tensile Strength ◽  
Bond Strength ◽  
Ordinary Portland Cement ◽  
Concrete Strength ◽  
Fiber Reinforced Polymer ◽  
Bond Performance ◽  
Reinforced Polymer ◽  
Sea Sand ◽  
Frp Bars ◽  
Alkali Activated

Alkali-activated materials (AAMs) are considered an eco-friendly alternative to ordinary Portland cement (OPC) for mitigating greenhouse-gas emissions and enabling efficient waste recycling. In this paper, an innovative seawater sea-sand concrete (SWSSC), that is, seawater sea-sand alkali-activated concrete (SWSSAAC), was developed using AAMs instead of OPC to explore the application of marine resources and to improve the durability of conventional SWSSC structures. Then, three types of fiber-reinforced polymer (FRP) bars, that is, basalt-FRP, glass-FRP, and carbon-FRP bars, were selected to investigate their bond behavior with SWSSAAC at different alkaline dosages (3%, 4%, and 6% Na2O contents). The experimental results manifested that the utilization of the alkali-activated binders can increase the splitting tensile strength ( ft) of the concrete due to the denser microstructures of AAMs than OPC pastes. This improved characteristic was helpful in enhancing the bond performance of FRP bars, especially the slope of bond-slip curves in the ascending section (i.e., bond stiffness). Approximately three times enhancement in terms of the initial bond rigidity was achieved with SWSSAAC compared to SWSSC at the same concrete strength. Furthermore, compared with the BFRP and GFRP bars, the specimens reinforced with the CFRP bars experienced higher bond strength and bond rigidity due to their relatively high tensile strength and elastic modulus. Additionally, significant improvements in initial bond stiffness and bond strength were also observed as the alkaline contents (i.e., concrete strength) of the SWSSAAC were aggrandized, demonstrating the integration of the FRP bars and SWSSAAC is achievable, which contributes to an innovative channel for the development of SWSSC pavements or structures.

Quantifying In Situ Tack Coat Performance Using the TackBond Tester for Quality Control

2021 ◽  
pp. 036119812110581
Author(s):  
Blaine M. Wruck ◽  
Erdem Coleri ◽  
Richard Villarreal ◽  
Vikas Kumar ◽  
James Batti
Keyword(s):  
Control Process ◽  
Test System ◽  
Strong Correlations ◽  
Bond Quality ◽  
Test Device ◽  
Bond Performance ◽  
Direct Shear Tests ◽  
Construction Specifications ◽  
Tack Coat

In light of the various quality assurance (QA) issues pertaining to tack coats that occur during construction, there is a need for a means of verifying interlayer bond quality in situ. Despite the immense use of tack coat as a constituent in paving, there are no construction specifications with provisions for the quantification of tack coat bond quality in laboratory or field settings. In this study, a construction QA process for tack coat bond performance was proposed. A novel field tack coat bond strength test device, TackBond, was developed and used for this purpose. The performance of engineered (new tack coat technologies that are tracking less) and conventional tack coats was also evaluated in the laboratory and the field using the developed TackBond test system. The TackBond device was improved in this study by adding features that render it more practical, portable, accurate, and better suited for a variety of pavement surface conditions. Engineered tack coat performance was compared with that of tack coats used conventionally on both milled and overlay surface types. The suitability of the TackBond Test device for capturing the true response of each tack coat was first evaluated by comparing results from TackBond laboratory tests with monotonic direct shear tests (DST) on laboratory-produced samples. Strong correlations between the two test types were achieved. Results of field and laboratory TackBond tests showed that the in situ QA control process developed in this study could be effectively used to improve the in situ tack coat bond performance.

scholarly journals Effect of the degree of corrosion on bond performance of Cement Polymer Composite (CPC) Coated steel rebars

2018 ◽  
Vol 199 ◽  
pp. 04010
Author(s):  
Deepak K. Kamde ◽  
Radhakrishna G. Pillai
Keyword(s):  
Bond Strength ◽  
Polymer Composite ◽  
Continuous Monitoring ◽  
Coated Steel ◽  
Bond Performance ◽  
Pull Out ◽  
Curing Period ◽  
Uncoated Steel ◽  
Concrete Coating ◽  
Steel Rebars

Currently, large infrastructures (bridges, highways, etc.) are designed for more than 100 years. To achieve long service life, coated rebars (mostly, cement polymer composite (CPC) coated rebars) are being used to enhance the corrosion resistance. However, inadequately coated rebars can lead to premature corrosion. This can also affect the bond between the rebar and the concrete. To assess the effect of CPC coating on bond strength, pull-out specimens of (150×150×100) mm with 12 mm diameter rebar with 100 mm embedded length were cast and tested. For this, three replica specimens with two types of reinforcement namely, i) Uncoated steel ii) CPC coated steel were cast. To induce corrosion, additional five specimens with CPC coated steel rebars were cast with premixed chloride and cured for 28 days. During the curing period, continuous monitoring of corrosion potential and rate was done and degree of corrosion was assessed. The effect of degree of corrosion on bond of steel-concrete-coating interface was quantified. The CPC coated rebars without corrosion exhibited 10% bond reduction. CPC coated rebars with corrosion exhibited 30-70% reduction in bond strength. Also, the corrosion is found to adversely influence the stiffness of the bond.

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