Simulation of surface preparations to predict the bond behaviour between normal strength concrete and ultra-high performance concrete

Ganesh, P.; Murthy, A. Ramachandra

doi:10.1016/j.conbuildmat.2020.118871

Cited by 45 publications

(7 citation statements)

References 37 publications

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“…UHPC is a promising material for reinforced concrete structures because it has significant potential for creating new architectural perspectives as well as structural systems with a prolonged service life and low maintenance costs thanks to its superior durability performance [13]. Due to its hydraulic action, high strength activity, and fineness value [14], GGBS may be one of the best alternative cementitious materials for use in UHPC that will allow for a reduction in Portland cement dosage while maintaining satisfactory performance. It is anticipated that the use of UHPC in cast-in-situ applications will increase in the near future.…”

Section: Introductionmentioning

confidence: 99%

Hydration heat, strength and microstructure characteristics of UHPC containing blast furnace slag

Yalçınkaya

Çopuroğlu

2021

Journal of Building Engineering

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Ultra-high performance concrete (UHPC) is an innovative cement-based composite with high mechanical performance under tensile and compressive loads, extremely low permeability, and excellent durability. Because of these features, UHPC has the potential to contribute to the development of new architectural perspectives and structural systems with prolonged service life; therefore, it is anticipated that the use of UHPC in cast-in-situ applications will increase in the near future. As a result of its high Portland cement dosage, the hydration heat of UHPC can be relatively high compared to that of conventional concrete. Thus, ground granulated blast furnace slag (GGBS) can be used in UHPC formulation for reducing Portland cement dosage thereby limiting hydration heat while also addressing ecological and engineering concerns. In the scope of this study, the effects of GGBS replacement (0%, 30%, and 60%) on the hydration heat, strength, and microstructural characteristics of UHPC were studied. Results showed that GGBS-bearing UHPCs are more sensitive to ambient temperature in respect to cumulative heat. 60% GGBS replacement reduced cumulative heat release by 36% and 28% at 20 • C and 35 • C respectively. So, the benefit of GGBS on reducing hydration heat is less pronounced in hot weather. Performance differences in strength depending on the replacement ratio were only noticeable on the first day of curing. Prolonged curing time and fiber inclusion eliminated strength differences. Microstructural investigations indicated that Ca(OH) 2 can be lowered up to 0.5%, and the Ca/Si ratio of the C-S-H phase was reduced below the value of 1.0 after 90 days of curing as a result of GGBS replacement.

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Section: Introductionmentioning

confidence: 99%

Hydration heat, strength and microstructure characteristics of UHPC containing blast furnace slag

Yalçınkaya

Çopuroğlu

2021

Journal of Building Engineering

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“…3 Some authors (25,(27)(28)(29)found the split bond strength with different sizes of gravel, surface patterns and different overlay materials. With the use of the gravel patterns, the bond strength was increased by 60.3% as compared to the chipped surface (30). Bond strength testing of split prism specimens was performed using a modified version of ASTM C496, with results of 1.5 MPa for the 0.05 mm texture and the bond strength was nearly 3.7 MPa for the rough texture (31).…”

Section: Splitting Prism Testmentioning

confidence: 99%

“…From the failure mode, it is clear that mortar thickness influenced the failure behavior. Ganesh et al(30) expected the bond behavior with model analysis and found that the maximum difference in the experimental bond strength and model bond strength was nearly 12%. It is critical to understand that the result of a specimen that did not fail at the bonding interface (for example, a pull-off test that failed in the substrate concrete) will show interface bond stress at specimen failure, not interface bond strength(59).Rather than the layer failure the full failure is subdivided into adhesive failure and cohesive failure based on the loading process.…”

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confidence: 99%

Effect of various interface bond tests and their failure behavior on substrate and overlay concrete -A Review

Pulkit¹,

Saini²,

Chalak³

2023

Res. Eng. Struct. Mater.

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Concrete is a widely used building material in the construction sector. Still, the lifespan of concrete is limited because many factors can influence the performance of concrete structures, which can be classified based on physical, chemical, and mechanical changes that occur during their service life. In addition, the structure's lifespan is being reduced due to adverse environmental conditions and loads. These require maintenance, restoration, or reconstruction. Therefore, considerable concrete remediation is necessary, and the best option is to repair it. However, the cost associated with restoring the deteriorating concrete structures is higher. The repaired concrete strength mainly depends on the interface layer, situated between the substrate (old) and overlay (new) concrete. The interface layer strength primarily depends on interface adhesion, friction, aggregate interlock, bonding agent, compaction, cleanliness, moisture content, concrete age, roughness, and time-dependent variables. Multiple tests are available to analyse the bonding behavior between substrate-overlay concrete. However, no particular method is available to access the bond strength. This paper describes various methods and techniques used by researchers to evaluate bond strength. The reviewed summary has shown that concrete repair is the best solution, and higher-strength concrete uses show better shear results; also, conventional concrete is more economical than higher-strength concrete. Among all the available tests the bi-surface shear test and slant shear test are the more suitable method to determine the bond strength.

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“…Te 28day interface shear strength of precast NC-postcast UHPC was 13.63 MPa, 70% higher than the untreated result. Carbonell Munoz et al [23], Long et al [24], and Ganesh and Ramachandra Murthy [25] used the same test method with the same grooved form and derived the 28-day shear strengths of the UHPC-NC interface as 17.5 MPa, 20 MPa, and 13.3 MPa. Te above investigations show that grooving is benefcial to improving the interface shear capacity, but the improvement is limited and some of the experimental results cannot yet reach the requirement of 14 MPa (interface shear strength) specifed by the American Concrete Institute.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation on Shear Strength between Ultra-High-Performance Concrete and Normal Concrete Substrates

Jiang

Song

et al. 2023

Advances in Materials Science and Engineering

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Tunnel engineering in China has developed to the stage of both construction and maintenance, and the problem of structural defect is widespread. The cast-in-situ jacketed arch treatment takes a long time and has a great impact on traffic. It is urgent to develop prefabricated treatment technology, and the guarantee of mechanical properties of the prefabricated UHPC-post-cast NC interface is the key problem. Through the oblique shear test, combined with the XTDIC full-field strain monitoring system, the failure process and failure mode of UHPC-NC specimens were studied and analyzed under different interface keyway numbers (0, 1, 2, and 3), interface agents (meshless interface agent, cement slurry, silica fume modified cement slurry, modified cement slurry mesh, cement slurry, and expansion agent), and NC pouring grades (C30, C35, C40, and C50), as well as the influencing factors of shear strength, shear stiffness, and the slip model of the bonding interface. The results show that there are four typical failure modes in UHPC-NC under compression and shear, including complete interface failure (Class A), interface failure + NC shear failure (Class B), NC compression failure (Class C), and interface failure + NC compression failure + NC slip failure in the keyway (Class D). The complete interface failure type (Type A) without keyway treatment has sudden failure, and the keyway has the ability to disperse load and limit interface slip. The principal strain decreases along the normal sides of the interface, and the influence range of UHPC and NC sides is about 16.2 mm and 17.5 mm, respectively. In practice, the thinnest part of the treatment structure should not be less than 2 cm. The shear strength of the prefabricated UHPC-post-pouring NC interface is generally low, and the maximum shear strength of 13.9 MPa obtained by the test is still lower than the recommended value of 14–21 MPa of ACI 546.3R-14. In treatment design, the interface shear reinforcement can be introduced to ensure the cooperative bearing capacity. The shear strength of the prefabricated UHPC-post-poured NC interface is slightly affected by the interface agent and postpoured concrete grade and increases linearly with the increase in the number of keyways. When the number of keyways is equivalent to the roughness index, the relationship between the shear strength and the roughness is as follows: f s = 1.664 + 3.030 R z . Under the action of keyway, the interface slip of UHPC-NC can be simplified into four stages: the interface slip stage, the keyway strengthening stage, the shear yield stage, and the specimen failure stage. Based on this, a prefabricated UHPC-post-pouring NC interface slip model was proposed, and the experimental results of key parameters such as interface bond strength, stiffness, and slip amount at different stages were obtained by fitting. In the keyway strengthening stage, the shear stiffness increases linearly first and then tends to be stable with the increase in the number of keyways. The maximum shear stiffness is about 20 MPa/mm, and the maximum interfacial slip increases with the increase in the number of keyways, which improves the overall shear resistance. The results can be used in the design of a tunnel-fabricated treatment segment.

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Simulation of surface preparations to predict the bond behaviour between normal strength concrete and ultra-high performance concrete

Cited by 45 publications

References 37 publications

Hydration heat, strength and microstructure characteristics of UHPC containing blast furnace slag

Hydration heat, strength and microstructure characteristics of UHPC containing blast furnace slag

Effect of various interface bond tests and their failure behavior on substrate and overlay concrete -A Review

Experimental Investigation on Shear Strength between Ultra-High-Performance Concrete and Normal Concrete Substrates

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