Prediction of the bond strength of FRP-to-concrete under direct tension by ACO-based ANFIS approach

Analytical Investigation on the Effect of Test Setup on Bond Strength

CivilEng ◽

10.3390/civileng2010002 ◽

2021 ◽

Vol 2 (1) ◽

pp. 14-34

Author(s):

Konstantinos Tsiotsias ◽

Stavroula J. Pantazopoulou

Keyword(s):

Bond Strength ◽

Pullout Test ◽

Analytical Investigation ◽

Strength Increase ◽

Confining Stress ◽

Direct Tension ◽

Bond Slip ◽

Test Setup ◽

Long Time

Experimental procedures used for the study of reinforcement to concrete bond have been hampered for a long time by inconsistencies and large differences in the obtained behavior, such as bond strength and mode of failure, depending on the specimen form and setup used in the test. Bond is controlled by the mechanics of the interface between reinforcement and concrete, and is sensitive to the influences of extraneous factors, several of which underlie, but are not accounted for, in conventional pullout test setups. To understand and illustrate the importance of specimen form and testing arrangement, a series of computational simulations are used in the present work on eight distinct variants of conventional bar pullout test setups that are used routinely in experimental literature for the characterization of bond-slip laws. The resulting bond strength increase generated by unaccounted confining stress fields that arise around the bar because of the boundary conditions of the test setup is used to classify the tests with respect to their relevance with the intended use of the results. Of the pullout setups examined, the direct tension pullout test produced the most conservative bond strength results, completely eliminating the contributions from eccentricity and passive confinement.

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Assessment of Adhesion between RPC Overlay and Existing Concrete Substrate

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.802.95 ◽

2015 ◽

Vol 802 ◽

pp. 95-100

Author(s):

Bassam A. Tayeh ◽

B.H. Abu Bakar ◽

Megat Azmi Megat Johari

Keyword(s):

Bond Strength ◽

Experimental Program ◽

Early Age ◽

Structural System ◽

Direct Tension ◽

Conventional Concrete ◽

Existing Structures ◽

The Past ◽

Joint Surfaces ◽

Reactive Powder

The number of existing structures under repair and rehabilitation has extensively increased over the past two decades; these structures typically require performance enhancements including durable and safe repair and strengthening. The experimental program aimed to investigate the bond strength at the joint surfaces between conventional concrete substrate as existing concrete and reactive powder concrete RPC as new overlay concrete. Pull off test was used to quantify the direct tension of the bond strength. Different surfaces roughness were used for existing concrete. The obtained results, clearly showed that, RPC could be linked excellent to the existing concrete at early age; as a result, all failures occurred through the existing concrete, regardless of the surface roughness of existing concrete. RPC could be used as an excellent overlay concrete for increasing the durability at joint surfaces of the strengthened structural system.

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