Bond fatigue of epoxy coated reinforcing bars

Johnston, David W.; Zia, Paul

doi:10.1007/bf02474052

Cited by 13 publications

(19 citation statements)

References 3 publications

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“…The slab specimens showed little difference in spacing, crack width, deflection, or ultimate strength (Johnston and Zia 1982). R.A. Treece and J.O.…”

Section: Epoxy Coatingmentioning

confidence: 91%

Investigation of Bridge Deck Cracking in Various Bridge Superstructure Systems

Frosch¹,

Blackman²,

Radabaugh³

2003

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Prepared in cooperation with the Indiana Department of Transportation and Federal Highway Administration. AbstractMany bridges in the state of Indiana have been identified to have cracking in the concrete deck. Cracking has been identified in the negative and positive moment regions of bridges on both the top and bottom surfaces and can appear before or shortly after the opening of the structure to live loads. Significant crack widths and various degrees of cracking exist in different bridge systems including both concrete and steel superstructures. This research project was divided into five phases to determine the factors affecting transverse and longitudinal bridge deck cracking, as well as, to develop design recommendations that minimize or prevent these types of bridge deck cracking. The research focused on the design and construction of new bridge decks. However, an overview of overlay cracking is also presented. The first phase was a field evaluation to investigate the scope of the problem. Using the information gathered from the first phase, the second phase instrumented a typical bridge structure to provide an understanding of the behavior of transverse cracks in a concrete bridge deck. With the findings from the previous two phases, the third phase conducted a laboratory investigation to study the effects of shrinkage and restraint of a concrete deck and to determine the contribution of stay-in-place steel forms to the formation of transverse cracking. The fourth phase evaluated the effect of formwork type on restrained shrinkage. In the final phase, the effect of reinforcing bar spacings and epoxy thickness on crack width and spacings were evaluated. Based on the research investigation, transverse deck cracking is caused by restrained shrinkage of the concrete deck while longitudinal cracking is caused by a combination of factors including restrained shrinkage and a construction detail that turns the leg of an angle used to support stay-in-place formwork into the deck. Design and construction recommendations are provided to minimize transverse, longitudinal, and overlay map cracking. 17.

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“…The slab specimens showed little difference in spacing, crack width, deflection, or ultimate strength (Johnston and Zia 1982). R.A. Treece and J.O.…”

Section: Epoxy Coatingmentioning

confidence: 91%

Investigation of Bridge Deck Cracking in Various Bridge Superstructure Systems

Frosch¹,

Blackman²,

Radabaugh³

2003

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“…It was stated that overall, repeated loading appears to increase the bond ratio by increasing the failure load of beams with epoxy-coated reinforcement more than for uncoated reinforcement, A slight increase in bond ratio due to application of repeated loads was also reported by Johnston [2].…”

Section: Effect Of Repeated Loadingmentioning

confidence: 73%

“…Another consideration has been the structural performance, i.e., deflection and cracking of members reinforced with this type of steel. Research in the past 20 years has shown that epoxy-coating results in a wide range of bond strength reduction [1][2][3][4][5][6][7][8]. The greatest bond reduction occurred in splitting type failure mode [3].…”

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confidence: 99%

Behavior of Concrete Bridge Decks and Slabs Reinforced with Epoxy Coated Steel

Hasan¹,

Ramírez²

1995

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Thirty-four slab specimens with splices and transverse steel were tested in the laboratory to evaluate the structural performance of concrete bridge decks reinforced with epoxy-coated steel. Thirty specimens were tested under fatigue loading, and four were tested monotonically. Evaluations were made by comparing the performance of uncoated bar concrete specimens with that of epoxy-coated specimens under service and ultimate load conditions. In addition, a field evaluation of six bridges was conducted to assess the in-service condition of concrete bridge decks reinforced with epoxy-coated steel in Indiana.The laboratory results indicated fewer but wider cracks in specimens with epoxy-coated reinforcement No significant differences in the first cracking load were found between uncoated specimens and epoxy-coated specimens. The splitting crack load and failure load were lower for specimens with epoxy-coated steel. Deflections of epoxy-coated specimens were larger. The differences in crack width and deflection were reduced with repeated loading. The average bond ratios were 0.78 and 0.75 for repeated loading tests.No signs of corrosion were found in the epoxy-coated steel samples extracted from cores taken in the six bridges evaluated. Evaluation of the field data revealed that the combination of adequate concrete cover and epoxy-coated steel has provided a good corrosion protection to date. This evaluation included the first bridge in Indiana where epoxy-coated reinforcement was placed (Circa 1976

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“…The coefficients c in Eq. (39) have been calculated for the one-and two-triplon case on a computer in a similar fashion as the coefficients t for the effective Hamiltonian. The implementation of O eff acting on the ground state |0 follows the same line as described in detail for H eff in Ref.…”

Section: B Observables In the Spin Laddermentioning

confidence: 99%

“…In the broad field of spin liquid systems there has been an ongoing theoretical interest in the spin ladder and its extended versions [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]11,38]. The model is realized in a number of substances [39] and there is a large amount of experimental data available, see e.g. Refs.…”

mentioning

confidence: 99%

High order perturbation theory for spectral densities of multi-particle excitations: $\mathsf{S = \frac{1}{2}}$ two-leg Heisenberg ladder

Knetter

Schmidt

Uhrig

2003

The European Physical Journal B - Condensed Matter

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We present a high order perturbation approach to quantitatively calculate spectral densities in three distinct steps starting from the model Hamiltonian and the observables of interest. The approach is based on the perturbative continuous unitary transformation introduced previously. It is conceived to work particularly well in models allowing a clear identification of the elementary excitations above the ground state. These are then viewed as quasi-particles above the vacuum. The article focuses on the technical aspects and includes a discussion of series extrapolation schemes. The strength of the method is demonstrated for S = 1/2 two-leg Heisenberg ladders, for which results are presented.

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Bond fatigue of epoxy coated reinforcing bars

Cited by 13 publications

References 3 publications

Investigation of Bridge Deck Cracking in Various Bridge Superstructure Systems

Investigation of Bridge Deck Cracking in Various Bridge Superstructure Systems

Behavior of Concrete Bridge Decks and Slabs Reinforced with Epoxy Coated Steel

High order perturbation theory for spectral densities of multi-particle excitations: $\mathsf{S = \frac{1}{2}}$ two-leg Heisenberg ladder

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