Crack development in transverse loaded base-restrained reinforced concrete walls

Micallef, Marianna; Vollum, Robert L.; Izzuddin, B.A.

doi:10.1016/j.engstruct.2017.04.035

Cited by 14 publications

(7 citation statements)

References 7 publications

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“…To this end, four RC walls (C-W5 to C-W8) with combined edge and end restraint were cast in the Structures Laboratory at Imperial College London. The results of four walls tested with edge restraint are reported elsewhere (Micallef, 2015). Over the entire test period of two years, the average air temperature varied between 20 °C and 27 °C.…”

Section: Methodsmentioning

confidence: 99%

Cracking in walls with combined base and end restraint

Micallef

Vollum

Izzuddin

2017

Magazine of Concrete Research

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Restraint of early-age thermal and long-term shrinkage strain can cause cracking in reinforced concrete members. Eurocode 2 provides guidance on the design of crack control reinforcement in reinforced concrete elements with base (edge) and end restraint but not combined base and end restraint which commonly occurs. The paper describes an experimental programme, which was conducted to investigate early-age and long-term shrinkage cracking in reinforced concrete walls with combined base and end restraint. The main variables in the test programme were concrete cover and reinforcement ratio. Early-age cracking is simulated with nonlinear finite element analysis, which is shown to capture the observed behaviour adequately. Eurocode 2 gives reasonable estimates of long-term crack widths in the tested walls if edge restraint is assumed but significantly overestimates crack widths if the worst case of end restraint is assumed.

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Section: Methodsmentioning

confidence: 99%

Cracking in walls with combined base and end restraint

Micallef

Vollum

Izzuddin

2017

Magazine of Concrete Research

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“…The current EN 1992‐3 6 does not provide any methods for determination of the imposed strains but gives recommendations on the degree of external restraint for different restraint configurations. However, since it is known that the first crack initiates in the central part of the base‐restrained element and this crack usually has the greatest width, 34 it seems reasonable to the authors in determination of the cracking strain to assume the highest recommended value of the restraint factor at the base, which according to EN 1992‐3 is equal to 0.5. Provisions of EN 1992‐3 were elaborated in CIRIA C660 21 and later in CIRIA C766 7 .…”

Section: Edge‐restrained Elementsmentioning

confidence: 99%

Standardized models for cracking due to restraint of imposed strains—The state of the art

Jędrzejewska

Zych

Kanavaris

et al. 2023

Structural Concrete

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Crack control throughout the service life of a structure has always been a challenging task for engineers and asset owners, particularly those who are involved with the design and construction of structures with increased durability requirements, such as liquid retaining structures, nuclear containment buildings or structures in direct contact with ground, but also other externally restrained structures. For these reasons, several standardized methods exist throughout the global engineering community which encompass differences between them. This work is a state‐of‐the‐art review of the methods for crack width control due to imposed strains recommended by different regulatory documents from Europe, USA, Australia and Japan, and provide a reasonable degree of guidance with respect to the assumptions, possibilities and restrictions of each method. This work resonates with the scope of the RILEM TC 287‐CCS: Early age and long‐term crack width analysis in RC structures.

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“…Although informative the tests of Stoffers and Kheder et al are unrepresentative of practical construction due to the use of micro‐concretes and small diameter reinforcement. More recently, Micallef 5 tested a series of edge restrained walls cast onto a kicker connected to a steel beam with shear studs. A drawback with this test arrangement is that substituting the concrete base with a steel beam affects the thermal flow between restrained and restraining elements at the joint level.…”

Section: Introductionmentioning

confidence: 99%

Assessment of cracking performance in edge restrained RC walls

Elwakeel

Shehzad

Khoury

et al. 2022

Structural Concrete

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Excessive cracking due to restraint of thermal and shrinkage strains is a widespread problem in the concrete construction industry. In design, restraint induced cracking is managed by the provision of reinforcement intended to distribute internal strains in such a way as to control the cracking pattern and limit crack widths. The area of secondary (horizontal) reinforcement required in members such as retaining walls and water tanks is often governed by the need to control early age thermal cracking. This paper presents results from four edge restrained walls tested at Imperial College London and the University of Leeds as part of an Engineering and Physical Sciences Research Council funded project into restraint induced cracking. The paper describes the development of volumetric strain and cracking in the tested walls. The cracking performance is assessed by comparing the restrained strain with the tensile strain capacity of concrete.degree of restraint, early age, edge restraint, imposed strain, thermal strain 1 | BACKGROUND | IntroductionConcrete structures undergo early age as well as longterm (LT) volumetric changes due to several actions including early-age thermal (EAT) strains and LT shrinkage strains. 1 If these strains are restrained either internally (by reinforcement or another part of the same cross section) or externally by adjoining members, stresses develop in the concrete with a magnitude proportional to the restrained strain. This phenomenon can lead to cracking if the stress levels exceed the tensile strength of the concrete. 2 Little experimental work has been carried out to investigate cracking in edge restrained members which are the subject of this paper. Stoffers 3 examined the influence of reinforcement ratio, wall aspect ratio and presence or absence of wall curvature in 18 tests of reduced scale micro-concrete walls with cross section of 60 Â 375 mm 2 . The maximum reinforcement diameter was 3 mm. Kheder et al. 4 examined the influence of wall aspect ratio. They tested 14 reduced-scale mortar walls Discussion on this paper must be submitted within two months of the print publication. The discussion will then be published in print, along with the authors' closure, if any, approximately nine months after the print publication.

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Crack development in transverse loaded base-restrained reinforced concrete walls

Cited by 14 publications

References 7 publications

Cracking in walls with combined base and end restraint

Cracking in walls with combined base and end restraint

Standardized models for cracking due to restraint of imposed strains—The state of the art

Assessment of cracking performance in edge restrained RC walls

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