Cohesive‐frictional model for bond and splitting action of prestressing wire

Abstract. The goal of the article is to elaboration analytical models describing a new system of reinforcing three-layer walls of large-panel buildings with bonded anchors. The use of this type of fasteners that bond the façade texture layer to the structural slab is necessary due to the low durability of previously used suspension elements. Various bonded anchorage systems were considered. The new anchorage systems were designed as two-anchors systems (horizontal anchor and diagonal anchors) and three-anchors systems (horizontal anchor and two diagonal anchors). The inclinations of these anchors are in the range of 30˚-60˚ in relation to the surface of the element. For the above types of reinforcements, analytical models have been developed that take into account the change of strength parameters of the resin and steel from which the anchors were made, the interaction of materials resin-steel and resin-concrete and the effect of the simultaneous action of pull-out and shearing forces. Moreover, was assumed the simultaneous destruction of fasteners two-and three-anchors. The elaborated analytical models will be used to determine the load-bearing capacity of the new connector system, which will allow the elaboration of guidelines for strengthening three-layer walls of largepanel slab buildings.

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“…The research of capacity on pull-out carry out among other [6][7][8][9][10][11][12][13]. This is done in two stages.…”

Section: Methods For Determining the Capacity Of Bonded Anchor Pulloumentioning

confidence: 99%

Analytical modelling of a three-layer wall system of strengthening for large-panel slab buildings by means of bonded anchors

2018

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“…Lundgren [21] advocated that the bond behaviour should not be inserted into the model as a fixed input but that it should result rather from an analysis. Galvez et al [7,22] simulated the bond behaviour by implementing a non-associative yield function representing the relation between the bond strength and the compressive stress at the steel-concrete interface. The confinement of the surrounding concrete was taken into account in the model using a cohesive crack model.…”

Section: Introductionmentioning

confidence: 99%

“…Mechanical resistance of the strand itself is of great importance when ribbed or indented bars are concerned [9,11,24]. The mechanical resistance can be converted into an equivalent frictional behaviour which depends on the characteristics of the tendon and of the surrounding concrete [22,24]. Two major phenomena can be denoted concerning the mechanical resistance, the pitch effect (figure 2a) and the 'lack-of-fit' effect (figure 2b).…”

Section: Introductionmentioning

confidence: 99%

A two-stage modelling approach for the analysis of the stress distribution in anchorage zones of pre-tensioned, concrete elements

Steensels

Vandoren

Degée

2017

Engineering Structures

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An innovative strategy for the analysis and design of the anchorage zones of pre-tensioned, concrete girders is presented. In this approach, the bond behaviour of the prestress strands is first characterised in a small-sized beam model. A new relation between the slip and radial strain of the prestress strand is introduced and used together with the radial stress-strain relation resulting from a thick-walled cylinder model to establish the bond-slip behaviour at the steel-concrete interface. This bond behaviour is implemented in a numerical model and validated via a comparison of the computed transfer length with the results of two experimental campaigns. Next, the bond-slip relation of the small-scale model is applied in full-scale models of pre-tensioned, concrete girders to derive the stress distribution in the anchorage zones. The non-linear material behaviour of concrete is taken into account and a comparison of the numerical results with full-scale experimental data is made. An acceptable agreement is achieved between the experimental results and the numerical calculations regarding the bond behaviour and transfer lengths as well as the crack patterns and the stress values in the reinforcement bars. This efficient modelling approach allows for a full analysis of the anchorage zone based solely on the geometrical and material properties known at the design stage.

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“…When indented wires or strands are used, the interlock mechanism plays a significant role in the bond capacity as has been shown elsewhere . The increasing of the roughness of the steel surface, or even the increasing of the concrete strength, is beneficial for bond, though they may be harmful because the risk of splitting increases, which is dangerous for dropping the confinement and diminishing the bond . Hoyer's effect, present at the end of the prestressed concrete element, emphasises such behaviour .…”

Section: Introductionmentioning

confidence: 99%

“…In this landscape, bond between prestressed steel and concrete remains a complex problem depending on many parameters, as the FIB Report shows. The main mechanisms involved in the bond modelling of the prestressed concrete are the following : Steel to concrete interface behaviour, especially geometry and depth of the indentations of the wire/strand, and strength of the surrounding concrete.Splitting action of the wire/strand. This effect is induced by the Poisson's effect when releasing the wire/strand prestressed stress and by the interlocking mechanism of the indentation.…”

Section: Introductionmentioning

confidence: 99%

Study of bond stress–slip relationship and radial dilation in prestressed concrete

Benítez

Gálvez

Casati

2012

Num Anal Meth Geomechanics

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This paper presents two test procedures for evaluating the bond stress-slip and the slip-radial dilation relationships when the prestressing force is transmitted by releasing the steel (wire or strand) in precast prestressed elements. The bond stress-slip relationship is obtained with short length specimens, to guarantee uniform bond stress, for three depths of the wire indentation (shallow, medium and deep). An analytical model for bond stress-slip relationship is proposed and compared with the experimental results. The model is also compared with the experimental results of other researchers. Since numerical models for studying bond-splitting problems in prestressed concrete require experimental data about dilatancy angle (radial dilation), a test procedure is proposed to evaluate these parameters. The obtained values of the radial dilation are compared with the prior estimated by numerical modelling and good agreement is reached.

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Cohesive‐frictional model for bond and splitting action of prestressing wire

Cited by 4 publications

References 12 publications

Analytical modelling of a three-layer wall system of strengthening for large-panel slab buildings by means of bonded anchors

Analytical modelling of a three-layer wall system of strengthening for large-panel slab buildings by means of bonded anchors

A two-stage modelling approach for the analysis of the stress distribution in anchorage zones of pre-tensioned, concrete elements

Study of bond stress–slip relationship and radial dilation in prestressed concrete

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