Membrane action in reinforced concrete slabs

1990 ◽  
Vol 17 (5) ◽  
pp. 686-697 ◽  
Author(s):  
F. J. Vecchio ◽  
K. Tang
Keyword(s):  
Reinforced Concrete ◽  
Large Scale ◽  
Load Capacity ◽  
Experimental Program ◽  
Concrete Slabs ◽  
Order Effects ◽  
Membrane Action ◽  
Deformation Response ◽  
Reinforced Concrete Slabs ◽  
Compressive Membrane Action

The formation and influence of compressive membrane action in reinforced concrete slabs is discussed. An experimental program is described, in which two large-scale slab specimens were tested under concentrated midspan loads. One slab was restrained against lateral expansion at the ends, while the other was free to elongate. The laterally restrained specimen developed high axial compressive forces, which resulted in a significant increase in flexural stiffness and load capacity. A nonlinear analysis procedure was used to model specimen behaviour. The analysis method was found to adequately represent important second-order effects, and thus gave reasonably accurate predictions of load–deformation response and ultimate load. Key words: analysis, concrete, deformation, load, membrane, reinforced, slabs, strength, tests.

Load Redistribution Using Compressive Membrane Action in Reinforced Concrete Buildings

2011 ◽  
Vol 82 ◽  
pp. 272-277 ◽  
Author(s):  
Ben M. Punton ◽  
Mike P. Byfield ◽  
Peter P. Smith
Keyword(s):  
Reinforced Concrete ◽  
Experimental Testing ◽  
Load Capacity ◽  
Experimental Program ◽  
Membrane Action ◽  
Codes Of Practice ◽  
Load Paths ◽  
Arching Action ◽  
Compressive Membrane Action ◽  
Significant Underestimation

The primary function of any designed structure is to be able to support pre-determined static loads which allow the building to be occupied for its intended use. In the design process the unlikely event that the building is damaged must be considered. Often the focus is directed to the loss of primary loading elements that are fundamental to the integrity of the structure. The damage that is caused as a consequence may propagate causing collapse of surrounding elements culminating with the loss of an extensive proportion of the floor area. To prevent collapse inherent alternative load paths can be utilised. Both the elastic and plastic approved methods for the design of reinforced concrete in modern codes of practice neglect the effect of membrane forces. It has been recognised for some time that the omission of compressive membrane action (CMA), also described as ‘arching action’, can lead to a significant underestimation of load capacity. Previous studies which have attempted to determine if CMA is capable of supporting damaged columns under accidental loading conditions have not had supporting experimental testing of slabs at appropriate span to depth ratios. This paper presents an experimental program conducted on laterally restrained slab strips at approximately half scale. Combined with an analytical study, the extent to which CMA can be used as an effective robustness tool has been assessed.

scholarly journals Enhancing the Behavior of One-Way Reinforced Concrete Slabs by Using Laced Reinforcement

2019 ◽  
Vol 5 (3) ◽  
pp. 718
Author(s):  
Ali Faiq Hallawi ◽  
Ali Hussein Ali Al-Ahmed
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Load Capacity ◽  
Experimental Program ◽  
Concrete Slabs ◽  
Ultimate Load Capacity ◽  
Steel Ratio ◽  
Reinforced Concrete Slabs ◽  
Line Loads ◽  
Monotonic Load

This paper studies experimentally the behavior of laced reinforced concrete one-way slabs under monotonic load. The experimental program included testing three simply supported one-way slabs of dimensions (1500 mm length, 600 mm width, and thickness 130mm. One of these slabs was the control specimen which was designed without lacing reinforcement steel and the other two specimens designed were with two variable lacing reinforcement ratio (0.27% and 0.52%). All specimens were cast with normal of 22 MPa compressive strength. Specimens were tested under two equal line loads applied at the third parts of the slab (monotonic load) gradually applying up to failure. The specimens showed an enhanced in ultimate load capacity up to 40% as a result of increasing the lacing steel ratio to 0.52 %. Also, decreasing in deflection at service and at ultimate load levels by 42% and %57 respectively. In addition, the results showed that specimen with lacing reinforcement are more ductility than specimen without lacing reinforcement so using of lacing steel reinforcement leads to significant improvements in ductility index which reached to about 49% with increasing the lacing steel ratio to (0.52%).

On the nonlinear behaviour of reinforced concrete frames

1990 ◽  
Vol 17 (5) ◽  
pp. 698-704 ◽  
Author(s):  
F. J. Vecchio ◽  
S. Balopoulou
Keyword(s):  
Reinforced Concrete ◽  
Large Scale ◽  
Load Capacity ◽  
Concrete Strength ◽  
Theoretical Modelling ◽  
Nonlinear Behaviour ◽  
Concrete Frames ◽  
Membrane Action ◽  
Ultimate Load Capacity ◽  
Plane Frame

An experimental investigation is described in which a large-scale reinforced concrete plane frame is tested to study factors contributing to its nonlinear behaviour under short-term loading conditions. The test results indicate that frame behaviour can be significantly affected by second-order influences such as material nonlinearities, geometric nonlinearities, concrete shrinkage, tension stiffening effects, shear deformations, and membrane action. A nonlinear frame analysis procedure, previously developed taking these mechanisms into account, is shown to accurately predict most aspects of behaviour, including deflection response, ultimate load capacity, and failure mechansim. Aspects of the theoretical modelling which are in need of further improvement are also identified. Key words: analysis, behaviour, deformation, frame, large scale, nonlinear, reinforced concrete, strength, test.

scholarly journals Experimental Study of the Effect of Cavities on the Load Capacity of Two-Way Reinforced Concrete Plates on Fixed Concrete Thickness

2021 ◽  
Vol 921 (1) ◽  
pp. 012085
Author(s):  
W M T Atmadja ◽  
H Parung ◽  
R Irmawaty ◽  
A.A Amiruddin
Keyword(s):  
Reinforced Concrete ◽  
Load Capacity ◽  
Maximum Load ◽  
Initial Crack ◽  
Concrete Slabs ◽  
Loading Pattern ◽  
Reinforced Concrete Slabs ◽  
Solid Plate ◽  
Cast Concrete ◽  
Concrete Materials

Abstract The study aims to determine the effect of cavities on the load capacity of reinforced concrete slabs when compared to massive reinforced concrete slabs that have the same thickness, with the hope of reducing the structure’s weight and the use of concrete materials. The modified PVC pipes, as cavity formers, will be placed in the tensile area without reducing the flexural strength that is caused by the weak nature of concrete against tensile strength. The test is carried out on a full scale against 14 cm thick solid plates (PP-1), and hollow plates, which use modified PVC pipes (PB-2), with a cavity diameter of 7.6 cm that has the same thickness. The test uses joint supports on all four sides and the loading pattern is evenly distributed. All slabs are made, on the spot, of cast concrete with the same size and distance between the reinforcement. PVC hollow plate (PB-2) has the same effective thickness as solid plate but has 14% less concrete volume. The maximum load capacity on the solid plate (PP-1) is 522.66 kN and on the hollow plate (PB-2) is 444.33 kN. The melting capacity on the solid plate (PP-1) is 373,515 kN and on the hollow plate (PB-2) is 325,935 kN. Initial crack load capacity on the solid plate (PP-1) is 19.5 kN and on the hollow plate (PB-2) is 16.75 kN

scholarly journals Analysis of Fiber-Reinforced Concrete Slabs under Centric and Eccentric Load

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7152
Author(s):  
Zuzana Marcalikova ◽  
Vlastimil Bilek ◽  
Oldrich Sucharda ◽  
Radim Cajka
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Fiber Reinforced Concrete ◽  
Experimental Program ◽  
Concrete Slabs ◽  
Detailed Knowledge ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slabs ◽  
3D Deformation

Research on the interaction between slabs and subsoil involves the field of materials engineering, concrete structures, and geotechnics. In the vast majority of cases, research focuses on only one of these areas, whereas for advanced study and computer simulations, detailed knowledge of the whole task is required. Among the new knowledge and information upon which this article focuses is the evaluation of subsoil stress using specialized pressure cells, along with detailed measurements of the deformation of a fiber-reinforced concrete slab. From a design point of view, this research is focused on the issue of the center of the cross section and the influence of eccentricity. Knowledge in this area is not yet comprehensively available for fiber-reinforced concrete slabs, where 2D deformation sections of the slab and 3D deformation surfaces of the slab are used in experiments. The experimental program includes a centrically and eccentrically loaded slab. These are structural elements that were tested on a specialized device. Both slabs had the same concrete recipe, with a dispersed reinforcement content of 25 kg/m3. The dimensions of the slab were 2000 × 2000 × 150 mm. Laboratory tests assessed compressive strength, the modulus of elasticity, splitting tensile strength, and bending tensile strength. Based on approximate data from the 3D deformation surfaces, an evaluation of the load-displacement diagrams for the center of the slab and for the center of eccentricity was performed. In conclusion, an overall evaluation and discussion of the results relies on experiments and the mechanical properties of fiber-reinforced concrete.

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