Punching Shear Strengthening at the New Station Square in Berne, Switzerland

Author(s):  
Dominic Joray ◽  
Martin Diggelmann

<p>The reinforced concrete slab of the reconstructed Station Square in Berne needed to be strengthened against punching shear. The case study led to the application of a newly developed post-installed punching shear reinforcement with inclined bonded bars.</p>

2000 ◽  
Vol 27 (2) ◽  
pp. 338-348 ◽  
Author(s):  
Ehab F El-Salakawy ◽  
Maria Anna Polak ◽  
Monir H Soliman

The paper reports the results of an experimental investigation on the influence of shear studs on the behaviour of reinforced concrete slab-column edge connections with openings. The test parameters were the location of openings around the column, the size of openings, and the existence of shear reinforcement. The objective of the paper is to present and discuss the results of large-scale tests on slabs with shear stud reinforcement and compare these test results with those of tests on identical slabs but without shear reinforcement. All tested slabs contained same amounts of typical flexural reinforcement (ACI 318-95 and CSA A23.3-94). The presented test results can be used for studying the behaviour of slab-column connections and for calibration of the predictive models.Key words: reinforced concrete, edge connections, flat concrete plates, punching shear, shear strength, openings, failure, shear studs, shear reinforcement.


2008 ◽  
Vol 400-402 ◽  
pp. 335-340
Author(s):  
Xiao Wei Wang ◽  
Wen Ling Tian ◽  
Zhi Yuan Huang ◽  
Ming Jie Zhou ◽  
Xiao Yan Zhao

The thickness of the raft slab is determined by punching shear. The raft slab is commonly thick, which causes concrete volume is large. Mass concrete can bring disadvantage to the foundation. In order to increase the bearing capacity and reduce the thickness, it is suggested that the raft slab to be reinforced by steel fibers. There are five groups of specimens in this paper. S1 is the common reinforced concrete slab. S2 and S3 are concrete slabs reinforced by steel fibers broadcasted layer by layer when casting specimen. S4 and S5 are concrete slabs reinforced by steel fibers mixed homogeneously when making concrete. The punching shear tests of these slabs were done. The test results indicate that the punching shear capacity of the slab reinforced with steel fibers is higher than that of concrete slab, the stiffness and crack resistance of the steel fibers reinforced concrete slab are better than those of the common concrete slab and the punching shear of the slabs with different construction methods of steel fibers is similar. It analyses the punching shear behavior of the slab reinforced with steel fibers and suggests the ultimate bearing formula. The calculative values are coincided with the measured values well.


Author(s):  
Jukka Kähkönen ◽  
Pentti Varpasuo

Reinforced concrete wall subjected to an impact by a hard steel missile with a mass of 47 kg and an impact velocity of 135 m/s was one case study in the IRIS 2010 benchmark exercise in OECD/NEA/CSNI/IAGE framework. The wall had dimensions of 2m × 2m × 0.25m and it was simply supported. The perforation of the missile was expected. Fortum Power and Heat Ltd. participated in the benchmark. In this paper, we present our modeling and blind prediction of the benchmark case. The test results of the benchmark were released after the predictions were made. Based on the result comparison, we concluded that our model gave conservative results.


2002 ◽  
Vol 29 (4) ◽  
pp. 602-611 ◽  
Author(s):  
Ehab F El-Salakawy ◽  
Maria Anna Polak ◽  
Khaled A Soudki

The paper presents work on punching shear rehabilitation and strengthening of existing slab–column connections. Four full-scale specimens representing slab–column edge connections were built and tested to failure. Three slabs were then repaired and strengthened and tested again. In the originally tested slabs, which were chosen for repair, one slab had an opening in front of the column and contained shear reinforcement, one slab had an opening and no shear reinforcement, and one had no opening and no reinforcement. The dimensions of the slabs were 1540 × 1020 × 120 mm with square columns (250 × 250 mm). The openings in the specimens were square (150 × 150 mm) with the sides parallel to the sides of the column. The slabs were made using normal weight concrete (28-day average compressive strength of 32 MPa) and reinforced with a reinforcement ratio of 0.75%. The slabs were repaired by replacing old-damaged concrete with new concrete of the same properties. Strengthening was carried out using shear studs for the two slabs, which originally did not have shear reinforcement. The rehabilitation increased the punching shear strength (by 26–41%) and the ductility of the connections. All repaired specimens failed in flexure.Key words: concrete slabs, punching shear, rehabilitation, edge connections, openings, studs, repair.


2021 ◽  
Vol 11 (3) ◽  
pp. 4-13
Author(s):  
Zulfat Sh. GALYAUTDINOV

Here is the description of fi nite elementmodels of joints between reinforced concrete slab and column, made in the SIMULIA ABAQUS software package. The variable parameters were the ratio of the sides of the column cmax/cmin and the ratio of the side of the column to the eff ective depth c/h0. The calculation is performed in a non-linear formulation. Finite elementmodels showed realistic behavior: a punching shear pyramid was detected. It was found a signifi cant unevenness in the distribution of tangential deformations, as well as the main compressive deformations of the concrete slab near the column. The nature of the formation and development of the punching shear pyramid depends on the value of the ratio of the sides of the column cmax/cmin and the ratio of the side of the column to the eff ective depth slab c/h0.


Author(s):  
Hamid Abdulmahdi Faris ◽  
Lubna Mohammed Abd

The "flat slab" is a reinforced concrete slab bolstered, by a number of columns. Punching, shear is a category for collapse for reinforced concrete slabs exposed to great confined forces. In "flat slab" constructions the shear failure happens, at column bolster joints. To avoid this, collapse two methods are used, first method is increasing the column dimensions and, the other is to use drop panel if the first method leads to uneconomical, design. Two examples are used to find the effect, of column dimensions, increase on the punching shear failure of "flat slab". The first example, is a "flat slab" of span (5 by 5) m and the other is of span (6 by 6) m. The column which examined is the interior, edge and corner columns, and the interior column is the most dangerous case. It is concluded that, the increase of column dimensions are lead to avoid of punching shear failure in "flat slab" and the drop panel is enlarge the area of the critical shear perimeter and this avoiding punching shear failure.


2020 ◽  
Vol 23 (1) ◽  
pp. 1-11
Author(s):  
Ali H. Yaagoob ◽  
Ibrahem S. Harba

Reinforced concrete slab with plastic voids (Bubbled Deck system) is a new type of slabs which has two-dimensional arrangement of voids within the slab that is developed to decrease the slab self-weight while maintaining approximately the same load carrying capacity as compared with the solid slabs. Plastic voided slabs have the ability to reduce concrete amount by about 30 percent and this reduction is so important in terms of cost saving and enhancement the structural performance. In this research paper investigation is carried out to study the shear strength behavior of one-way bubble deck slab using self-compacting reinforced concrete. The experimental program consists of testing thirteen one-way slabs with dimensions of (1700 length, 700 width and 150 thick) mm. One of the tested slabs is a solid slab (without balls) is used as a reference, the remaining twelve bubbled slabs with ball diameter (73, 60) mm are divided into five groups according to the parameters of the experimental work, the parameters of the experimental work include: type of slab (bubble and solid slabs), ball diameter (73, 60) mm, shear reinforcement and spacing between balls. The experimental results showed that the bubbled slabs without shear reinforcement have a decrease in the ultimate load as compared to solid slab by about 3.7% to 14.3% and an increase in the deflection at ultimate load by about 10% to 22%, at the same time the first crack load decreases by about 15.3% to 42.4% as compared to solid slab due to decreases of moment of inertia of bubble slab compared to solid slab. Also, the results showed that the bubbled slabs withe shear reinforcement (multi-leg) have an increase in the ultimate load as compared to solid slab by about 35.4% to 57.3% and an increase in the deflection at ultimate load by about 1% to 15%, at the same time the first crack load decreases by about 2.8% to 27.4% as compared to solid slab.


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