DEFLECTION RESPONSE OF REINFORCED CONCRETE SLABS TESTED IN PUNCHING SHEAR IN FIRE

Applications of Structural Fire Engineering ◽

10.14311/asfe.2015.031 ◽

2016 ◽

Author(s):

Holly Smith ◽

Tim Stratford ◽

Luke Bisby

Keyword(s):

Reinforced Concrete ◽

Heat Source ◽

Punching Shear ◽

Concrete Slabs ◽

Fire Exposure ◽

Flat Slab ◽

Combined Load ◽

Reinforced Concrete Slabs ◽

In Fire

Flat slab-column punching shear specimens were tested under combined load and fire exposure, with varying edge restraint conditions. The slabs deflected away from the heat source (in the direction of loading) at all stages of the tests. This paper examines this unusual deflection behaviour, although no definitive reason for this unexpected behaviour has been found.

Download Full-text

Effect of Column Dimensions on the Punching Shear of Flat Slab

International Journal of Scientific Research in Science Engineering and Technology ◽

10.32628/ijsrset196452 ◽

2019 ◽

pp. 378-393

Author(s):

Hamid Abdulmahdi Faris ◽

Lubna Mohammed Abd

Keyword(s):

Reinforced Concrete ◽

Shear Failure ◽

Concrete Slab ◽

The Other ◽

Punching Shear ◽

Concrete Slabs ◽

Reinforced Concrete Slab ◽

Flat Slab ◽

Interior Edge ◽

Reinforced Concrete Slabs

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.

Download Full-text

Critical shear crack theory-based punching shear model for FRP-reinforced concrete slabs

Advances in Structural Engineering ◽

10.1177/1369433220978146 ◽

2020 ◽

pp. 136943322097814

Author(s):

Xing-lang Fan ◽

Sheng-jie Gu ◽

Xi Wu ◽

Jia-fei Jiang

Keyword(s):

Shear Strength ◽

Reinforced Concrete ◽

Shear Crack ◽

Concrete Strength ◽

Weight Ratio ◽

Punching Shear ◽

Concrete Slabs ◽

Crack Theory ◽

Reinforced Concrete Slabs ◽

Rc Slabs

Owing to their high strength-to-weight ratio, superior corrosion resistance, and convenience in manufacture, fiber-reinforced polymer (FRP) bars can be used as a good alternative to steel bars to solve the durability issue in reinforced concrete (RC) structures, especially for seawater sea-sand concrete. In this paper, a theoretical model for predicting the punching shear strength of FRP-RC slabs is developed. In this model, the punching shear strength is determined by the intersection of capacity and demanding curve of FRP-RC slabs. The capacity curve is employed based on critical shear crack theory, while the demand curve is derived with the help of a simplified tri-linear moment-curvature relationship. After the validity of the proposed model is verified with experimental data collected from the literature, the effects of concrete strength, loading area, FRP reinforcement ratio, and effective depth of concrete slabs are evaluated quantitatively.

Download Full-text

Punching shear mechanism of reinforced concrete slabs with corroded reinforcing bars

Life-Cycle of Civil Engineering Systems - Life-Cycle of Structural Systems ◽

10.1201/b17618-186 ◽

2014 ◽

pp. 1257-1264

Author(s):

Y Tanaka ◽

T Sudoh

Keyword(s):

Reinforced Concrete ◽

Punching Shear ◽

Concrete Slabs ◽

Reinforcing Bars ◽

Shear Mechanism ◽

Reinforced Concrete Slabs

Download Full-text

Deformations of R.C.Circular Slabs in Fire Condition

Civil Engineering Journal ◽

10.28991/cej-0309126 ◽

2018 ◽

Vol 4 (4) ◽

pp. 712 ◽

Cited By ~ 1

Author(s):

Abdelraouf Tawfik Kassem

Keyword(s):

Finite Element ◽

Reinforced Concrete ◽

Slenderness Ratio ◽

High Surface ◽

High Surface Area ◽

Concrete Slabs ◽

Finite Element Models ◽

Reinforced Concrete Slabs ◽

Fire Condition ◽

In Fire

Reinforced concrete slabs are elements in direct contact with superimposed loads, having high surface area and small thickness. Such a condition makes slabs highly vulnerable to fire conditions. Fire results in exaggerated deformations in reinforced concrete slabs, as a result of material deterioration and thermal induced stresses. The main objective of this paper is to deeply investigate how circular R.C. slabs, of different configurations, behave in fire condition. That objective has been achieved through finite element modelling. Thermal-structural finite element models have been prepared, using "Ansys". Finite element models used solid elements to model both thermal and structural slab behaviour. Structural loads had been applied, representing slab operational loads, then thermal loads were applied in accordance with ISO 843 fire curve. Outputs in the form of deflection profile and edge rotation have been extracted out of the models to present slab deformations. A parametric study has been conducted to figure out the significance of various parameters such as; slab depth, slenderness ratio, load ratio, and opening size; regarding slab deformations. It was found that deformational behaviour differs significantly for slabs of thickness equal or below 100 mm, than slabs of thickness equal or above 200 mm. On the other hand considerable changes in slabs behaviour take place after 30 minutes of fire exposure for slabs of thickness equals or below 100 mm, while such changes delay till 60 minutes for slabs of thickness equals or above 200 mm.

Download Full-text