STUDIES OF DEFLECTION OF REINFORCED CONCRETE SLABS UNDER SUSTAINED LOADS

1986 ◽  
Vol 365 (0) ◽  
pp. 165-174
Author(s):  
TOSHIKAZU TAKEDA ◽  
SUNAO NAKANE ◽  
MITSUO KOYANAGI
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
Sustained Loads

scholarly journals Effect of the Geometrical Constraints to the Wenner Four-Point Electrical Resistivity Test of Reinforced Concrete Slabs

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4622
Author(s):  
Kevin Paolo V. Robles ◽  
Jurng-Jae Yee ◽  
Seong-Hoon Kee
Keyword(s):  
Experimental Investigation ◽  
Electrical Resistivity ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Plain Concrete ◽  
Electrode Spacing ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
Spacing Ratio ◽  
Geometrical Constraints

The main objectives of this study are to evaluate the effect of geometrical constraints of plain concrete and reinforced concrete slabs on the Wenner four-point concrete electrical resistivity (ER) test through numerical and experimental investigation and to propose measurement recommendations for laboratory and field specimens. First, a series of numerical simulations was performed using a 3D finite element model to investigate the effects of geometrical constraints (the dimension of concrete slabs, the electrode spacing and configuration, and the distance of the electrode to the edges of concrete slabs) on ER measurements of concrete. Next, a reinforced concrete slab specimen (1500 mm (width) by 1500 mm (length) by 300 mm (thickness)) was used for experimental investigation and validation of the numerical simulation results. Based on the analytical and experimental results, it is concluded that measured ER values of regularly shaped concrete elements are strongly dependent on the distance-to-spacing ratio of ER probes (i.e., distance of the electrode in ER probes to the edges and/or the bottom of the concrete slabs normalized by the electrode spacing). For the plain concrete, it is inferred that the thickness of the concrete member should be at least three times the electrode spacing. In addition, the distance should be more than twice the electrode spacing to make the edge effect almost negligible. It is observed that the findings from the plain concrete are also valid for the reinforced concrete. However, for the reinforced concrete, the ER values are also affected by the presence of reinforcing steel and saturation of concrete, which could cause disruptions in ER measurements

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

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.

scholarly journals Case study on the mineralogical and petrophysical analysis of reinforced concrete slabs of a highway viaduct of the S.G.C. Orte-Ravenna

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Elena Marrocchino ◽  
Chiara Telloli ◽  
Alessandra Aprile ◽  
Domenico Capuani ◽  
Davide Malaguti ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slabs ◽  
Petrophysical Analysis ◽  
Reinforced Concrete Slabs

Influence of fiber orientation on the behavior of fiber reinforced concrete slabs

2021 ◽  
Author(s):  
Antonio Conforti ◽  
Estefania Cuenca ◽  
Raúl Zerbino ◽  
Giovanni A. Plizzari
Keyword(s):  
Reinforced Concrete ◽  
Fiber Orientation ◽  
Fiber Reinforced Concrete ◽  
Concrete Slabs ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slabs

Chloride penetration into reinforced concrete slabs

1998 ◽  
Vol 25 (1) ◽  
pp. 87-95 ◽  
Author(s):  
A K Suryavanshi ◽  
R N Swamy ◽  
S McHugh
Keyword(s):  
Reinforced Concrete ◽  
Surface Coating ◽  
Lateral Diffusion ◽  
Chloride Penetration ◽  
Chloride Diffusion ◽  
Concrete Slabs ◽  
Coating System ◽  
Depth Of Penetration ◽  
Lateral Direction ◽  
Reinforced Concrete Slabs

The overall aim of this paper is to establish the process and amount of chlorides penetrating reinforced concrete elements when exposed to a salt-laden environment. For this purpose, a number of slabs were subjected to 70 cycles of wetting-drying regime with a 4% sodium chloride solution over a period of 2-3 years. To examine the direction of transportation of the chlorides, some of the slabs were partially coated with a surface coating system known to be highly resistant to chloride penetration. The amount and depth of penetration of chlorides in the coated and uncoated parts of the slab were then determined. The results show conclusively that, in large exposed areas of concrete, chlorides diffuse both in the direction of depth and in a direction lateral to the depth of the element. The amount of chlorides and the distance of their lateral diffusion depend on the water-to-cement (w/c) ratio of the concrete and the duration of exposure. Concrete mixes with a high w/c ratio (0.75) are highly conducive to this lateral diffusion of chlorides. Although concrete mixes of lower w/c ratios (0.45 and 0.60) are less conducive to lateral diffusion of chlorides, in practice, all concretes should be considered to be prone to chloride diffusion in both the direction of gravity and the lateral direction because of the effects of cracking. In unprotected concrete, reducing the w/c ratio from 0.60 to 0.45 is far more effective in decreasing chloride penetration than that achieved by reducing the w/c ratio from 0.75 to 0.60. The acrylic-based surface coating system is totally resistant to chloride penetration.Key words: chloride diffusion, concrete slabs, durability, water-to-cement ratio, surface coating, lateral diffusion.

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