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

scholarly journals Arrangement of construction joints in cast-in-place slabs

2019 ◽  
Vol 97 ◽  
pp. 04023
Author(s):  
Irina Yakovleva ◽  
Valentina Kurochkina
Keyword(s):  
Reinforced Concrete ◽  
Strength Properties ◽  
Concrete Slabs ◽  
Construction Joint ◽  
Regulatory Documents ◽  
Reinforced Concrete Slabs ◽  
Early Removal ◽  
Construction Joints ◽  
Under Construction

Within latest decades cast-in-place construction of residential houses has been actively developed. Works on erection of cast-in-place frame of the building are normally performed by phases, which results in a necessity to arrange construction joints of concreting. In accordance with regulatory documents, it is allowed to arrange construction joints in any place of the slab, in parallel with its less side. As well, it is necessary to observe the technology for joint arrangement. As practice shows, observing only technology of construction joint arrangement is insufficient to provide for strength properties of cast-in-place reinforced-concrete slabs. This article provides an analysis of actual geodetic pre-construction surveys, design and theoretically-calculated solutions; case study is a multistoried building under construction. On which basis, excessive slab deflections in the places of construction joints, were detected. It is established, that the main reason for deflection occurrence is early removal of slab formwork and installation of supports for temporary supporting. On the basis of obtained findings authors make conclusions regarding compulsory observance of the technology for construction joint arrangement, regarding a necessity to remove formwork according to common standards 70.13330.2012; as well, it is recommended to leave formwork under construction joints until concrete gains 100% of ruggedness.

scholarly journals ANALYSIS FOR IMPLEMENTING GREEN ROOFS ON REINFORCED CONCRETE SLABS. A CASE STUDY IN THE CITY OF TUXTLA GUTIERREZ, CHIAPAS, MEXICO

2022 ◽  
Author(s):  
Víctor Manuel Sánchez Trujillo ◽  
Keyword(s):  
Reinforced Concrete ◽  
El Paso ◽  
Green Roofs ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
El Sistema ◽  
The City

En la búsqueda de asumir métodos que brinden un mejor confort en el sistema de vivienda, éstos requieren de mejores prestaciones estructurales en las edificaciones actuales. Las prácticas constructivas en la región se han ido desprestigiando con el paso del tiempo, concibiendo edificaciones vulnerables, que dejan expuesto a quienes las habitan. El objetivo de esta investigación fue analizar de forma integral las características técnicas, constructivas y de diseño de losas de concreto armado, en su implementación como estructura de soporte para techos verdes en la ciudad de Tuxtla Gutiérrez, Chiapas, México. Para realizar el análisis se consideraron las propiedades intrínsecas del miembro de soporte (losas), el estado actual en las que estas se encuentran y su diseño bajo regímenes de durabilidad. Tras realizar la investigación se encontró que los espesores de la losa y las cuantías de acero son menores para claros promedio, según lo estipulado por las normas técnicas correspondientes. Los daños por corrosión del acero son esperados y se encuentran bajo un régimen de diseño inadecuado, aunado a la deficiencia durante el proceso constructivo. Las construcciones analizadas y desarrolladas por procesos de construcción formal o de autoconstrucción evidencian patologías similares. La falta de centros de capacitación para los propietarios y los obreros que adopten los métodos de autoconstrucción, así como el poco rigor de las autoridades en el cumplimiento de los reglamentos de construcción se han convertido en una brecha del conocimiento clave. Finalmente, es poco probable la implementación de techos verdes en estas estructuras sin antes realizar cambios significativos en toda la construcción.

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.

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
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