Name: sizing steel bars for a concrete beam
Uploaded: 2024-11-07T14:48:55.000Z
Duration: 1 min 22 s
Channel: JoVE

K12 Standards

Texas Essential Knowledge and Skills

High School

Biology

BIO.2

BIO.2.D

design-example-distributing-reinforcements-in-concrete-sections

Design Example: Distributing Reinforcements in Concrete Sections

Considérons une section transversale de poutre en béton armé pour laquelle la section d’armature requise est égale à 4 pouces carrés selon la conception de l’armature.
Des barres d’un diamètre nominal de 1,693 pouce sont disponibles en stock.
Maintenant, l’ingénieur doit ajuster les barres de diamètre disponible pour répondre à la section transversale d’acier souhaitée de quatre pouces carrés.
La section transversale d’une barre de 1,693 pouce de diamètre est de 2,25 pouces carrés et le nombre de barres sera de 1,777. Ce nombre sera arrondi au nombre entier le plus proche, c’est-à-dire 2.
La section transversale totale des 2 barres de diamètre 1,693 pouces serait égale à 4,5 pouces carrés.
Une section transversale supplémentaire de 0,5 pouce carré est fournie pour répondre à la section transversale souhaitée avec les barres disponibles.
Si le stock disponible a des barres d’un diamètre égal à 1,128 pouce, l’aire de la section transversale de cette barre est de 1 pouce carré, ce qui signifie qu’exactement 4 barres suffiraient pour les exigences de conception de la section transversale de l’acier.

exemple de conception: répartition des armatures dans les sections en béton

Le sujet explore les aspects pratiques de l'ajustement des armatures en acier dans une section de poutre en béton pour répondre à des exigences de conception spécifiques. Lors de la conception d'une poutre en béton armé, il est essentiel de répartir correctement les armatures en acier pour garantir l'intégrité et l'efficacité structurelles. L'exemple fourni détaille un scénario dans lequel une poutre nécessite une section transversale totale en acier de 25,81 centimètres carrés. L'ingénieur identifie que les barres d'acier disponibles ont un diamètre nominal de 4,30 centimètres, chacune offrant une section transversale de 14,52 centimètres carrés.


 Le calcul du nombre de barres nécessaires donne un nombre non entier, qui doit être arrondi au nombre entier le plus proche, ce qui entraîne un léger excédent d'acier fourni. Par ailleurs, si des barres d'un diamètre de 2,87 centimètres sont utilisées, 4 barres répondraient exactement à l'exigence, car chaque barre contribue à 6,45 centimètres carré de la section transversale. Ce scénario illustre l'importance de sélectionner la taille et le nombre de barres appropriés pour répondre aux spécifications de conception sans gaspillage majeur de matériaux ni compromis structurel. De telles décisions sont essentielles dans les projets de construction pour maintenir les contraintes budgétaires et assurer la sécurité structurelle. Une planification et des calculs appropriés permettent une utilisation efficace des matériaux tout en respectant les normes d'ingénierie.

Exemple de conception: répartition des armatures dans les sections en béton

Considérons une section transversale de poutre en béton armé pour laquelle la section d’armature requise est égale à 4 pouces carrés selon l’armature ...

Education

Enseignement

JoVE Core

Civil Engineering

Génie civil

Unit 1

Unité 1

Design Examples

Exemples de conception

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

sizing steel bars for a concrete beam

Sizing steel bars for a concrete beam helps meet a required reinforcement area. In reinforced concrete design, the steel must be arranged so the beam stays strong and uses material efficiently. This example uses a beam that needs a total steel cross-section of 4 square inches.

The available bars in the example have a nominal diameter of 1.693 inches. Each bar provides a cross-sectional area of 2.25 square inches. When the engineer divides the required area by the area of one bar, the result is not a whole number.

That answer must be rounded up to the next whole bar, so the beam receives a small amount of extra steel. The example also shows a second option. Bars with a diameter of 1.128 inches each provide 1 square inch of cross-sectional area, so 4 bars meet the 4-square-inch requirement exactly.

This comparison shows why bar size and bar count matter in concrete beam design. Choosing the right combination can reduce wasted material and still meet the design specification. These calculations help support structural safety and budget control in construction projects.

Sizing Steel Bars for a Concrete Beam

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design-example-dimensioning-of-concrete-masonry-construction

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design-example-joints-in-concrete-pavements

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design-example-managing-concrete-workability

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design example: distributing reinforcements in concrete sections

Sizing steel bars for a concrete beam helps meet a required reinforcement area. In reinforced concrete design, the steel must be arranged so the beam stays strong and uses material efficiently. This example uses a beam that needs a total steel cross-section of 4 square inches. The available bars in the example have a nominal diameter of 1.693 inches. Each bar provides a cross-sectional area of 2.25 square inches. When the engineer divides the required area by the area of one bar, the result is...

design example: sustainability in concrete building

design-example-sustainability-in-concrete-building

Green Features in a Concrete Building

A sustainable concrete building can use several green design features to save energy, water, and materials. Concrete is a flexible material for these choices, so it supports eco-friendly construction in commercial buildings. One strategy is to place a concrete parking area under the building. Open areas can use pervious concrete paver blocks, which let rainwater pass through and collect in an underground cistern. That stored water can then be reused for gardening, which improves water...

key terms and concepts

See how engineers choose steel bar size and count to meet a 4-square-inch reinforcement target in a concrete beam while limiting waste and meeting design needs.

Sizing Steel Bars for a Concrete Beam | JoVE K12

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Sizing Steel Bars for a Concrete Beam

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