Name: concrete pavement joint types and functions
Uploaded: 2025-06-13T10:43:57.000Z
Duration: 1 min 28 s
Channel: JoVE

Propõe-se a extensão de um pavimento de concreto liso existente para construção com lajes de concreto, garantindo o mínimo de rachaduras no pavimento.
Um engenheiro de pavimento decide fornecer juntas de construção, expansão, isolamento e contração para controlar rachaduras no pavimento.
As juntas de construção são lacunas fornecidas entre a nova laje e uma laje existente para permitir quaisquer movimentos possíveis na nova laje. Barras de cavilha embutidas no concreto unem as lajes adjacentes.
As juntas de dilatação são vãos fornecidos entre as lajes adjacentes para permitir a expansão térmica do concreto.
Sua construção envolve a disposição das barras de cavilha em fileiras na direção transversal do pavimento e o despejo de concreto sobre as barras.
A lacuna deixada é então preenchida com cargas compressíveis e selantes.
As juntas de isolamento são fornecidas onde o pavimento encontra um bueiro. Uma junta de meia polegada de largura ao redor do bueiro, preenchida com um material compressível, forma a junta de isolamento.
Finalmente, a junta de contração é fornecida serrando uma ranhura no pavimento de concreto recentemente endurecido orientada perpendicularmente à direção do fluxo de tráfego.
Isso ajuda a localizar e controlar a formação de rachaduras durante a contração do concreto.

exemplo de projeto: juntas em pavimentos de concreto

Design Example: Joints in Concrete Pavements

As juntas de pavimento de concreto são essenciais para manter a integridade estrutural e a longevidade do pavimento, controlando onde e como o pavimento racha. Essas juntas podem ser categorizadas com base em suas funções, como juntas de contração ou controle, juntas de construção, juntas de isolamento e juntas de expansão.

As juntas de contração são normalmente formadas ao serrar uma ranhura no concreto logo após ele ter endurecido. Isso cria um plano vertical enfraquecido, incentivando deliberadamente a fissuração neste local predeterminado em vez de aleatoriamente na laje de concreto.

As juntas de isolamento são usadas onde um pavimento de concreto encontra outra superfície ou um objeto fixo, como uma interseção de rodovia ou um dispositivo de utilidade como um bueiro. Essas juntas incluem um material compressível que preenche toda a profundidade da junta, permitindo que estruturas ou superfícies adjacentes se movam independentemente do pavimento.

As juntas de construção ocorrem onde o concreto fresco encontra o concreto endurecido, geralmente visto no final de um dia de pavimentação. Essas juntas gerenciam transições entre diferentes seções do pavimento e embutem barras de pino ou tirantes entre as seções.

As juntas de expansão são empregadas para acomodar a expansão potencial de lajes de concreto. Essas juntas são cruciais para evitar o desenvolvimento de altas forças de compressão, o que pode levar à lascamento da junta ou explosões estruturais. Elas normalmente contêm dispositivos de transferência de carga, como pinos ou barras de tirante, que facilitam o movimento principalmente na direção da junta. Geralmente, as juntas são preenchidas usando materiais de enchimento e selantes.

Exemplo de projeto: juntas em pavimentos de concreto

Propõe-se a extensão de um pavimento de concreto liso existente para construção com lajes de concreto, garantindo o mínimo de rachaduras no pavimento.
Um pavimento ...

design-example-joints-in-concrete-pavements

Education

JoVE Core

Civil Engineering

Unit 1

Design Examples

KEY TERMS AND CONCEPTS

concrete pavement joint types and functions

Concrete pavement joints guide where slabs crack and help protect the pavement over time. They support the structural integrity and long life of the concrete by controlling movement and cracking.

Contraction joints, also called control joints, are made by sawing a groove into the concrete soon after it hardens. This groove creates a weakened vertical plane. It encourages cracking at a planned location instead of letting cracks form randomly across the slab.

Isolation joints are used where the pavement meets another surface or a fixed object. Common examples include a roadway intersection or a utility fixture such as a manhole. These joints use compressible material that fills the full depth of the joint, so the pavement and nearby structure can move independently.

Construction joints appear where fresh concrete meets hardened concrete, often at the end of a paving day. They handle the transition between sections of pavement. Dowel bars or tie bars are embedded between the sections to help connect them.

Expansion joints allow concrete slabs to expand without building up too much compressive force. That helps prevent joint spalling and structural blowups. These joints usually include load transfer devices such as dowels or tie bars, which support movement mainly along the joint direction. In general, joints are finished with filler materials and sealants.

Concrete Pavement Joint Types and Functions

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design example: joints in concrete pavements

Concrete pavement joints guide where slabs crack and help protect the pavement over time. They support the structural integrity and long life of the concrete by controlling movement and cracking. Contraction joints, also called control joints, are made by sawing a groove into the concrete soon after it hardens. This groove creates a weakened vertical plane. It encourages cracking at a planned location instead of letting cracks form randomly across the slab. Isolation joints are used where the...

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key terms and concepts

Learn how contraction, isolation, construction, and expansion joints control cracking, movement, and support in concrete pavements.

Concrete Pavement Joint Types and Functions | JoVE K12

JoVE Core Civil Engineering offers a foundational exploration of essential construction materials such as bricks, stones, steel, wood, and concrete, along with fluid mechanics topics like flow over immersed bodies, open channel flow, and dimensional modeling. It also covers key surveying concepts, including leveling, traverse adjustments, curve design, topographic mapping, and geospatial technologies (GPS & GIS). Science-in-action videos showcase laboratory research on materials, fluids, and surveying practices in real-world engineering systems.

Concrete Pavement Joint Types and Functions

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