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

既存のプレーンコンクリート舗装の拡張は、コンクリートスラブを使用した建設に提案されており、舗装のひび割れを最小限に抑えます。
舗装エンジニアは、舗装のひび割れを制御するために、建設、伸縮、分離、および収縮ジョイントを提供することを決定しました。
建設ジョイントは、新しいスラブと既存のスラブの間に設けられた隙間であり、新しいスラブで可能な動きを可能にします。コンクリートに埋め込まれたダボバーは、隣接するスラブを結び付けます。
伸縮継手は、コンクリートの熱膨張を可能にするために隣接するスラブ間に設けられた隙間です。
その構造には、舗装の横方向にダボバーを列に並べ、バーの上にコンクリートを流し込むことが含まれます。
その後、残った隙間を圧縮性フィラーとシーラントで埋めます。
舗装がマンホールに遭遇する場所には、アイソレーションジョイントが用意されています。マンホールの周りの半インチ幅のジョイントは、圧縮性材料で満たされ、アイソレーションジョイントを形成します。
最後に、収縮ジョイントは、最近硬化したコンクリート舗装に、交通の流れの方向に垂直に向けられた溝を鋸で挽くことによって提供されます。
これにより、コンクリートの収縮時の亀裂形成を局所化し、制御することができます。

設計例: コンクリート舗装ジョイント

コンクリート舗装ジョイントは、舗装の亀裂箇所と亀裂具合を制御することで、舗装の構造的完全性と耐久性を維持するために不可欠です。これらのジョイントは、収縮ジョイントまたは制御ジョイント、施工ジョイント、絶縁ジョイント、伸縮ジョイントなどの機能に基づいて分類できます。


 収縮ジョイントは通常、コンクリートが硬化した直後に溝を切ることによって形成されます。これにより、弱い垂直面が形成され、コンクリートスラブ全体にランダムに亀裂が生じるのではなく、この所定の場所で意図的に亀裂が生じやすくなります。


 絶縁ジョイントは、道路の交差点やマンホールなどの公共設備など、コンクリート舗装が別の表面や固定物と接する箇所で使用されます。これらのジョイントには、ジョイントの深さ全体を埋める圧縮可能な材料が含まれており、隣接する構造物や表面が舗装とは独立して移動できるようにします。


 施工ジョイントは、生コンクリートと硬化コンクリートが接合する場所で発生し、1 日の舗装作業の最後によく見られます。これらのジョイントは、舗装の異なるセクション間の移行を管理し、セクション間にダウエルバーまたはタイバーを埋め込みます。


 伸縮ジョイントは、コンクリートスラブの潜在的な膨張に対応するために使用されます。これらのジョイントは、ジョイントの剥離や構造の破裂につながる可能性がある高い圧縮力の発生を防ぐのに重要です。通常、ジョイントには、主にジョイントの方向への動きを促進するダウエルバーやタイバーなどの荷重伝達装置が含まれています。通常、ジョイントは充填材とシーラントを使用して充填されます。

既存のプレーンコンクリート舗装の拡張は、コンクリートスラブを使用した建設に提案されており、舗装のひび割れを最小限に抑えます。
舗装...

design-example-joints-in-concrete-pavements

Education

JoVE Core

Civil Engineering

土木工学

Unit 1

ユニット1

Design Examples

設計例

KEY TERMS AND CONCEPTS

主要用語と概念

Design Example: Joints in Concrete Pavements

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

design example: dimensioning of concrete masonry construction

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

Sizing a Storeroom with Masonry Blocks

Sizing a storeroom with concrete masonry blocks starts with matching the wall plan to the actual block size and mortar joints. The site has concrete masonry units with a nominal size of 8 by 8 by 16 inches. The storeroom is planned with external dimensions of 12 feet long and 8 feet wide. The wall layout uses nine blocks along the length and six blocks along the width. Each block is actually 7 and 5/8 inches high and wide, and 15 and 5/8 inches long. A 3/8 inch mortar joint is included, so the...

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...

design example: aggregate gradation

Choosing Well-Graded Sand for Concrete

Well-graded sand is important in concrete because aggregate choice affects strength, mix proportions, and cost. In concrete, sand is the common fine aggregate. When more than one sand source is available, its gradation often guides the selection. Gradation means the particle-size distribution of the sand. Engineers measure it with sieve analysis, which uses standard sieve sizes from 150 μm to 10 mm, from ASTM No. 100 to the 3/8 in. sieve. This test shows how much sand stays on each sieve and...

design example: managing concrete workability

design-example-managing-concrete-workability

Concrete Slump Test in Hot Weather

Concrete slump testing helps track workability during a raft foundation pour in hot weather. Workability means fresh concrete is easy to place, compact, and finish. In this example, the concrete had to be prepared for a large foundation, so keeping it workable was important for quality and durability. The first slump test showed low workability. The mix was losing water quickly, and the high temperature made the coarse aggregates hotter as well. To reduce that effect, the site engineer cooled...

design example: distributing reinforcements in concrete sections

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

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...

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

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 provides a foundational exploration of essential construction materials in civil engineering, focusing on bricks, stones, steel, wood, and concrete through easy-to-understand animated videos. This collection covers the properties, manufacturing processes, and practical applications of these materials. Additionally, the accompanied science-in-action videos demonstrate the research experiments performed in laboratories.

Concrete Pavement Joint Types and Functions

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