Slip Dowel Placement System for Concrete Joints

Solution Overview

Problem

Existing methods for placing slip dowels in concrete slabs are labor-intensive, costly, and often result in improper alignment, leading to issues like cracking, faulting, and unevenness at cold joints.

Innovation Solution

A concrete dowel placement system comprising a coupler formed by extruding polymers to create tubular elements with different dimensions, and a sheath that is slidably extensible over the coupler to frictionally engage it, allowing for accurate and efficient placement of slip dowels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional drilling and manual placement methods are used for slip dowels, then flexibility and adaptability are maintained, but labor intensity increases, placement accuracy decreases, and time consumption increases

Engineering Contradiction:

Improvedowel alignment accuracyVSAvoidplacement time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The formwork is pre-equipped with dowel placement devices (tubes or molds) before concrete pouring. These devices are positioned in advance to ensure precise alignment, and the dowels are placed through these pre-positioned guides during the pouring process, eliminating the need for post-pour drilling and manual alignment adjustments.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Tubes or molds are introduced as intermediary components between the formwork and the slip dowels. These intermediaries guide the dowels into precise positions during concrete pouring, ensuring accurate alignment while simplifying the placement process. The tubes/molds serve as temporary mediators that are later removed after serving their positioning function.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If traditional drilling and manual placement methods are used for slip dowels, then adaptability to different site conditions is maintained, but labor costs and placement inconsistency increase

Engineering Contradiction:

Improvedowel placement precisionVSAvoidsystem complexity

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The dowel placement device is merged with the formwork structure itself. The tubes or molds are integrated into the formwork panels, creating a unified system that simplifies manufacturing. This integration ensures precise dowel placement without requiring separate, complex positioning equipment, thereby maintaining ease of manufacture while achieving high placement precision.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If slip dowels are not properly aligned, then installation simplicity is maintained, but structural reliability decreases due to cracking and faulting at cold joints

Engineering Contradiction:

Improvecold joint integrityVSAvoidplacement system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The formwork is pre-equipped with dowel placement devices (tubes or molds) before concrete pouring. These devices are positioned in advance to ensure precise alignment, and the dowels are placed through these pre-positioned guides during the pouring process, eliminating the need for post-pour drilling and manual alignment adjustments.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Tubes or molds are introduced as intermediary components between the formwork and the slip dowels. These intermediaries guide the dowels into precise positions during concrete pouring, ensuring accurate alignment while simplifying the placement process. The tubes/molds serve as temporary mediators that are later removed after serving their positioning function.

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system enables easy and accurate placement of slip dowels, reducing labor and costs while minimizing the risk of improper alignment, thus preventing cracking, faulting, and unevenness at cold joints.

Implementation Method 1

a sheath that is slidably extensible over the coupler to frictionally engage one of the first tubular element and the second tubular element

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

constructing a coupler includes the step of extruding a polymer to form a first tubular element

Methodology Applied

Scientific EffectExtrusion: Extrusion

Data Source

PatentUS12320076B2Concrete dowel placement system and method of making the same

Publication Date: 2025.06.03 SHAW & SONS

AI summary

A concrete dowel placement system and methods for making the same. The system allows for accurate and easy substantially-parallel or parallel placement of slip dowels within sections of concrete so that adjacent sections of concrete may be allowed to undergo thermal expansion and contraction while remaining in a common plane without cracking or faulting. The system includes a coupler and a sheath. The sheath is configured to be slidably extensible over the coupler and may be held to the coupler by friction. An outer surface of the sheath may be textured. Additionally, a method of constructing the concrete dowel placement system includes extruding material to form two tubes of different sizes. The tubes are then attached to each other, then material is extruded or injection molded to form a sheath. Alternatively, construction may include extruding material to form a tube, then removing some of the material from the tube in order to form a coupler.