Grout to Grout Rebar Coupler with Segmented Internal Ribs

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Solution Overview

Problem

Existing rebar connectors for reinforced concrete structures face challenges in efficient grouting, off-gassing issues, and limited flexibility in prefabrication and installation, leading to reduced coupling strength and increased grout usage.

Innovation Solution

The development of a rebar connector with a coupler body featuring a hollow interior, grout ports, set screws, and internal ribs to align and secure rebars, along with a removable cap and stop assembly for improved grout distribution and reduced grout volume, enhancing prefabrication and on-site assembly processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If traditional rebar connectors are used, then coupling strength is achieved, but grout usage is excessive and off-gassing issues occur

Engineering Contradiction:
Improvegrout usageVSAvoidcoupling strength
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The hollow interior is divided into multiple cells by internal ribs, creating separate compartments for grout injection. This segmentation allows controlled grout distribution and reduces total grout volume needed while maintaining coupling strength through localized grout placement in critical areas.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Grout is selectively placed in specific cells rather than filling the entire hollow interior uniformly. The internal ribs create zones with different grout volumes, concentrating grout where it provides maximum bonding benefit while reducing overall grout consumption and minimizing off-gassing from excess grout.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If conventional coupler designs are used, then rebar connection is achieved, but flexibility in prefabrication and installation is limited

Engineering Contradiction:
Improveflexibility in prefabrication and installationVSAvoidgrouting efficiency
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

Rebars are positioned and secured within the coupler body before grout injection using set screws and internal ribs. This preliminary positioning ensures correct alignment and spacing, allowing efficient on-site assembly and reducing installation time while maintaining connection reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The coupler design allows for adjustable rebar positioning through removable set screws and flexible internal rib configurations. This dynamic adjustment capability provides versatility for different rebar sizes and installation scenarios while maintaining ease of grouting through the designated grout ports.

Inventive Principle:
Principle #15Dynamics

3Reliability

If grout is injected into traditional connectors, then rebar bonding is achieved, but off-gassing effects reduce connection quality

Engineering Contradiction:
Improveconnection qualityVSAvoidoff-gassing effects
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The internal ribs divide the grout injection space into separate cells, allowing controlled air escape paths and preventing trapped air pockets that cause off-gassing issues. Each cell can be independently filled, reducing pressure buildup and harmful gas formation during grout curing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design extracts and removes air pockets and excess grout through strategically positioned grout ports and cell configurations, preventing off-gassing from compromising the connection quality. The segmented structure allows air to escape during grout injection rather than being trapped.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4421261A1Grout to grout rebar coupler and method of prefabricating a concrete structure
Publication Date: 2024.08.28 ERICO INTERNATIONAL CORP
  • EP4421261A1 patent drawingFigure 1
  • EP4421261A1 patent drawingFigure 2
  • EP4421261A1 patent drawingFigure 3~4

AI summary

A rebar coupler (120) can have a coupler body (140) with a hollow interior, and a first end (150) and a second end (154) that are open to the hollow interior to receive rebar into opposing ends of the hollow interior along a longitudinal axis (LA). One or more grout ports can be included on the coupler body (140), including a first grout port (160) on the first end (150) of the coupler body (140). The coupler body (140) can include a set screw (142), a removable stop, a narrowed first end, a removable cap, or other features.