Prefabricated UHPC Link Slabs for Bridge Joints

Solution Overview

Problem

Current bridge deck joint systems are prone to leakage, leading to premature deterioration due to chloride penetration, and the cast-in-place Ultra High-Performance Concrete (UHPC) method is costly and time-consuming, unsuitable for short bridge closures.

Innovation Solution

Prefabricated Link Slabs made from UHPC, designed and manufactured in a factory environment with a debonding layer and reinforcing bars, offering superior durability and faster, cost-effective installation compared to traditional cast-in-place methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cast-in-place UHPC link slabs are used, then durability and resistance to chloride penetration are improved, but construction time and cost increase significantly

Engineering Contradiction:

ImprovedurabilityVSAvoidconstruction time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The link slabs are precast in a factory environment before installation, allowing quality control and curing to occur under controlled conditions. This preliminary fabrication eliminates the need for time-consuming on-site casting and curing operations, reducing construction time while maintaining the durability benefits of UHPC.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention replaces the traditional cast-in-place construction system with a precast fabrication and installation system. This substitution eliminates the need for formwork, on-site mixing, and extended curing periods, significantly reducing construction time while maintaining structural integrity and durability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If cast-in-place UHPC link slabs are used, then durability and resistance to chloride penetration are improved, but mobilization and quality control costs increase

Engineering Contradiction:

ImprovedurabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The link slabs are precast in a factory environment before installation, allowing quality control and curing to occur under controlled conditions. This preliminary fabrication eliminates the need for time-consuming on-site casting and curing operations, reducing construction time while maintaining the durability benefits of UHPC.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention replaces the traditional cast-in-place construction system with a precast fabrication and installation system. This substitution eliminates the need for formwork, on-site mixing, and extended curing periods, significantly reducing construction time while maintaining structural integrity and durability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If traditional deck joint systems are used, then installation is simpler and faster, but leakage and chloride penetration occur leading to premature deterioration

Engineering Contradiction:

Improveinstallation speedVSAvoidleak resistance

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The link slabs are constructed using Ultra High-Performance Concrete (UHPC), a composite material with superior durability and leak resistance properties. The UHPC composition includes carefully selected aggregates, cementitious materials, and admixtures that create a dense, impermeable structure resistant to chloride penetration and moisture ingress, eliminating the leakage problems of traditional joint systems.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The invention changes the material parameters from conventional concrete to UHPC, achieving significantly improved durability and leak resistance. The UHPC material properties include higher compressive strength, lower permeability, and enhanced resistance to chemical attack, which prevent chloride penetration and extend service life while maintaining installation efficiency.

Inventive Principle:

Principle #35Parameter changes

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 Prefabricated Link Slabs provide enhanced durability and resistance to moisture and chloride penetration, reducing maintenance needs and installation costs while allowing for quicker bridge repairs.

Implementation Method 1

a first debonding layer (2) attached to a bottom surface of the prismatic portion (1)

Methodology Applied

Scientific EffectDebonding:

Implementation Method 2

The strain hardening property of UHPC enables LS-USPC to meet the maximum rotational demand by producing multitudes of tight cracks that are impermeable to moisture and chlorides

Methodology Applied

Scientific EffectStrain hardening:

Data Source

PatentUS11851869B2Pre-fabricated link slab—ultra high performance concrete

Publication Date: 2023.12.26 ROYCE MATHEW CHIRAPPURAM

AI summary

Disclosed invention comprises innovations related to the fabrication process and the associated design of Prefabricated Link Slabs made using Ultra High-Performance Concrete (UHPC) for bridges hereinafter referred as PLS-UHPC. This disclosure is regarding methods of designing, manufacturing, and installing PLS-UHPC as connections between bridge spans. The invention includes the concept of installing PLS-UHPC which will provide numerous benefits such as faster construction in the field, and better maintenance of established systems.