Asphalt Composition Stabilizing Ground Tire Rubber Settling

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Solution Overview

Problem

Existing methods for blending ground tire rubber (GTR) with asphalt suffer from the settling of rubber particles, requiring continuous agitation to maintain distribution, which is inefficient and impractical.

Innovation Solution

A method involving blending GTR with asphalt bitumen at high temperatures and using a GTR stabilizer, such as KOMAXX, to create a shear thinning medium that prevents settling, allowing GTR to remain suspended for at least 48 hours without mechanical agitation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If ground tire rubber is blended with asphalt using conventional methods, then the rubber particles will settle out of the blend, but continuous agitation is required to maintain distribution

Engineering Contradiction:
Improvestability of GTR distribution in asphaltVSAvoidneed for continuous agitation
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

A dispersant is introduced as an intermediary substance to facilitate the interaction between GTR particles and asphalt. The dispersant adsorbs onto the GTR particle surfaces and provides steric or electrostatic repulsion, preventing particle aggregation and settling while maintaining uniform distribution throughout the asphalt matrix without requiring continuous mechanical agitation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the rheological parameters of the asphalt-GTR blend by adding a dispersant that changes the viscosity and flow characteristics of the mixture. This parameter change creates a shear-thinning effect where the mixture remains fluid during application but becomes more viscous at rest, preventing GTR settlement while ease of operation during paving.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If ground tire rubber is added to asphalt, then performance improvement is achieved, but the rubber particles tend to aggregate and settle

Engineering Contradiction:
Improveperformance reliability of road surfaceVSAvoiduniformity of GTR distribution
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The dispersant acts as a mediator between GTR particles and asphalt, creating stable suspensions that maintain uniform distribution. This prevents aggregation and settling, ensuring consistent performance characteristics throughout the paved surface while maintaining reliable structural and functional properties.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite material system consisting of GTR particles, dispersant, and asphalt working together. The dispersant-GTR-asphalt composite structure prevents phase separation and aggregation, maintaining homogeneous distribution of rubber particles throughout the asphalt matrix, which ensures consistent performance reliability across the entire road surface.

Inventive Principle:
Principle #40Composite materials

3Reliability

If high concentrations of ground tire rubber are used, then noise reduction and durability improve, but handling and application become more difficult

Engineering Contradiction:
Improvedurability and noise reduction performanceVSAvoidhandling and application ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The dispersant fundamentally changes the rheological parameters of the high-GTR-concentration mixture, reducing viscosity during mixing and paving operations while maintaining stability during storage and after placement. This allows high concentrations of GTR (improving noise reduction and durability) to be handled and applied as easily as conventional asphalt mixtures.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic rheological properties to the asphalt-GTR blend through the dispersant, creating a shear-thinning behavior where the mixture becomes less viscous under shear stress (during mixing and paving) and more viscous at rest (during storage and after placement). This dynamic property adjustment enables high GTR concentrations to be easily handled during application while maintaining stable suspension without settlement.

Inventive Principle:
Principle #15Dynamics

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 method effectively stabilizes GTR in asphalt, preventing settling and enabling increased GTR concentrations, improving the durability and noise reduction of road surfaces while facilitating easier handling and application.

Implementation Method 1

using a GTR stabilizer, such as KOMAXX, to create a shear thinning medium that prevents settling

Methodology Applied
Scientific EffectShear thinning: Shear Thinning

Data Source

PatentUS9212264B2Asphalt composition containing ground tire rubber
Publication Date: 2015.12.15 BEI IP

AI summary

We disclose a method of making an asphalt composition containing large quantities of ground tire rubber. Over 20% GTR by weight can be used in the asphalt composition without the GTR settling out. The method comprises a series of heating and blending and using a GTR stabilizer.