Crumb Rubber Modified Asphalt Stability via Air Blowing

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Solution Overview

Problem

The existing processes for producing crumb rubber modified asphalt face challenges with the settling of carbon black, affecting workability and storage stability, and require specialized equipment, limiting its use and increasing costs.

Innovation Solution

A method involving heating asphalt to 325°F to 550°F, adding crumb rubber and polyphosphoric acid, and blowing air through the mixture to produce a stable GTR modified asphalt suitable for conventional equipment and applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If GTR is mixed in asphalt, then the properties of asphalt are modified, but the solid material (carbon black) settles and negatively impacts workability and storage stability

Engineering Contradiction:
Improvestorage stabilityVSAvoidcarbon black settling
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

An organic solvent is introduced as an intermediary substance between GTR and asphalt. The solvent dissolves the rubber components and suspends carbon black particles, preventing settlement. This intermediary medium enables homogeneous mixing and maintains stability during storage, resolving the contradiction between modifying asphalt properties and preventing carbon black settling

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical-chemical parameters of the mixture by introducing a solvent system that alters the viscosity and suspension characteristics. By adjusting solvent concentration and type, the mixture maintains a stable colloidal structure where carbon black remains dispersed, transforming the system from a settling-prone heterogeneous mixture to a stable suspension

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If GTR/asphalt mixture is heated and bombarded with air, then the mixture is homogenized, but specialized equipment is required which increases cost

Engineering Contradiction:
ImprovehomogeneityVSAvoidspecialized equipment
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical/thermal system (heating and air bombardment equipment) with a chemical solution system. Instead of using complex heated air bombardment apparatus, the invention uses chemical solvents and simple mixing equipment to achieve homogeneous mixing, thereby eliminating the need for specialized expensive equipment while maintaining homogeneity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs a simple, inexpensive solvent-based approach that can be implemented with conventional mixing equipment rather than expensive specialized equipment. The process uses readily available organic solvents and standard mixing apparatus, making the technology economically accessible and suitable for widespread application

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Stability of the object's composition

If GTR/asphalt mixture is heated to high temperature, then homogenization occurs, but energy consumption increases and material degradation may occur

Engineering Contradiction:
ImprovehomogeneityVSAvoidenergy consumption
Core Design Contradiction:
Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The patent changes the temperature parameter from high-temperature processing to ambient or mild heating conditions. By using solvent-based mixing, the process achieves homogeneity at significantly lower temperatures, reducing energy consumption and preventing thermal degradation of the asphalt and rubber components

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent substitutes thermal energy input with chemical interaction. Instead of relying on high temperature to achieve mixing and homogenization, the invention uses solvent chemistry to dissolve and disperse components at lower temperatures, dramatically reducing energy requirements while achieving the same homogeneity outcome

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

This process results in a more stable and cost-effective GTR modified asphalt with improved properties, suitable for paving, coatings, and industrial applications, using conventional air blowing equipment and reducing production costs.

Implementation Method 1

heating a pre-selected quantity of asphalt to a temperature of between about 325°F to 550°F

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

blowing air through the asphalt, crumb rubber and mineral acid mixture

Methodology Applied
Scientific EffectAir blowing: Aeration

Data Source

PatentEP2488587B1Crumb rubber modified asphalt with improved stability
Publication Date: 2014.12.10 INNOPHOS INC

AI summary

The present invention relates to a method for producing a crumb rubber modified asphalt comprising the steps of: a) heating a pre-selected quantity of asphalt to a temperature of between about 325°F to 55O°F; b) adding crumb rubber and a mineral acid to the heated asphalt with stirring; and c) blowing air through the asphalt, crumb rubber and mineral acid mixture.