Ambient-Temperature Asphalt Mix Using Biodegradable Solvents
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Solution Overview
Problem
Existing asphalt mixes, both cold and hot, face issues with being workable at ambient temperatures, are often toxic due to petroleum solvents, and have environmental hazards, lacking biodegradable alternatives that can effectively use recycled asphalt products for patching applications.
Innovation Solution
An asphalt mix using pine extract and biodiesel as biodegradable solvents, combined with recycled asphalt products and anti-stripping agents, which is workable at ambient temperatures without machinery, eliminating petroleum solvents and allowing for stockpiling and bagging, with a method involving extended dry mixing to coat aggregates with asphalt cement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If petroleum solvents are used in cold mix asphalts to make them workable at ambient temperatures, then the asphalt becomes workable at ambient temperatures, but it becomes toxic and environmentally hazardous
Solution Approach 1:
The patent changes the chemical composition parameters by substituting petroleum solvents with biodegradable alternatives (vegetable oils, animal fats, waste cooking oils). This parameter change maintains the solvent function for workability while eliminating toxicity, directly resolving the contradiction between ease of operation and harmful factors
Solution Approach 2:
The patent converts waste materials (waste cooking oils, animal fats) into beneficial biodegradable solvents. These waste products, which would otherwise be harmful or useless, are transformed into environmentally safe solvents that provide the necessary workability without toxicity, addressing both sides of the contradiction
2Reliability
If hot mix asphalts are used for paving, then they provide good paving performance, but they require heating to 250-325 degrees F and heat safety precautions
Solution Approach 1:
The patent changes the temperature parameter by using biodegradable solvents that enable the asphalt to remain workable at ambient temperatures. The solvent system allows the asphalt to achieve proper consistency without thermal energy input, directly resolving the contradiction between reliability and temperature requirements
Solution Approach 2:
The biodegradable solvent acts as an intermediary substance that enables workability at low temperatures. Instead of using heat as the intermediary to achieve workability, the patent introduces biodegradable solvents as the mediating agent, eliminating the need for high temperature processing while maintaining paving performance
3Loss of substance
If recycled asphalt products are used in cold mix asphalts, then material efficiency improves, but the absorption of asphalt blend into aggregates increases, reducing effectiveness
Solution Approach 1:
The patent changes the chemical composition parameters of the solvent system by using biodegradable solvents with different absorption characteristics. These solvents modify the rheological properties of the asphalt blend, reducing excessive absorption into aggregates and improving the effectiveness of the recycled material, thus resolving the contradiction between loss of substance and reliability
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 asphalt mix is environmentally safe, non-toxic, and workable at ambient temperatures, reducing solvent absorption into aggregates, increasing the effectiveness of the asphalt blend, and extending its shelf life, while reducing the amount of materials needed, thus being cost-effective and suitable for patching applications.
Implementation Method 1
The asphalt mix has low viscosity at ambient temperatures and is workable at ambient temperatures
Implementation Method 2
An asphalt mix using pine extract and biodiesel as biodegradable solvents, combined with recycled asphalt products
Implementation Method 3
with a method involving extended dry mixing to coat aggregates with asphalt cement
Data Source
AI summary
A method of manufacturing an asphalt mix comprising: heating aggregate; introducing RAP to the aggregate; dry mixing the RAP and aggregate; forming a coating of AC on all aggregate during the step of dry mixing by extending the length in time of the dry mixing step; separately blending AC, biodegradable solvents, and anti-stripping agent to produce a blend; and wet mixing the blend into the RAP and aggregate mix. The biodegradable solvents are capable of making the asphalt mix workable at ambient temperatures and comprise pine extract and biodiesel. The length of the dry mixing is extended to at least about 35 seconds. The aggregate comprises coarse and fine virgin aggregate. RAP is about 40% of the final product. The asphalt mix is stockpiled and bagged. The method further comprises manipulating encrusted material on the outside of the stockpiled cold asphalt mix back into the stockpile.