Rubber Composite with Internal Oil Containment for Bitumen
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Solution Overview
Problem
Existing methods for producing rubber-modified bitumen composites are costly and complex, often requiring expensive equipment and resulting in poor homogeneity and stability due to issues like crumb rubber swelling and high oil distillate usage, leading to cracking and rutting in asphalt applications.
Innovation Solution
A rubber composite with a combination of powdered additives and a low content of heavy fraction oil distillate, where the oil is contained within the internal structure of the rubber, providing a non-sticky surface and improved mechanical properties, is manufactured using a process involving high shear rates and thermal shocks to control oil absorption and additive placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If crumb rubber is combined with bitumen binder using dry processing, then production costs are reduced and environmental pollution decreases, but the crumb rubber swells and absorbs the bitumen binder causing lack of homogeneity and poor compaction leading to cracking
Solution Approach 1:
The rubber granules are pre-treated with a chemical agent (such as zinc oxide or other activators) before being mixed with the bitumen binder. This preliminary chemical treatment modifies the rubber surface to control its interaction with the bitumen, preventing excessive absorption and swelling that would otherwise cause heterogeneity and compaction issues.
Solution Approach 2:
The patent modifies the chemical parameters of the rubber granules by introducing specific chemical agents that alter the rubber's affinity for bitumen. This parameter change controls the absorption rate and extent, ensuring homogeneous mixing while maintaining the cost benefits of dry processing.
2Reliability
If high amounts of heavy fraction oil distillate are used to activate rubber composite, then rubber modification effectiveness increases, but equipment complexity and production costs increase
Solution Approach 1:
The patent extracts the essential activation function from the complex heavy fraction oil distillate system and replaces it with simpler chemical agents applied directly to the rubber granules. This eliminates the need for complex heating and mixing equipment while maintaining rubber modification effectiveness.
Solution Approach 2:
The invention uses inexpensive chemical agents (such as zinc oxide powder or other simple additives) that can be applied in a simple mixing process, replacing the need for expensive heavy fraction oil distillate and complex processing equipment. The simple chemicals achieve the desired rubber activation at much lower cost and equipment complexity.
3Reliability
If crumb rubber is mixed with bitumen binder at high temperature for extended period, then rubber modification is achieved, but the process requires expensive on-site equipment and is not cost-effective
Solution Approach 1:
The rubber granules are pre-treated with chemical agents before mixing with bitumen, which enables the modification process to occur at lower temperatures and for shorter durations. This preliminary chemical preparation eliminates the need for expensive high-temperature processing equipment while achieving effective rubber modification.
Solution Approach 2:
The patent replaces the mechanical/thermal system (high-temperature mixing equipment) with a chemical system (reactive additives that work at lower temperatures). This substitution eliminates the need for expensive on-site heating and mixing equipment, making the process cost-effective.
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 resulting composite offers improved mechanical stability, reduced production costs, enhanced elasticity, and increased resistance to fatigue and rutting, while maintaining stability over time without being sticky, thus simplifying the manufacturing process and improving performance in paving applications.
Implementation Method 1
the oil is substantially contained within the internal structure of the rubber, and wherein the rubber's external surface is substantially oil-dry
Implementation Method 2
a process involving high shear rates and thermal shocks to control oil absorption and additive placement
Implementation Method 3
a process involving high shear rates and thermal shocks to control oil absorption and additive placement
Data Source
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AI summary
This disclosure provides a rubber composite for use in a variety of applications, and processes for its preparation.