Rubber-Modified Bitumen Composition With Controlled CR Phase Balance
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Solution Overview
Problem
Existing bitumen compositions face challenges in effectively incorporating high amounts of Crumb Rubber (CR) due to phase separation and contrasting mechanical properties, leading to issues such as high viscosity, low workability, and reduced adhesive strength, which limits CR content to 22% by weight, and current fabrication methods fail to balance UDCR and FDCR phases for stable performance.
Innovation Solution
A three-stage fabrication process is employed to produce High Content Rubber Modified Bitumen (HCRMB) by fully dissolving and controlling the UDCR and FDCR phases separately, allowing up to 50% CR content, using polyisoprene, recycled oil, and additives like resin and cross-linkers in high shear mixers to achieve stable and durable bitumen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high amounts of Crumb Rubber (CR) are incorporated into bitumen, then the performance and durability of bitumen are improved, but phase separation and contrasting mechanical properties occur, leading to high viscosity and low workability
Solution Approach 1:
The invention segments the CR incorporation process into two distinct stages: first dissolving CR to form FDCR phase, then adding more CR to form UDCR phase. This segmentation allows control over the proportion of dissolved and undissolved phases, optimizing both durability enhancement and workability maintenance.
Solution Approach 2:
The invention changes the parameters of CR incorporation by controlling the proportion of FDCR and UDCR phases through a two-stage process. By adjusting the amount of CR added in each stage and the dissolution conditions, the viscosity and mechanical properties can be optimized to balance durability improvement with workability.
2Reliability
If high amounts of Crumb Rubber (CR) are incorporated into bitumen, then the performance and durability of bitumen are improved, but adhesive strength is reduced
Solution Approach 1:
The invention optimizes the proportion of FDCR and UDCR phases to balance adhesive strength with durability. The FDCR phase enhances adhesive properties while the UDCR phase provides structural reinforcement, and their optimized combination maintains both adhesive strength and durability.
Solution Approach 2:
The invention creates a composite bitumen system containing both FDCR and UDCR phases with different functions. The FDCR phase provides adhesive properties and flexibility, while the UDCR phase provides structural strength and durability, creating a synergistic composite material.
3Ease of operation
If Crumb Rubber (CR) is fully dissolved in bitumen, then workability and compatibility are improved, but viscosity decreases excessively and rutting resistance is reduced
Solution Approach 1:
The invention segments CR incorporation into two stages: first adding CR to form FDCR phase for improved workability, then adding additional CR to form UDCR phase for enhanced rutting resistance. This segmentation allows optimization of both workability and high-temperature performance.
Solution Approach 2:
The invention changes the proportion of dissolved and undissolved CR phases to optimize the balance between workability and rutting resistance. By controlling the FDCR/UDCR ratio, the bitumen maintains adequate viscosity for rutting resistance while preserving workability through the dissolved phase.
4Strength
If Crumb Rubber (CR) remains undissolved in bitumen, then rutting resistance is improved, but viscosity becomes excessively high and storage stability is reduced
Solution Approach 1:
The invention optimizes the proportion of FDCR and UDCR phases to balance rutting resistance with storage stability. The FDCR phase reduces viscosity and improves storage stability, while the UDCR phase provides rutting resistance, and their optimized combination achieves both goals.
Solution Approach 2:
The invention creates a composite system with FDCR and UDCR phases where the dissolved phase acts as a viscosity modifier and stability enhancer, while the undissolved phase provides structural reinforcement for rutting resistance, achieving a balanced performance profile.
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
HCRMB exhibits improved low and high-temperature performance, increased durability, and reduced rutting, while being cost-effective and easily implementable in existing production facilities, surpassing conventional bitumens in performance and durability.
Implementation Method 1
wherein 1 first weight part of the polymer is dissolved
Implementation Method 2
wherein 0,4-2,5 second weight parts of polymer is undissolved and incorporated in the bitumen-like material and wherein the second weight part of polymer is in the form of particles
Data Source
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AI summary
The present invention is in the field of a use of materials as fillers or components for bituminous compositions, in particular characterized by grain distribution. These materials are specially adapted to enhance the bitumen properties. In a first aspect the present invention relates to a bitumen composition, in a second aspect of producing such a composition, and in a third aspect to a road pavement, further comprising asphalt and such a bitumen composition.