High-modulus asphalt binder with low-temperature crack resistance
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Solution Overview
Problem
High-modulus asphalt mixtures used in China lack sufficient low-temperature crack resistance, limiting their application in cold regions such as the western and northern parts of the country, despite their high modulus and durability.
Innovation Solution
A high-modulus asphalt binder is developed, comprising a blend of natural and petroleum asphalt with a modifier, where the natural asphalt is crushed and mixed with molten petroleum asphalt, then ground at elevated temperatures to reduce large mineral particles and enhance low-temperature performance, using a polymer modifier like SBS or SBR to improve the binder's properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high-modulus asphalt mixture is used to achieve high modulus and durability, then load-carrying capacity and high-temperature deformation resistance are improved, but low-temperature crack resistance deteriorates
Solution Approach 1:
The patent uses a composite modification system combining three components: polymer modifier (SBS or SBR, 3-8 parts), ash content 30-60% natural asphalt (40-60 parts), and petroleum asphalt (32-57 parts). This multi-component composite approach creates synergistic effects where the polymer provides elasticity, natural asphalt provides adhesion and flexibility, and petroleum asphalt provides stiffness, collectively achieving both high modulus and low-temperature crack resistance
Solution Approach 2:
The patent optimizes multiple parameters including: polymer modifier content (3-8 parts per 100 parts asphalt), natural asphalt ash content (30-60%), natural asphalt to petroleum asphalt ratio (40-60:32-57), and processing temperature (160-180°C for grinding). These parameter optimizations ensure the binder achieves complex modulus ≥14000 MPa while maintaining low-temperature bending failure strain ≥2000 με
2Reliability
If natural asphalt with high ash content is used to improve adhesion and flexibility, then low-temperature performance is improved, but storage stability deteriorates due to mineral particle sedimentation
Solution Approach 1:
The patent uses polymer modifier (SBS or SBR) as an intermediary substance that adsorbs onto mineral particles from natural asphalt and forms a protective coating. This intermediary layer prevents mineral particle sedimentation and aggregation, maintaining storage stability while preserving the low-temperature performance benefits of high-ash natural asphalt
Solution Approach 2:
The patent creates local quality differentiation where polymer chains preferentially adsorb onto mineral particle surfaces, forming a protective interface layer. This localized modification at the particle-asphalt interface prevents sedimentation without compromising the bulk asphalt's low-temperature flexibility and adhesion properties
3Reliability
If polymer modifier content is increased to improve low-temperature crack resistance, then low-temperature performance is improved, but cost and viscosity increase
Solution Approach 1:
The patent merges three modification functions into a single integrated system: polymer modifier (3-8 parts) provides elasticity, natural asphalt (40-60 parts with 30-60% ash) provides adhesion and flexibility, and petroleum asphalt (32-57 parts) provides stiffness. This combined approach achieves low-temperature crack resistance with lower polymer content compared to conventional single-modifier systems
Solution Approach 2:
The patent optimizes polymer modifier content to 3-8 parts per 100 parts asphalt, which is lower than conventional SBS-modified asphalt (typically 5-10 parts). This parameter optimization, combined with natural asphalt addition, achieves the required low-temperature bending failure strain ≥2000 με while controlling cost and viscosity
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 solution provides an asphalt binder with both high modulus and improved low-temperature performance, meeting or exceeding the required standards for low-temperature bending failure strain and ensuring stable storage and road performance in cold regions.
Implementation Method 1
The asphalt blend is ground when a temperature of the asphalt blend raises to 160° C. to 180° C.
Data Source
AI summary
A high-modulus asphalt binder of the present application includes 100 parts by weight of asphalt consisting of natural asphalt and petroleum asphalt in a weight ratio of 20-50:80-50, and 1-10 parts by weight of a modifier, wherein the ash content of the natural asphalt is as high as 60 wt % based on the weight of the natural asphalt, and trichloroethylene insoluble particles having a particle size of 10 microns or more in the asphalt binder are in a volume ratio of 5% or less.