Bitumen Chipping Runway Surface Texture Control
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Solution Overview
Problem
Existing methods for applying a top layer comprising bitumen and chippings onto a substrate fail to consistently achieve the desired physical properties, particularly in terms of texture depth and skid resistance, which are critical for runways and other high-traffic surfaces.
Innovation Solution
A method involving the application of a composition comprising bitumen and chippings, followed by heating, compacting, and cooling, with subsequent water-jetting to remove the bitumen skin and achieve the required texture depth, using adjustable parameters such as water pressure and speed to ensure reproducibility and effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a top layer comprising bitumen and chippings is applied onto a substrate using conventional methods, then the basic structure is formed, but the desired texture depth and skid resistance are not consistently achieved
Solution Approach 1:
The patent applies water-jetting as a preliminary treatment step before final compaction to remove the bitumen skin and expose the aggregate surface. This preliminary action ensures that the desired texture depth is achieved early in the process, allowing subsequent compaction to lock in the chippings without smothering them with excess bitumen, thereby consistently achieving the required texture depth and skid resistance
Solution Approach 2:
The patent controls the texture depth by adjusting water-jetting parameters (pressure, flow rate, nozzle distance) and compaction parameters (roller weight, number of passes). By systematically varying and optimizing these parameters, the method achieves consistent texture depth values and reliable physical properties across different applications and weather conditions
2Manufacturing precision
If water-jetting is used to remove bitumen skin and achieve texture depth, then skid resistance is enhanced, but the process complexity increases
Solution Approach 1:
The patent uses water-jetting (hydraulic method) to remove the bitumen skin from the surface of the compacted top layer. This hydraulic approach is more efficient and controllable than mechanical scraping or burning methods, allowing precise removal of bitumen to expose the aggregate surface without damaging the underlying structure, thereby enhancing skid resistance with a relatively simple hydraulic system
Solution Approach 2:
The patent incorporates measurement and control of texture depth during the water-jetting process to ensure the bitumen skin is removed to the appropriate extent. By monitoring texture depth and adjusting water-jetting parameters in real-time, the method achieves consistent skid resistance values while avoiding over- or under-treatment, thereby optimizing the process without excessive complexity
3Strength
If the top layer is compacted to achieve density, then structural integrity is improved, but the texture depth may be reduced due to bitumen skin formation
Solution Approach 1:
The patent extracts (removes) the bitumen skin from the surface of the compacted top layer through water-jetting. This extraction step separates the beneficial compacted structure (which provides structural integrity) from the harmful bitumen skin (which reduces texture depth and skid resistance). By removing only the surface bitumen layer and exposing the aggregate, the method preserves structural integrity while restoring adequate texture depth
Solution Approach 2:
The patent applies water-jetting selectively to the surface layer where bitumen skin formation occurs, without affecting the underlying compacted structure. This localized treatment removes bitumen skin only from the top surface (where texture depth is critical) while leaving the deeper compacted layers intact, thereby maintaining structural integrity while improving surface texture and skid resistance
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 method achieves a well-defined, reproducible, and structured top layer with enhanced skid resistance and texture depth, meeting the specific requirements for runways and other surfaces, even under varying weather conditions.
Implementation Method 1
water-jetting the cooled composition applied onto the substrate from iv), wherein step vi) is repeated if the texture depth measured in step v) is less than the reference value, wherein step vi) is terminated if the texture depth measured in step v) is equal to or greater than the reference value, wherein in step vi) the water pressure is in a range of 1500 bar - 3000 bar
Implementation Method 2
heating the composition from i)
Implementation Method 3
allowing the composition applied onto the substrate to cool
Data Source
AI summary
The present invention relates to a method for applying a top layer comprising bitumen and chippings onto a substrate. Furthermore, the present invention relates to a top layer comprising bitumen and chippings applied onto a substrate, and to a runway for aircraft which is provided with such a top layer.