Study On The Compaction Technology Of Double-drum Vibratory Roller For Asphalt Pavement

The double drum vibratory rollers are major equipment in compaction engineering, so thecompaction quality is an important factor affecting the quality and life of pavement. Thedetailed and systemic research of compaction parameters and technology is scarce, andmanufacturers of rollers cannot provide appropriate parameters for particular structure andmaterials. In consideration of this situation, a study method about compaction technology wasdiscussed, which can provide reference to choose compaction technology.Firstly, a theoretical analysis about compaction pass, vibratory model, and compactionparameters was made. The following conclusions were drawn: the compaction pass can beestimated through energy equivalent method, and better compaction quality will be achievedwhen adopting vibratory compaction model in the forward direction. Two concepts ofeffective contact width and overlap value are raised through analyzing force and shape ofcontact area between drum and material. A formula about speed, frequency, effective contactwidth, overlap value was put forward.Secondly, a homebred roller and AC-13material were set as research object. Effectivecontact width was calculated through measuring lift thickness after each pass. The resultshows that: effective contact width increase as amplitude and lift thickness increased; it wasthe biggest at the beginning of compaction, and decreased rapidly as the compaction progressgoing-on. And a mathematical model was presented through analyzing the change of liftthickness, it reflects affection of material and compaction pass in compaction process.Finally, the best compaction technology was researched in a highway construction site. Thebest compaction pass was got through compaction test of material, the compaction model andparameters were set through contrast test. Through analyzing variability of compactness, thereasonable rang and best value of compaction speed were determined.The highlight of this paper is the way to determine the relationship between compactionfrequency and speed through effective contact width.