Study on low temperature performance and microstructure of rubber hot recycled mixture

作者：Wang Hai Nian^*; Zhang Chen; Fang Jun; Li Xiao Yan; You Zhan Ping

来源：Journal of Hunan University(Natural Sciences), 2014, 41(11): 123-128.

• CT scanning
• Freeze-thaw cycles
• Freezing-thawing
• Industrial computers
• Low temperature performance
• Low temperatures
• Recycled asphalt mixture
• Rubber asphalts

This paper took rubber recycled asphalt mixture as research objects, and the low temperature bending test was conducted on small specimen beams before and after freezing-thawing process separately. The low temperature performances of rubber hot recycled asphalt mixture with different rubber powder dosages (6.4%, 9.2% and 14.1%), rubber powder sizes (20 mesh, 40 mesh and 80 mesh) and RAP dosages (25%, 35% and 50%) were studied. The specimens were scanned before and after freezing-thawing process based on industrial computer tomography (CT) nondestructive testing, separately, and the quantitative analysis for the volume index of specimens was presented. The result shows that the low temperature performance of rubber hot recycled asphalt mixture with 25% RAP, 80 mesh rubber powder fineness and 9.2% rubber powder dosage after freezing-thawing process has the minimal decrease. Compared with hot recycled mixture with neat asphalt, the hot recycled asphalt mixture with crumb rubber asphalt has better durability and low temperature performance. By the comparison of different CT scanning results, the enclosed air void of specimens after freezing-thawing process increased by 20.3%, and the air void number has decreased by 13.8% in 0~25 mm3volume range and increased by 62.9% in 25~50 mm3volume range.

• 出版日期2014