基于MSCR试验的生物沥青高温性能评价

High-Temperature Performance Evaluation of Bio-Asphalt on the Basis of MSCR Test

通过高温分级试验和多应力蠕变恢复试验,研究了不同生物质重油掺量及温度下生物沥青的PG高温分级、不可恢复蠕变柔量、蠕变恢复率和应力敏感性,对比分析了基于AASHTO MP 19标准的生物沥青高温性能分级,并采用车辙试验验证了生物沥青混合料的高温性能.结果表明:综合等车辙因子临界温度对生物沥青的原样沥青的等级划分效果明显;生物沥青的恢复率较基质沥青和S100沥青大,蠕变柔量较基质沥青和S100沥青小;生物沥青的不可恢复蠕变柔量和蠕变恢复率应力敏感性随生物质重油掺量的变化不呈现明显规律,但应力敏感性随温度的升高而增大;64℃可作为低掺量生物沥青高温分级的基准温度.

The PG high-temperature classification,unrecoverable creep compliance,creep recovery rate and stress sensitivity of the bio-asphalt with different bio-oil dosages and temperatures were investigated by a high-temperature classification test and a multiple stress creep recovery test（ MSCR）,and the classification of the high-temperature performance of the bio-asphalt on the basis of the AASHTO MP 19 standard was analyzed. Then,the high-temperature performance of bio-asphalt mixtures was verified by a rutting test. The results show that（ 1） the critical temperature of integrated asphalt rutting factor produces a significant effect on the classification of origin bio-asphalt;（ 2） as compared with the matrix asphalt and S100 asphalt,the bio-asphalt achieves a higher recovery rate but with a smaller creep compliance;（ 3） the unrecoverable creep compliance and the stress sensitivity of the creep recovery rate show no obvious rule with the change of the bio-oil dosage,while the stress sensitivity of the bio-asphalt increases with the rise of temperature; and（ 4） 64 ℃ can be used as the reference temperature for high-temperature classification of low-dosage bio-asphalt.