浇注式沥青混凝土现状与发展

Review on Status and Development of Gussasphalt Concrete

为进一步确定浇注式沥青混凝土科学合理的性能评价指标及要求,全面梳理了国内外浇注式沥青混凝土相关规范,对比评价了不同规范中的技术指标要求及级配范围,系统地调查了大量实体工程及研究动态,厘定了浇注式沥青混凝土钢桥面铺装结构层组合、原材料类型和技术指标要求及级配类型,为浇注式沥青混凝土规范完善与质量控制奠定了基础。结果表明:推荐钢桥面铺装结构层组合为30~35mm GA-10+35~40mm SMA-10,GA基础沥青为SBS改性沥青+TLA(15%~30%),采用2%降粘剂;推荐性能评价指标要求范围为油石比7.9%~8.5%、流动度10~17s、贯入度1.4~2.5mm、贯入度增量不超过0.25mm、弯拉应变不小于7 000με、动稳定度不小于1 000次/mm(参考指标);疲劳性能试验以控制应变模式进行,结果以实测为准。

For the purpose of further determining the scientific and reasonable performance evaluation indexes of gussasphalt concrete, corresponding standards at home and abroad are combed comprehensively. Technical index requirements and gradation range of different standards are compared and evaluated. A large number of entity engineering and research trends are investigated systematically. The structure layer combination of steel deck pavement, raw materials, technical index requirements and gradation for gussasphalt concrete are determined, which can contributed to the improvement of standards and quality control of gussasphalt concrete. The results show that the combination of 30—35 mm GA-10 and 35—40 mm SMA-10 is recommended as structure layer of steel deck pavement. The combination of SBS modified asphalt and 15%—30%TLA is recommended as base asphalt of GA, with 2% viscosity reducer. The performance index requirements of asphalt-aggregate ratio within 7.9%—8.5%, fluidity within 10—17 s, penetration within 1.4—2.5 mm, penetration increment ≤0.25 mm and tensile strain ≥7 000με are proposed. At the same time, dynamic stability ≥1 000 times/mm is proposed as a reference index. Fatigue performance is tested under controlling strain and results are based on actual measurements.