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摘要: 根据最大密度曲线理论, 采用轧制碎石料对n为0.35、0.40、0.45、0.50、0.55时的不同级配进行了马氏试验, 确定了沥青混合料最大密度时的n值, 考虑了Superpave关于禁区和控制点的建议, 以及生产实践中允许出现的各档集料用量的变动幅度, 确定了沥青上、中、下面层混合料的级配范围。利用贝雷法的验算和工程实践的检验证明采用所提出的级配范围拌制的沥青混合料基本上达到嵌挤-密实的状态, 既可大大减少渗水, 又具有较高的抗车辙能力。
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关键词:
- 道路工程 /
- Superpave级配范围 /
- 贝雷法
Abstract: Based on the maximal density graph theory, Marshall experiments were done with crushed stone when the values of n equal to 0.35, 0.40, 0.45, 0.50 and 0.55. The values of n were ascertained when the asphalt mix density was maximal.After a series of calculation and taking the Superpave's regulations about restricted zone and control points and the wave range of each sieve in engineering experience into account, the gradation scopes of super-layer, mid-layer and under- layer were put forward. The mix manufactured within these gradation scopes is proved having scarf joint-compact state to both reduce penetration, and have good anti-rutting performance by engineering experience and Bailey's method.-
Key words:
- road engineering /
- gradation scope of Superpave /
- Bailey's method
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表 1 级配组成数据
Table 1. Datas of different aggregate gradations
表 2 马氏试验结果
Table 2. Results of Marshall test
表 3 集料级配的禁区边界
Table 3. Boundary of restricted zone of aggregate gradation
禁区内筛孔尺寸/mm 最大标称尺寸(mm) 时禁区边界(最小/最大) 通过率/% 37.5 25.0 19.0 12.5 9.5 4.75 34.7/34.7 39.5/39.5 — — — 2.36 23.3/27.3 26.8/30.8 34.6/34.6 37.6/37.6 47.2/47.2 1.18 15.5/21.5 18.1/24.1 22.3/30.0 25.6/31.6 31.6/37.6 0.60 11.7/15.7 13.6/17.6 16.7/20.7 19.1/21.1 23.5/27.5 0.30 10.0/10.0 11.4/11.4 13.7/13.7 15.5/15.5 18.7/18.7 表 4 集料级配的控制点
Table 4. Key points of aggregate gradation
筛孔/mm 下列最大标称尺寸(mm) 时控制点通过率/% 37.5 25.0 19.0 12.5 9.5 50.000 100 37.500 90~100 100 25.000 -90 90~100 100 19.000 -90 90~100 16.000 -90 100 12.500 90~100 100 9.500 -90 90~100 4.750 -90 2.360 15~41 19~45 23~49 28~58 32~67 0.075 0 (1) ~6 1~7 2~8 2~10 2~10 表 5 沥青混合料集料级配组成建议值
Table 5. Aggregate gradations suggested by author
表 6 各种级配关键筛孔通过率检验结果
Table 6. Validation of percents passing key sieve size of different gradations
级配类型 粗集料(CA比 > 0.4) 细集料 FAC < 0.5 FAF < 0.5 Sup-25 0.775 0.392 0.429 AC-25Ⅰ 0.568 0.595 0.520 AC-25Ⅱ 0.458 0.533 0.500 Sup-19 0.582 0.383 0.444 AC-20Ⅰ 0.368 0.563 0.556 Sup-12.5 0.280 0.490 0.517 AC-16Ⅰ 0.484 0.562 0.542 SAC-16 0.733 0.571 0.700 AK-16C (江苏) 0.667 0.489 0.591 注: 对于Sup-12.5考虑到构造深度的缘故, CA比调整为0.2~0.5之间。 表 7 表面层矿料级配与现行规范级配的比较
Table 7. Comparison of aggregate gradation of upper-layer pavement suggested by author with existing criterion's gradation
表 8 中面层矿料级配与现行规范级配的比较
Table 8. Comparison of aggregate gradation of mid-layer pavement suggested by author with existing criterion's gradation
表 9 下面层矿料级配与现行规范级配的比较
Table 9. Comparison of aggregate gradation of under-layer pavement suggested by author with existing criterion's gradation
表 10 Sup-25和AC-25Ⅰ的试验结果
Table 10. Test results of Sup-25 and AC-25Ⅰ
表 11 某Sup-25和AC-25Ⅰ动稳定度试验结果
Table 11. Results of rutting test of Sup-25 and AC-25Ⅰ
混合料类型 序号 动稳定度/次·mm-1 平均动稳定度/次·mm-1 Sup-25 1 2100 2267 2 2460 3 2240 AC-25-Ⅰ 1 1380 1370 2 1440 3 1290 表 12 Sup-19和AC-20Ⅰ的试验结果
Table 12. Test results of Sup-19 and AC-20Ⅰ
混合料类型 最佳含油量/% 空隙率/% VMA/% VFA/% 稳定度/kN 流值/0.1 mm 马歇尔模数/kN·mm-1 Sup-19 4.5 4.0 12.9 68.8 9.1 21.8 4.1 AC-20Ⅰ 4.6 3.7 14.1 74.1 9.2 28.3 3.2 表 13 某Sup-19和AC-20Ⅰ动稳定度试验结果
Table 13. Results of rutting test of Sup-19 and AC-20Ⅰ
混合料类型 序号 动稳定度/次·mm-1 平均动稳定度/次·mm-1 Sup-19 1 2100 2115 2 2520 3 1726 AC-20Ⅰ 1 700 863 2 1050 3 840 表 14 过去的试验结果
Table 14. Test results done past
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