Design method of warm mix asphalt based on Marshall test under variable temperatures and compaction times
-
摘要: 为了建立温拌沥青混合料组成设计方法, 在不同温度和击实次数下进行了AC-13C温拌沥青混合料的马歇尔击实试验, 分析了温拌沥青混合料体积特性。分析结果表明: 随着击实温度的降低和击实次数的减少, 温拌沥青混合料的空隙率和矿料间隙率增大, 沥青饱和度降低; 与热拌沥青混合料相比, 温拌沥青混合料中沥青被集料吸收的含量(质量分数)、有效沥青含量和沥青膜厚度变化很小, 并确定了AC-13C温拌沥青混合料的最佳沥青用量为4.7%。根据体积特性确定了温拌沥青混合料的成型温度, 与热拌沥青混合料相比, 温拌基质沥青混合料的成型温度降低约为10℃~20℃, 温拌SBS改性沥青混合料的成型温度降低约为10℃; 温拌沥青混合料具有更好的可压实性, 与热拌沥青混合料相比, 温拌基质沥青混合料击实次数降低约为20%, 温拌SBS改性沥青混合料的击实次数降低约为10%。Abstract: In order to establish the mixture design method for warm mix asphalt (WMA), Marshall test was conducted under variable temperatures and compaction times to prepare AC-13C WMA specimens, and the volume characteristics of WMA specimens were researched. Analysis result indicates that the air void volume (VV) and the percent voids in mineral aggregate (VMA) increase with the decrease of compaction temperatures and compaction times, but the percent voids in mineral aggregate that are filled with asphalt (VFA) decrease. Compared with hot mix asphalt (HMA), the asphalt content absorbed by aggregates, the effective asphalt content (mass fraction) and the thickness of asphalt film in WMA differ a little, and the optimum asphalt content of AC-13C WMA is 4.7%. According to the volume characteristics, the compaction temperatures of WMAs are determined, and the compaction temperatures of WMAs with matrix asphalt and SBS modified asphalt decrease by about 10 ℃-20 ℃ and 10 ℃ respectively. WMA compactibility is better, and the compaction times of WMAs with matrix asphalt and SBS modified asphalt decrease by about 20% and 10% respectively.
-
Table 1. Gradation of AC-13C
Sieve size/mm 16 13.2 9.5 4.75 2.36 1.18 0.6 0.3 0.15 0.075 Passing rate/% 100.00 95.05 72.23 44.26 33.13 24.09 17.01 11.83 8.14 5.10 Table 2. Marshall test result of AC-13C HMAs
Type of asphalt Bulk specific gravity Measured theoretical maximum specific gravity Stability/kN Flow value/0.1 mm VV/% VMA/% VFA/% 70# 2.463 2.566 10.88 35.2 3.91 13.3 70.6 SBS 2.431 2.538 11.22 35.2 4.28 14.3 70.2 Table 3. Compaction temperatures and compaction times of WMA with matrix asphalt
Indices Specification requirement Compaction temperature/℃ Compaction times VV/% 4-6 110-145 75 or 55 VMA/% 14-16 105-135 75 or 55 VFA/% 65-75 125-145 75 or 55 Marshall stability/kN ≥8 100-145 75 or 55 Table 4. Compaction temperatures and compaction times for WMA with SBS modified asphalt
Indices Specification requirement Compaction temperature/℃ Compaction times VV/% 4-6 140-170 75 or 55 VMA/% 14-16 145-170 75 or 55 VFA/% 65-75 > 145 75 or 55 Marshall stability/kN ≥8 125-145 75 or 55 -
[1] ZHANG Jiu-peng, PEI Jian-zhong, XU Li, et al. Gyratory compaction characteristic of SBS warm mixed asphalt mixture[J]. Journal of Traffic and Transportation Engineering, 2011, 11 (1): 1-6. http://transport.chd.edu.cn/article/id/201101001 [2] LIU Wei, ZHANG Jie, LIN Ke, et al. Research on pavement performance of SMA-13 warm mix asphalt[J]. Road Machinery and Construction Mechanization, 2011, 28 (1): 63-65, 69. [3] PEI Jian-zhong, XING Xiang-yang. Study on construction technology of warm mix asphalt[J]. Road Machinery and Construction Mechanization, 2010, 27 (3): 41-44. [4] CHEN Guo-qiang, LIU Li-ping, GAO Xiao-fei, et al. Performance evaluation of asphalt mixture with sasobit[J]. Highway Engineering, 2009, 34 (6): 64-67. [5] QIN Yong-chun, HUANG Song-chang, XUJian, et al. Performance of SMA mixture based on evotherm-DAT warm mix asphalt technology[J]. Journal of Building Material, 2010, 13 (1): 32-35. [6] GUO Ping, QI Feng, MI Hai-chen. Road performance of warm mix asphalt mixture[J]. Journal of Chang'an University: Natural Science Edition, 2010, 30 (3): 10-13. [7] ZHOU Yan, CHEN Shuan-fa, ZHENG Mu-lian, et al. Research on mixing and compaction property of warm mix asphalt[J]. Journal of Wuhan University of Technology, 2010, 32 (1): 61-64. [8] XIAO Fei-peng, ZHAO Wen-bin, GANDHI T, et al. Influence of antistripping additives on moisture susceptibility of warm mix asphalt mixtures[J]. Journal of Materials in Civil Engineering, 2010, 22 (10): 1047-1055. doi: 10.1061/(ASCE)MT.1943-5533.0000111 [9] LI Zhen, XU Shi-fa, LUO Xiao-hui, et al. Evaluation of compaction characteristics of warm-recycled asphalt mixture[J]. Journal of Beijing University of Civil Engineering and Architecture, 2010, 26 (1): 14-19. [10] SUN Ji-shu, XIAO Tian, YANG Chuan-feng, et al. On properties of warm mix recycled asphalt mixture in highway[J]. Journal of Chongqing Jiaotong University: Natural Science, 2011, 30 (4): 250-253. [11] YU Jiang, SUN Ming, LI Lin-ping. Influence of mixing temperature on warm mix asphalt water stability[J]. Subgrade Engineering, 2011 (2): 10-13. [12] YANG Wen-feng, WU Shao-peng, MO Lian-tong, et al. Research on the effect of aggregate porosity on asphalt absorption and mixture's volume performance[J]. Journal of Wuhan University of Technology, 2003, 25 (12): 72-74. [13] ZHANG Hua, QIAN Jue-shi, WU Wen-jun. The influence of the filler-asphalt ratio on the high-and-low-temperature performance of gussasphalt mortar[J]. Journal of Chongqing University, 2009, 32 (6): 663-667. -