-
摘要: 为探究微胶囊沥青自愈合行为及其影响因素，采用原位聚合法制备微胶囊，以宏观试验与微观试验相结合的方法，从微胶囊的应力控释、毛细作用与扩散行为三方面揭示其自愈合行为的微观机理；进行了微胶囊沥青的拉拔-愈合-拉拔试验，采用自愈率(试件愈合后拉拔强度与初始拉拔强度之比)作为评价指标，考察了微胶囊掺量和愈合时间对微胶囊沥青自愈率的影响规律；进行了微胶囊沥青的动态剪切试验，对比疲劳试验前后微胶囊沥青的微观形态，考察微胶囊的应力控释特性；借助荧光显微镜，可视化了芯材在微裂缝中的横、纵向毛细作用与在沥青中的扩散过程；借助显微图像软件中的实时录像功能，观测微胶囊沥青微裂缝的愈合过程；采用红外光谱测试微胶囊芯材和拉拔-愈合-拉拔试验前后微胶囊沥青的官能团，考察芯材在沥青中的释放行为。分析结果表明：微胶囊掺量从0提升至8%时，自愈率从16.70%提高至48.92%，表明微胶囊沥青的自愈率随着微胶囊掺量的增加而逐渐增大，当微胶囊掺量为4%时，愈合120 min的自愈率是愈合10 min的1.85倍，表明微胶囊沥青的自愈率随着沥青愈合时间的延长而逐渐增大，这说明提高荷载休息期和微胶囊掺量对增强微胶囊沥青自愈合性能具有积极作用；微胶囊沥青的微观自愈合机理为，微裂缝尖端应力刺破微胶囊的囊壁而释放囊芯愈合剂，芯材在毛细管作用力的驱动下流动、扩散，并与附近的沥青接触、浸湿，从而达到修复沥青微裂缝的目的。Abstract: In order to explore the self-healing behavior of microencapsulated asphalt and its influencing factors, microcapsules were prepared by in-situ polymerization, and the micro-mechanism of self-healing behavior of microcapsules was revealed from three aspects: stress-controlled release, capillary action, and diffusion behavior by combining macro-test and micro-test. The pull-heal-pull test of microencapsulated asphalt was carried out, the self-healing rate (the ratio of pulling strength after healing to initial pulling strength) was used as the evaluation index, and the effect rules of microcapsule content and healing time on the self-healing rate were investigated. The dynamic shear rheological test of microencapsulated asphalt was carried out, and the stress-controlled release characteristics of microencapsulated asphalt were investigated by comparing the microstructures of microencapsulated asphalt before and after the fatigue test. The horizontal and vertical capillary action of core material in micro-cracks and the diffusion process of core material in microencapsulated asphalt were visualized by the fluorescence microscope. The healing process of micro-cracks in microencapsulated asphalt was observed by the real-time video recording function in microscopic image software. The release behavior of core material in microencapsulated asphalt was investigated by testing the functional groups of microcapsule core material and microencapsulated asphalt before and after the pull-heal-pull test based on infrared spectrum. Analysis results show that the self-healing rate increases from 16.70% to 48.92% when the microcapsule dosage increases from 0 to 8%, indicating that the self-healing rate of microencapsulated asphalt increases gradually with the increase of microcapsule dosage. When the microcapsule dosage is 4%, the self-healing rate in 120 min is 1.85 times that in 10 min, indicating that the self-healing rate of microencapsulated asphalt increases gradually with the extension of asphalt healing time. Obviously, increasing the load rest period and microcapsule dosage has a positive effect on enhancing the self-healing performance of microencapsulated asphalt. The microscopic self-healing mechanism of microencapsulated asphalt is that the microcapsule shell is punctured under the stress at the tip of the microcrack, then the core healing agent is released, so that the core material flows and diffuses under the drive of capillary force, contacts with nearby asphalt and is soaked, so as to achieve the purpose of repairing asphalt microcracks.
-
图 1 微胶囊原位聚合法制备流程
Figure 1. Preparation process of microcapsule by in-situ polymerization
图 4 自愈率与微胶囊掺量的关系
Figure 4. Relationship between self-healing rate and microcapsule dosage
图 6 拉拔后微胶囊沥青断面的FM图像
Figure 6. FM images of microencapsulated asphalt section after pulling
图 7 DSR前后微胶囊沥青样的FM图像
Figure 7. FM images of microencapsulated asphalt before and after DSR
图 9 微胶囊芯材在微裂缝中的横向毛细流动行为
Figure 9. Transverse capillary flow behavior of microcapsule core material in microcrack
图 10 微胶囊芯材在微裂缝中的纵向毛细流动行为
Figure 10. Longitudinal capillary flow behavior of microcapsule core material in microcracks
图 11 微胶囊芯材在沥青中扩散的FM图像
Figure 11. FM images of diffusion of microcapsule core material in microencapsulated asphalt
图 12 芯材与微胶囊沥青样品的红外光谱
Figure 12. Infrared spectra of core material and microencapsulated asphalt samples
表 1 沥青试验结果
Table 1. Test result of asphalt
25 ℃针入度/0.1 mm 软化点/℃ 10 ℃延度/cm 60 ℃动力黏度/(Pa·s) 68.1 47.5 68 210 
下载: 导出CSV
表 2 不同微胶囊掺量和愈合时间下的自愈率
Table 2. Self-healing rates under different microcapsule dosages and healing times
微胶囊掺量/% 不同愈合时间(min)下的自愈率/% 10 30 60 120 0 8.74 12.91 19.66 25.50 2 11.42 14.68 23.57 31.63 4 18.13 27.46 40.28 51.59 6 20.97 34.14 51.88 59.29 8 22.57 37.89 60.71 74.52
下载: 导出CSV
-
[1] MICAELO R, FREIRE A C, PEREIRA G. Asphalt self-healing with encapsulated rejuvenators: effect of calcium-alginate capsules on stiffness, fatigue and rutting properties[J]. Materials and Structures, 2020, 53(1): 20. doi: 10.1617/s11527-020-1453-7 [2] CHEN An-qi, ZHAO Yong-li, LI Peng-bo, et al. Crack propagation prediction of asphalt pavement after maintenance as a function of initial cracks distribution[J]. Construction and Building Materials, 2020, 231: 117157. doi: 10.1016/j.conbuildmat.2019.117157 [3] 何亮, 李冠男, 熊汉江, 等. 钢砂SBS改性沥青混凝土裂纹的感应加热自修复性能[J]. 交通运输工程学报, 2018, 18(3): 11-18. doi: 10.3969/j.issn.1671-1637.2018.03.003HE Liang, LI Guan-nan, XIONG Han-jiang, et al. Induction heating activated self-healing of cracks in SBS modified asphalt concrete adding steel grits[J]. Journal of Traffic and Transportation Engineering, 2018, 18(3): 11-18. (in Chinese) doi: 10.3969/j.issn.1671-1637.2018.03.003 [4] NORAMBUENA-CONTRERAS J, YALCIN E, GARCIA A, et al. Effect of mixing and ageing on the mechanical and self-healing properties of asphalt mixtures containing polymeric capsules[J]. Construction and Building Materials, 2018, 175: 254-266. doi: 10.1016/j.conbuildmat.2018.04.153 [5] LI Jia, JI Xiao-ping, TANG Zhen-nong, et al. Preparation and evaluation of self-healing microcapsules for asphalt based on response surface optimization[J]. Journal of Applied Polymer Science, 2022, 139(1): 51430. doi: 10.1002/app.51430 [6] GARCIA A, JELFS J, AUSTIN C J. Internal asphalt mixture rejuvenation using capsules[J]. Construction and Building Materials, 2015, 101: 309-316. doi: 10.1016/j.conbuildmat.2015.10.062 [7] 纪小平, 杨自广, 周泽洪, 等. 密级配沥青混合料自愈性能的评价方法[J]. 中国公路学报, 2018, 31(11): 51-57. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGGL201811007.htmJI Xiao-ping, YANG Zi-guang, ZHOU Ze-hong, et al. Evaluation method for self-healing property of dense-graded asphalt mixture[J]. China Journal of Highway and Transport, 2018, 31(11): 51-57. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-ZGGL201811007.htm [8] NORAMBUENA-CONTRERAS J, LIU Quan-tao, ZHANG Lei, et al. Influence of encapsulated sunflower oil on the mechanical and self-healing properties of dense-graded asphalt mixtures[J]. Materials and Structures, 2019, 52(4): 78. doi: 10.1617/s11527-019-1376-3 [9] JI Xiao-ping, LI Jia, HUA Wen-long, et al. Preparation and performance of microcapsules for asphalt pavements using interfacial polymerization[J]. Construction and Building Materials, 2021, 289: 123179. doi: 10.1016/j.conbuildmat.2021.123179 [10] SUN Da-quan, LU Tong, ZHU Xing-yi, et al. Optimization of synthesis technology to improve the design of asphalt self- healing microcapsules[J]. Construction and Building Materials, 2018, 175: 88-103. doi: 10.1016/j.conbuildmat.2018.04.162 [11] TABAKOVIĆ A, BRAAK D, VAN GERWEN M, et al. The compartmented alginate fibres optimisation for bitumen rejuvenator encapsulation[J]. Journal of Traffic and Transportation Engineering (English Edition), 2017, 4(4): 347-359. doi: 10.1016/j.jtte.2017.01.004 [12] GARCÍA Á, SCHLANGEN E, VAN DE VEN M F C. How to make capsules containing rejuvenators for their use in asphalt concrete[J]. Journal of Wuhan University of Technology, 2010, 32(17): 18-21, 34. [13] 罗蓉, 石晨光, 冯光乐. 沥青自愈合性能评价指标修正及应用[J]. 中国公路学报, 2019, 32(11): 103-108. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGGL201911010.htmLUO Rong, SHI Chen-guang, FENG Guang-le. Correction and application of self-healing performance index of asphalt binder[J]. China Journal of Highway and Transport, 2019, 32(11): 103-108. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-ZGGL201911010.htm [14] XUE Bin, WANG Hui-feng, PEI Jian-zhong, et al. Study on self-healing microcapsule containing rejuvenator for asphalt[J]. Construction and Building Materials, 2017, 135: 641-649. doi: 10.1016/j.conbuildmat.2016.12.165 [15] NORAMBUENA-CONTRERAS J, YALCIN E, HUDSON-GRIFFITHS R, et al. Mechanical and self-healing properties of stone mastic asphalt containing encapsulated rejuvenators[J]. Journal of Materials in Civil Engineering, 2019, 31(5): 04019052. doi: 10.1061/(ASCE)MT.1943-5533.0002687 [16] 周璐, 黄卫东, 吕泉. 干湿条件下沥青自愈合性能评价与机理分析[J]. 建筑材料学报, 2021, 24(1): 137-145. https://www.cnki.com.cn/Article/CJFDTOTAL-JZCX202101020.htmZHOU Lu, HUANG Wei-dong, LYU Quan. Evaluation and mechanism analysis of asphalt self-healing property under dry and wet conditions[J]. Journal of Building Materials, 2021, 24(1): 137-145. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-JZCX202101020.htm [17] SU Jun-feng, WANG Li-qing, XIE Xin-ming, et al. Understanding the final surface state of self-healing microcapsules containing rejuvenator in bituminous binder of asphalt[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2021, 615: 126287. doi: 10.1016/j.colsurfa.2021.126287 [18] SHU Be-nan, WU Shao-peng, DONG Li-jie, et al. Microfluidic synthesis of polymeric fibers containing rejuvenating agent for asphalt self-healing[J]. Construction and Building Materials, 2019, 219: 176-183. doi: 10.1016/j.conbuildmat.2019.05.178 [19] SUN Da-quan, SUN Guo-qiang, ZHU Xing-yi, et al. Identification of wetting and molecular diffusion stages during self-healing process of asphalt binder via fluorescence microscope[J]. Construction and Building Materials, 2017, 132: 230-239. doi: 10.1016/j.conbuildmat.2016.11.137 [20] HOU Yue, WANG Lin-bing, PAULI T, et al. Investigation of the asphalt self-healing mechanism using a phase-field model[J]. Journal of Materials in Civil Engineering, 2015, 27(3): 04014118. doi: 10.1061/(ASCE)MT.1943-5533.0001047 [21] SUN Da-quan, SUN Guo-qiang, ZHU Xing-yi, et al. A comprehensive review on self-healing of asphalt materials: mechanism, model, characterization and enhancement[J]. Advances in Colloid and Interface Science, 2018, 256: 65-93. doi: 10.1016/j.cis.2018.05.003 [22] JI Xiao-ping, HAN Bo, HU Jian-ming, et al. Application of the discrete element method and CT scanning to investigate the compaction characteristics of the soil-rock mixture in the subgrade[J]. Road Materials and Pavement Design, 2022, 23(2): 397-413. doi: 10.1080/14680629.2020.1826350 [23] 汪海年, 丁鹤洋, 冯珀楠, 等. 沥青混合料分子模拟技术综述[J]. 交通运输工程学报, 2020, 20(2): 1-14. doi: 10.19818/j.cnki.1671-1637.2020.02.001WANG Hai-nian, DING He-yang, FENG Po-nan, et al. Advances on molecular simulation technique in asphalt mixture[J]. Journal of Traffic and Transportation Engineering, 2020, 20(2): 1-14. (in Chinese) doi: 10.19818/j.cnki.1671-1637.2020.02.001 [24] 谭忆秋, 李冠男, 单丽岩, 等. 沥青微观结构组成研究进展[J]. 交通运输工程学报, 2020, 20(6): 1-17. doi: 10.19818/j.cnki.1671-1637.2020.06.001TAN Yi-qiu, LI Guan-nan, SHAN Li-yan, et al. Research progress of bitumen microstructures and components[J]. Journal of Traffic and Transportation Engineering, 2020, 20(6): 1-17. (in Chinese) doi: 10.19818/j.cnki.1671-1637.2020.06.001 [25] SUN Da-quan, LIN Tian-ban, ZHU Xing-yi, et al. Calculation and evaluation of activation energy as a self-healing indication of asphalt mastic[J]. Construction and Building Materials, 2015, 95: 431-436. doi: 10.1016/j.conbuildmat.2015.07.126 [26] SCHAPERY R A. On the mechanics of crack closing and bonding in linear viscoelastic media[J]. International Journal of Fracture, 1989, 39 (1): 163-189. [27] GARCÍA Á. Self-healing of open cracks in asphalt mastic[J]. Fuel, 2012, 93: 264-272. doi: 10.1016/j.fuel.2011.09.009 [28] 孙大权, 张立文, 梁果. 沥青混凝土疲劳损伤自愈合行为研究进展(1): 自愈合行为机理与表征方法[J]. 石油沥青, 2011, 25(5): 7-11. https://www.cnki.com.cn/Article/CJFDTOTAL-OILE201105004.htmSUN Da-quan, ZHANG Li-wen, LIANG Guo. Review on self-healing behavior of asphalt concrete (1) mechanism and characterization methods of self-healing behavior[J]. Petroleum Asphalt, 2011, 25(5): 7-11. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-OILE201105004.htm [29] LOEBER L, MULLER G, MOREL J, et al. Bitumen in colloid science: a chemical, structural and rheological approach[J]. Fuel, 1998, 77(13): 1443-1450. [30] HOU Yue, SUN Wen-juan, DAS P, et al. Coupled navier-stokes phase-field model to evaluate the microscopic phase separation in asphalt binder under thermal loading[J]. Journal of Materials in Civil Engineering, 2016, 28(10): 04016100. [31] QIU J, VAN DE VEN M F C, WU S P, et al. Investigating self healing behaviour of pure bitumen using Dynamic Shear Rheometer[J]. Fuel, 2011, 90(8): 2710-2720. [32] GASKIN J. On bitumen microstructure and the effects of crack healing[D]. Nottingham: The University of Nottingham, 2013. [33] LYU Quan, HUANG Wei-dong, XIAO Fei-peng. Laboratory evaluation of self-healing properties of various modified asphalt[J]. Construction and Building Materials, 2017, 136: 192-201. [34] TAN Yi-qiu, SHAN Li-yan, RICHARD KIM Y, et al. Healing characteristics of asphalt binder[J]. Construction and Building Materials, 2012, 27(1): 570-577. [35] SU Jun-feng, SCHLANGEN E, WANG Ying-yuan. Investigation the self-healing mechanism of aged bitumen using microcapsules containing rejuvenator[J]. Construction and Building Materials, 2015, 85: 49-56. [36] KARLSSON R, ISACSSON U. Laboratory studies of diffusion in bitumen using markers[J]. Journal of Materials Science, 2003, 38(13): 2835-2844. -
点击查看大图
图(12) / 表(2)
计量
- 文章访问数: 651
- HTML全文浏览量: 147
- PDF下载量: 106
- 被引次数: 0
