| 摘要: |
| 基于电子计算机断层扫描（CT）技术和数字图像处理技术（DIP）,对比了扫描横断面上具有10~25倍等效半径的骨架紧密影响域分布特征,提出了水泥稳定碎石（CCRM）扫描横纵断面骨架指标,并将不同室内成型方法、不同振动时间的水泥稳定碎石的最大干密度、强度和骨架指标与室外芯样的相同指标进行对比.结果表明:具有20倍等效半径的粗颗粒影响域为构建骨架密实指标的覆盖质心域;可用骨架密实系数C和骨架稳定系数θ表征水泥稳定碎石骨架的密实性和稳定性;最大干密度、7d抗压强度、骨架指标C和θ均随振动时间的延长而增大,但增幅逐渐减小；静压成型方法不能与实际压实功相匹配,广东省高等级公路半刚性基层（常见级配和水泥掺量下）常见的施工工艺压实的路面基层与室内试验90s振动成型方式成型试件具有良好的匹配性.骨架指标θ和C与7d抗压强度之间有很强的相关性,说明水泥稳定碎石的微观骨架结构特性对其宏观力学性能具有显著的影响. |
| 关键词: 水泥稳定碎石 计算机断层扫描数字图像处理 骨架指标 振动成型时间 |
| DOI：103969/j.issn.1007 9629201904008 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（51378223）,广东省交通运输厅科技项目(2014 02 003,2016 02 003) |
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| Vibration Compaction Time of Cement Stabilized Crushed Rock Material Based on Micro skeleton Indices |
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LI Zhi1, LIU Jian1, JING Hongchen1, WU Wenliang1, SUN Yangyong2
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1.Shcool of Civil Engineering and Transportation, South China University and Technology, Guangzhou 510641, China;2.Guangdong Provincial Academy of Building Research Group, Guangzhou 510000, China
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| Abstract: |
| Based on computed tomography(CT) scanning and digital image processing(DIP) technique, distribution characteristics of different skeleton tightness ranges of circles whose radius is 1025 times larger than the equivalent radius of aggregates were compared. Skeleton indices of cement stabilized crushed rock material(CCRM) in scanning cross and longitudinal sections were proposed. Maximum dry density、compressive strength and these skeleton indices of laboratory produced CCRM by static pressure producing specimen method(SPSM) and vertical vibration compaction method with different vibration times and field drilled CCRM were compared. The results show the ranges of the twice equivalent radius is covering area of centroid for establishing skeleton indices; skeleton denseness index(C) and skeleton stability index(θ) can be used to capture density and stability of CCRM skeleton. All indices proposed get larger with compaction time increasing, but the increase amplification gets smaller. The work of SPSM indoors cannot match the outdoor compaction work; the work of 90s vibration compaction indoors matches common compaction work of constructing the semi rigid bases（common gradation and dosage）in Guangdong Province, China. There is a strong correlation between skeleton indices and the compressive strength after 7days, which indicates micro skeleton indices influences compressive strength significantly. |
| Key words: cement stabilized crushed rock material(CCRM) CT scanning and digital image processing skeleton indice vibration compaction time |
