基于MMLS1/3试验泡沫沥青冷再生混合料轮辙曲线特征及粗集料运动规律  

Curve Characteristicsof Foamed Cold Recycled Mixture Rutting and Law of Coarse Aggregate Movement Based on MMLS1/3 Test

作　　者：詹国良 ZHAN Guo-liang(China Tunnel Construction Group Co. Ltd. GUANG DONG , Guangzhou 510335,China)

机构地区：[1]广东华隧建设集团股份有限公司

出　　处：《公路》2018年第4期228-237,共10页Highway

基　　金：国家自然基金项目,项目编号51409352

摘　　要：对泡沫沥青冷再生混合料进行常温条件下的MMLS1/3加速加载试验,探讨了泡沫沥青冷再生混合料车辙深度、变形速率及横断面轮辙曲线特征,分析给出了泡沫沥青冷再生混合料车辙深度随加载次数的变化趋势;对不同加载次数下轮迹处MMLS1/3试件进行X-ray无损扫描,分析了不同加载次数下泡沫沥青冷再生混合料的轮辙曲线特征及粗集料运动规律。结果表明,对于未掺加水泥的泡沫沥青冷再生混合料试件,轮迹处车辙沿横断面分布呈U形,掺加1%~2.5%水泥后泡沫沥青冷再生混合料试件横断面车辙分布呈W形,可采用RDD=A×NB预估不同加载次数（N）下的车辙深度（RDD）发展规律;MMLS1/3加载试验过程中泡沫沥青冷再生混合料车辙发展规律可分为3个阶段,即压密阶段、蠕变稳定阶段、剪切破坏阶段;重复疲劳荷载作用下轮辙变形主要来源于泡沫沥青砂浆压密变形、集料受荷载作用产生的竖向位移及粗集料自身由不稳定状态转变为“平躺”状态所发生的水平转动位移,粗集料取向角随加载次数增大呈指数函数关系减小。MMLS1/3试验过程中压密变形主要是由车辆荷载的进一步压实作用引起,主要造成泡沫沥青冷再生混合料中大孔数量减少,微孔数量增多;试件破坏阶段泡沫沥青冷再生混合料内部微孔数量减小,大于1mm3空隙数量增多。掺加适量水泥可约束泡沫沥青冷再生混合料集料产生水平转动位移,具有维持加载过程中泡沫沥青冷再生混合料空隙形状和孔级配变化不大的作用。The MMLS1/3 accelerated loading test of foam asphalt cold regenerated mixture is studied under normal temperature conditions. The characteristics of rutting depth, deformation rate and crosssection rutting curve of cold asphalt mixture are discussed. The MMLS1/3 specimensare carried out X-ray nondestructive scanning at different wheelsunder different loading times. The characteristics of the rut eurvefor foam asphalt cold regeneration and coarse aggregate movement rules under different loading times are analyzed. The results show that the rutting of the trough is U-shaped along the cross section for mixture specimen without cement, and after adding 1 % -2.5% cement to the foam asphalt cold recycled mixture specimen, the rut distribution presents a W-shape. The formula RDD=A ＊NB can be used to estimate the development rules of rut development depth （RDD） under different loading times N. The rutting development rules of foam asphalt cold recycled mixture during MMLS1/3 loading test can be divided into three-stage： the compaction stage, the creep stabilization stage and the shear failure stage. The torsional deformation under the repeated fatigue load mainly comes fromthe compression deformation of the foam asphalt mortar and the vertical displacement of aggregate due to loading and the horizontal rotation of the coarse aggregatecaused by changing from the unstable state to the ＂lie-down＂ state, and the orientation angle of the coarse aggregate decreases exponentially with the increase of the loading times. The compaction deformation of MMLS1/3 during the test is mainly caused by the step-by-step compaction of the vehicle load, which mainly results in the reduction of the number of large voids in the foamed asphalt cold recycled mixture, the increase of the number of micro-voids, and at the failure stage of the foam asphalt cold regenerated mixture, decrease of the number of internal micro-voids, and increase of void quantity more than 1 mma. Proper addition of cement can restrain foam asphalt cold recyc

关 键 词：道路工程 泡沫沥青冷再生 加速加载试验 轮辙曲线特征 粗集料运动规律 空隙演变分析 

分 类 号：U416.26[交通运输工程—道路与铁道工程]