摘要：
Nanotechnology is an extension of sciences and technologies that deal with particles less than 100 nm. This paper reviews previous studies on how nanomaterials work and what their advantages are in subgrade and pavement engineering. In subgrade engineering, the nanomaterials particles can not only improve the physicochemical and mechanical properties of subgrade soils by filling the voids between soil particles but also promote hydration reaction between cement and ion exchange between soil particles. In pavement engineering, the water stability, rutting resistance, fatigue resistance and optical properties of flexible pavements are enhanced by adding nanomaterials into the asphalt mixture. Nanosilica enhances the interface between cement pastes and aggregates and promotes the pozzolanic reaction of concrete, thus, mechanical properties of concrete pavements are improved. Compared with traditional materials, nanomaterials play a promising role in subgrade and pavement engineering, benefitting from their environmental friendliness, lower environmental disturbance, better price/performance ratio and higher durability.
关键词：
Nanotalc;Disintegrated Carbonaceous Mudstone;Shear Strength;Cohesion;Angle of Internal Friction
摘要：
This work was aimed to improve the shear strength of disintegrated carbonaceous mudstone (DCM) with nanotalc (NT). A series of direct shear tests were carried out on the NT-modified DCM specimens to determine their shear strengths at various NT concentrations. Subsequently, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to reveal the underlying mechanism which the results showed that shear strength was first increased and then decreased with increasing certain NT concentration. Moreover, the increase in NT concentration also resulted in rise in cohesion and reduction in angle of internal friction. The optimum NT concentration for shear strength improvement of DCM is 4%. This improvement of shear strength is achieved because NT can fill the pores in DCM and its products can bind with particles. This results in formation of large aggregates owing to the small size, strong adsorption capacity and cation-exchange capacity.
期刊：
Transportation Safety and Environment,2020年2(1):3-17 ISSN：2631-6765
通讯作者：
Zeng, Ling(zl001@csust.edu.cn)
作者机构：
[Huanyi Zha; Ling Zeng] School of Civil Engineering, Changsha University of Science and Technology, Changsha Hunan, China;[Caiying Chen] School of Traffic and Transportation Engineering, Changsha University of Science and Technology, Changsha Hunan, China;[Chuankun Jia] College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha Hunan, China;[Hanbing Bian] Laboratory of Civil Engineering and Geo-Environment, Lille University, Ea 4515 LGCgE, Lille;F-59000, France
通讯机构：
[Ling Zeng] S;School of Civil Engineering, Changsha University of Science & Technology , Changsha Hunan, China
摘要：
Embankments filled with disintegrated carbonaceous mudstone (DCM) are prone to uneven settlements because of water-softening property and secondary disintegration of carbonaceous mud stone. To address this problem, nano-Al2O3 and cement were proposed in this study to improve the strength of DCM. Many nano-Al2O3-and cement-modified DCM (NACDCM) specimens with various nano-Al2O3 contents were prepared. Unconfined compression tests and triaxial compression tests were performed to examine the strengths of NACDCM under different conditions. Moreover, X-ray diffraction (XRD) analyses and scanning electron microscopy (SEM) observations were performed to reveal the microscopic mechanism for modification of the NACDCM. Macroscopic results showed that the unconfined compressive strength of NACDCM reached maximum when the nano-Al2O3 content was 0.2%. The cohesion showed positive correlation with nano-Al2O3 content while the angle of internal friction presented negative correlation with nano-Al2O3 content. Moreover, microscopic results indicated that nano-Al2O3 and cement improved the strength of NACDCM, mainly through cement hydration reaction pozzolanic reaction, ion exchange, gel effect and filling effect.
作者机构：
[付宏渊] School of Civil Engineering, Changsha University of Science & Technology, Changsha, 410114, China;Key Laboratory of Road Structure and Materials Transportation Industry, Changsha University of Science & Technology, Changsha, 410114, China;[蒋煌斌; 马吉倩] School of Traffic & Transportation Engineering, Changsha University of Science & Technology, Changsha, 410114, China;[欧健] Team 402, Hunan Provincial Bureau of Geology and Mineral Exploration and Development, Changsha, 410004, China;[邱祥] School of Civil Engineering, Changsha University of Science & Technology, Changsha, 410114, China<&wdkj&>Key Laboratory of Road Structure and Materials Transportation Industry, Changsha University of Science & Technology, Changsha, 410114, China
通讯机构：
School of Traffic & Transportation Engineering, Changsha University of Science & Technology, Changsha, China
作者机构：
[刘杰] Engineering Research Center of Catastrophic Prophylaxis and Treatment of Road & Traffic Safety of Ministry of Education, Changsha University of Science & Technology, Changsha;410114, China;[付宏渊; 史振宁] School of Traffic & Transportation Engineering, Changsha University of Science & Technology, Changsha;[Zeng, Ling; 张永杰] School of Civil Engineering, Changsha University of Science & Technology, Changsha;[刘杰] 410114, China <&wdkj&> School of Traffic & Transportation Engineering, Changsha University of Science & Technology, Changsha
通讯机构：
School of Civil Engineering, Changsha University of Science & Technology, Changsha, China
关键词：
土质边坡;降雨入渗;入渗深度;饱和区
摘要：
采用饱和-非饱和渗流有限元计算理论,建立一维、二维模型,对不同降雨强度、土质类型、表面吸力以及边坡坡度下的边坡降雨入渗深度和饱和区变化规律进行研究。研究结果表明:对于同种土质而言,初始表面吸力越小,降雨入渗深度越大,降雨入渗深度从大至小对应的土质依次为粉土、砂土和黏土;在降雨过程中,黏土在降雨入渗深度范围内均为饱和区域,而粉土则先在入渗深度范围内出现饱和区,随后饱和区域消散,砂土首先在降雨入渗范围内形成饱和区,随后饱和区下移形成悬挂式饱和区;边坡坡度越大,边坡底部的降雨入渗深度越大,粉土边坡受坡度影响更明显;在降雨作用下,当初始表面吸力为100 k Pa时,砂土边坡表面生成饱和区,随后饱和区扩大并下移;而当初始表面吸力为10 kPa时,降雨会导致粉土边坡地下水位上升。
作者机构：
[陈小薇; Zeng, Ling; 付宏渊; 陈少壮; 刘大顺] School of Civil Engineering, Changsha University of Science & Technology, Changsha;410114, China;[刘杰] School of Traffic & Transportation Engineering, Changsha University of Science & Technology, Changsha;[陈小薇; Zeng, Ling; 付宏渊; 刘杰; 陈少壮; 刘大顺] 410114, China
通讯机构：
School of Civil Engineering, Changsha University of Science & Technology, Changsha, China
作者机构：
[史振宁; 付宏渊; 马吉倩] School of Traffic and Transportation Engineering, Changsha University of Science &, Technology, Changsha, 410014, China;[Zeng, Ling; 王桂尧] School of Civil Engineering, Changsha University of Science &, Technology, Changsha, 410014, China;[马吉倩] Highway Administration Bureau of Hunan Province, Changsha, 410016, China
通讯机构：
School of Civil Engineering, Changsha University of Science & Technology, Changsha, China
作者机构：
[付宏渊; 马吉倩; 史振宁] School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha;Hunan;410114, China;[Zeng, Ling] School of Civil Engineering, Changsha University of Science & Technology, Changsha;[付宏渊; 马吉倩; 史振宁; Zeng, Ling] Hunan
作者机构：
[付宏渊; 邱祥; Zeng, Ling] Key Laboratory of Road Structure and Material of Ministry of Transport, Changsha University of Science &, Technology, Changsha, Hunan, 410114, China;[邱祥; 唐昊龙; 付宏渊] School of Traffic and Transportation Engineering, Changsha University of Science &, Technology, Changsha, Hunan, 410114, China;[李光裕; Zeng, Ling] School of Civil Engineering and Architecture, Changsha University of Science &, Technology, Changsha, Hunan, 410114, China
通讯机构：
Key Laboratory of Road Structure and Material of Ministry of Transport, Changsha University of Science & Technology, Changsha, Hunan, China
作者机构：
[王平] School of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China;[蒋朝晖] School of Chemistry and Biological Engineering, Changsha University of Science and Technology, Changsha, 410114, China;[何忠明; 付宏渊] School of Traffic and Transportation Engineering, Changsha University of Science and Technology, Changsha, 410114, China;[王琼] School of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China, School of Chemistry and Biological Engineering, Changsha University of Science and Technology, Changsha, 410114, China
通讯机构：
[Wang, P.] S;School of Environmental Science and Engineering, China
