期刊：
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY,2019年19(8):4465-4473 ISSN：1533-4880
通讯作者：
Shi, Xianming
作者机构：
[Gong, Jing; Li, Zhipeng; Zhang, Rongtang] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.;[Gong, Jing] Wuchang Univ Technol, Coll Urban Construct, Wuhan 430223, Hubei, Peoples R China.;[Li, Jianfen] Wuhan Polytech Univ, Sch Chem Engn & Environm, Wuhan 430023, Hubei, Peoples R China.;[Shi, Xianming] Washington State Univ, Dept Civil & Environm Engn, Lab Adv & Sustainable Cementitious Mat, Pullman, WA 99164 USA.
通讯机构：
[Shi, Xianming] W;Washington State Univ, Dept Civil & Environm Engn, Lab Adv & Sustainable Cementitious Mat, Pullman, WA 99164 USA.
关键词：
High Volume Fly Ash;Polyethylene Microfiber;Nano-Montmorillonite;Interface;EDX;Microhardness
摘要：
Foamed cement-based materials have attracted much attention as a new type of thermal insulation materials (TIMs) that may offer a sustainable solution to the built environments. This laboratory study explores the combined use of nano-montmorillonite and polyethylene microfiber in foamed paste with high volume fly ash (HVFA) binder. A total of 16 foamed HVFA paste mixtures were fabricated which consisted of 70% Class F fly ash, 30% Portland cement, 2% sodium alpha-olefin sulfonate, 0.38% Na(3)PO(4), and 2% nano-montmorillonite. The dosage and type of polyethylene microfibers (90 mum in diameter) were explored in the present study, with six dosages (0, 0.1%, 0.2%, 0.3%, 0.4%, 0.5% by volume) and three lengths (3 mm, 6 mm, and 9 mm) tested. Based on the experimental results, the highest 28-day rupture strength (1.51 MPa) was achieved with the use of 3-mm long PE microfibers at 0.4 vol.%. Synergistic utilization of nMMT and microfibers exhibited a great influence on the dry density and water absorption of the foamed paste. The SEM micrographs illustrated the multiple mechanisms by which the microfibers serve to reduce shrinkage-induced cracking of the foamed paste. Energy-dispersive X-ray spectroscopy was employed to obtain the contents of Ca, Si, Al, S and mole ratios of Ca/Si, Ca/(Si + Al), S/Ca, and Al/Si in the hardened pastes, which reveal the difference in hydration products near or away from the nMMT-pretreated polyethylene microfibers. The results of microhardness test were also used to elucidate such nano-/micro-synergistic effects, which improved the bonding between microfibers and foamed paste matrix. A mechanism was proposed to explain the role of various admixtures and the balanced performance of such inorganic TIMs.
期刊：
International Journal of Electrochemical Science,2018年13(1):498-513 ISSN：1452-3981
通讯作者：
Shi, Xianming
作者机构：
[Tong, Yangyang; Lit, Zhipeng; Gong, Jing; Shen, Zhang] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.;[Shi, Xianming] Washington State Univ, Dept Civil & Environm Engn, Lab Corros Sci & Electrochem Engn, POB 642910, Pullman, WA 99164 USA.
通讯机构：
[Shi, Xianming] W;Washington State Univ, Dept Civil & Environm Engn, Lab Corros Sci & Electrochem Engn, POB 642910, Pullman, WA 99164 USA.
关键词：
Electrical injection of corrosion inhibitor (EICI);Electrochemical chloride extraction (ECE);Finite element modeling;Rebar corrosion;Repair mortar
摘要：
Repair mortar is commonly used to rehabilitate reinforced concrete structures or components that exhibit a relatively high level of distresses. Yet, the repair mortar can be contaminated by salt from its service environment. This work employs a two-dimensional finite element model to investigate the non-stationary transport behavior of ionic species in salt-contaminated and water-saturated repair mortar under an externally applied electric field. The model was experimentally validated and then utilized to evaluate the effectiveness of electrochemical chloride extraction (ECE) with or without electrical injection of corrosion inhibitor (EICI). In the case study, both the ECE alone and the simultaneous ECE+EICI treatment was found effective in decontaminating the zone in front of the steel rebar. In both techniques, the magnitude of current density had a significant effect on removing chloride out of the mortar and increasing the pH of the pore solution near the rebar, whereas the treatment time did not have a significant effect under some scenarios. The injection of the organic corrosion inhibitor significantly slowed down the removal of chloride. Changes in the ionic distribution in the mortar were generally beneficial in reducing the corrosion risk of the steel rebar and thus extending the service life of the repair mortar.
摘要：
Graphene oxide (GO) is increasingly used in various applications, and the implications of this nano-sized material entering the natural environment are of great interest. GO is highly soluble in water, and its accumulation in soil could significantly alter the physical and mechanical properties of the soil. In this laboratory study, we mixed GO with a soil (clayey sand, SC) to systematically study the engineering properties and microstructure of the modified soil. The experimental results reveal that the physical and mechanical properties and microstructure of clayey sand can be significantly changed by the addition of a minute quantity of GO. The liquid limit and plasticity index of the soil steadily increased (up to a GO concentration of 0.08 wt%), whereas the plastic limit did not change significantly. The addition of GO (up to 0.08 wt%) into the soil generally decreased the soil's void ratio under a given hydrostatic consolidation pressure, while increasing its undrained shear strength. Such remarkable modifications of soil by minute amounts of GO can be attributed to the extremely high specific surface area of GO and its stable dispersion in water.
摘要：
Controlling the water content in soil is crucial for the load bearing capacity of soil. In the past few decades, electroosmosis has been proved to be a versatile strategy to consolidate soil in situ. However, the efficiency of this electrochemical technique needs to be further improved for practical application. This study was designed to test the hypothesis that the incorporation of nanoparticles (NPs) during electroosmosis can significantly facilitate the migration of water molecules under an external electric field and thus improve the physical properties of the treated soil. In addition, the number of anodes per cathode was explored as another method to improve the efficiency of electroosmosis in dewatering and strengthening soil. The results from the designed laboratory experiments confirmed the benefits of increasing the number of anodes or adding positively charged SiO2@Al2O3 core–shell NPs, in increasing the dewatering rate and improving the cohesion, internal friction angle, and microstructure of the treated soil (Lake Silt). The finite element method based simulation results agreed well with the experimental observations and suggested that the NPs can promote the water migration under an electric field.
关键词：
Alternating pulse electric field;Calcium chloride;Electroosmosis;Reinforcement;Scanning electron microscopy;Weak soil
摘要：
Electroosmosis has been extensively employed as an effective method for the dewatering treatment of soils and thus the reinforcement of weak soils. At the microscopic level, this treatment process is inherently complex due to in situ chemical and electrochemical reactions, migration of ions and particles, and the dependence of zeta potential of various particles on the local pH value in the soil. This complexity has hindered further understanding of mechanisms underlying the electroosmosis technology. Here, we design an external electric field in which alternating pulse wave potentials were partially used to adjust the pH value of the soil and manipulate the dynamics of in situ formed nanoparticles and their interconnectivity. The experimental results reveal that the in situ formation of Ca-rich particles, instead of water drainage, may serve as the main mechanism underlying the observed soil reinforcement when using calcium chloride as the treatment electrolyte. The interconnectivity of such particles may be the key for the shear strength improvement without significant settlement of the soil.
期刊：
International Journal of Electrochemical Science,2016年11(7):6023-6042 ISSN：1452-3981
通讯作者：
Li, Yongxin;Shi, Xianming
作者机构：
[Wang, Dongmei; Xiao, Xiaoqing; Li, Yongxin] Anhui Normal Univ, Coll Chem & Mat Sci, Wuhu 241000, Peoples R China.;[Shi, Xianming] Washington State Univ, Dept Civil & Environm Engn, POB 642910, Pullman, WA 99164 USA.;[Shi, Xianming] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Peoples R China.;[Li, Yongxin; Shi, Xianming; Jackson, Emily; Xie, Ning; Zhang, Yan; Fang, Yida] Montana State Univ, Western Transportat Inst, Bozeman, MT 59717 USA.
通讯机构：
[Li, Yongxin] A;[Shi, Xianming] W;[Li, YX; Shi, XM] M;Anhui Normal Univ, Coll Chem & Mat Sci, Wuhu 241000, Peoples R China.;Washington State Univ, Dept Civil & Environm Engn, POB 642910, Pullman, WA 99164 USA.
摘要：
A total of 12 multielectrode array sensors were utilized to assess the individual effectiveness of two corrosion inhibitors and one coating under cyclic deicer exposure conditions. There were four sensor groups, and each group consisted of nine-pin probes that were fabricated from 1008 carbon steel, 304 stainless steel, and 1100 aluminum, respectively. A total of two environmental exposure tests were conducted, in which 2.3% NaCl and 3.0% MgCl2 solutions were used as salt, respectively. The two tests each included eight environmental cycles and with 24h per cycle. For all the exposed sensors, the most severe corrosion occurred at the beginning of the humidity stage. For sensors in the control group, MgCl2 exhibited a corrosion attack throughout the exposure period, whereas NaCl only exhibited an apparent corrosion attack during the humidity stage. Both the sensor corrosion rates and mass loss results indicate that the inhibitors had a much greater effect for MgCl2 than for NaCl. Although the coating showed significant benefits in protecting the metallic substrates, the cyclic exposure to MgCl2 led to greater coating deterioration than did NaCl. For validation, impedance measurements were conducted on carbon steel panels subjected to similar exposures, and three-dimensional laser profilometer scans were performed to characterize their surface morphology after the exposures.
摘要：
Anti-Corrosion coatings are extensively applied in maintenance and vehicles used by transportation agencies, which have been used to protect a substrate by providing a barrier between the metal and its environment outside, especially in a chloride-laden environments. In order to provide adequate corrosion protection, the coatings must be uniform, well adhered, pore free and self-healing for applications where physical damage to the coating may occur. The aim of this review is to examine the state of the corrosion coatings for the protection of various metals/alloys commonly used in maintenance equipment and vehicles, and to identify cost effective, high-performance corrosion inhibitors that may contribute to the preservation of equipment assets. The focus is placed on the metallic corrosion induced or aggravated by chlorides at ambient temperature and pressure, and near neutral pH (6-8).
期刊：
Journal of Transportation Engineering,2014年140(11) ISSN：0733-947X
通讯作者：
Shi, Xianming
作者机构：
[Shi, Xianming] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Bozeman, MT 59717 USA.;[Akin, Michelle; Shi, Xianming; Fay, Laura; Veneziano, David A.] Montana State Univ, Western Transportat Inst, Bozeman, MT 59717 USA.;[Shi, Xianming] Montana State Univ, Dept Civil Engn, Bozeman, MT 59717 USA.;[Zhang, Yan; Jungwirth, Scott] Montana State Univ, Western Transportat Inst, Corros & Sustainable Infrastruct Lab, Bozeman, MT 59717 USA.;[Wright, Ron] Idaho Transportat Dept ITD, Boise, ID 83707 USA.
通讯机构：
[Shi, Xianming] W;Wuhan Polytech Univ, Sch Civil Engn & Architecture, POB 174250, Bozeman, MT 59717 USA.
摘要：
The use of chemicals and abrasives for highway winter maintenance operations is an essential strategy for ensuring a reasonably high level of service, yet the performance of such materials has to be balanced with their potential negative impacts on motor vehicles, transportation infrastructure, and the natural environment. In this context, this work presents a comprehensive and quantitative evaluation of snow and ice control chemicals currently used by various Idaho Transportation Department districts for highway maintenance operations, including rock salts (mainly solid sodium chloride), IceSlicer products (solid sodium chloride with trace amounts of other chlorides), and salt brines. The analysis has been enabled by the utilization of existing lab and field test data along with reasonable assumptions, in the effort to identify environmentally sustainable materials for winter highway operations. Despite its caveats, this case study is the first attempt to incorporate the most up-to-date information into a multicriteria decision making framework for the data-driven, holistic examination of various snow and ice control chemicals used by a maintenance agency. (C) 2014 American Society of Civil Engineers.
摘要：
This laboratory study explores the development of plastering mortar modified by feather fibers, so as to lay the groundwork for utilizing poultry feathers in thermal- insulation materials and removing them from waste streams. The laboratory testing measured the consistency value, porosity, compressive strength and thermal conductivity of various cement mortar mixes as a function of feather fiber dosage. The experimental data were used to determine the appropriate weight fraction of feather fibers in the mortars for thermal insulation. The results indicate that the incorporation of feather fibers decreased the consistency value of fresh mortar and increased the surface roughness and porosity of hardened mortar. Under the investigated conditions, as the content of admixed fiber increased, both the compressive strength and thermal conductivity of hardened mortar decreased remarkably before leveling off. The desirable dosage of feather fibers falls in the range of 0.2-0.7% by mass of dry mixture.
关键词：
anti-icing;winter road maintenance;snow and ice control;fixed automated spray technology;evaluation;antigivrage;entretien des routes en hiver;contrôle de la neige et de la glace;technologie d’arrosage automatisé fixe;évaluation
摘要：
This paper synthesizes information obtained from a comprehensive literature review and agency surveys on the state of the practice of fixed automated spray technology (FAST) systems. Experience with FAST systems in North America and Europe has revealed a mixed picture. On the one hand, several studies have indicated reductions in mobile operation costs and significant reductions in crash frequency, resulting in favorable benefit-cost ratios. On the other hand, there have been a variety of problems related to activation frequency, system maintenance and training. Installing a FAST system is complex and the challenges are often site specific. However, the evaluations cited show that FAST systems can be cost-beneficial if their locations are carefully chosen and if the system is supported with reliable environmental sensors. Finally, it was found that application of FAST systems in North America have recently increased.
作者机构：
School of Transportation, Southeast University, 2 Sipailou Nanjing, Jiangsu 210096.;School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan, China;Western Transportation Institute, PO Box 174250, College of Engineering, Montana State University, Bozeman, MT 59717-4250, USA;Civil Engineering Department, 205 Cobleigh Hall, Montana State University, Bozeman, MT 59717-2220, USA.;Western Transportation Institute, PO Box 174250, College of Engineering, Montana State University, Bozeman, MT 59717-4250, USA.
会议名称：
12th COTA International Conference of Transpoetation Professionals(CICTP2012)(第十二届COTA国际交通科技年会)
会议时间：
2012-08-03
会议地点：
北京
会议论文集名称：
12th COTA International Conference of Transpoetation Professionals(CICTP2012)(第十二届COTA国际交通科技年会)论文集
摘要：
Surface transportation in the U.S. is constantly threatened by the capricious character of weather. Improving the quality and accessibility of road and weather information may benefit a wide spectrum of weather data users. This paper presents a case study known as the proof-of-concept WeatherShare, an integrated, user-friendly surface transportation weather system for northern California. The goal of WeatherShare is to streamline and integrate currently available road weather data into one single source easily accessible by incident responders and potentially the traveling public, including those from Caltrans Road Weather Information Systems (RWIS), California Data Exchange Center, National Weather Service, among other providers in the region. To guide the system design and development, a Concept of Operations (ConOps) was developed to: 1) document the existing system; 2) identify the high-level needs to be addressed; 3) provide a conceptual overview of the desired system; 4) define users and operational scenarios of the proposed system; 5) present operational impacts of the proposed system; and 6) analyze advantages of the proposed system. This work demonstrates an innovative approach to developing a regional pilot weather information system, in which a systems engineering approach was used to incorporate stakeholder input and feedback throughout the iterative development process.
