Study on 3D Reconstruction of Ultrastructure Based on Scanning Electron Microscopy (SEM)
作者：
Pei, Guihong;Zhang, Jing;Liu, Jianjun;Zhang, Qinyi
期刊：
BASIC & CLINICAL PHARMACOLOGY & TOXICOLOGY ,2019年124(SUPPL-3):355-355 ISSN：1742-7835
作者机构：
[Pei, Guihong] Hubei Business Coll, Sch Architectural Econ & Engn Management, Wuhan, Hubei, Peoples R China.;[Zhang, Jing; Zhang, Qinyi] Southwest Petr Univ, Sch Civil Engn & Architecture, Chengdu, Sichuan, Peoples R China.;[Liu, Jianjun] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan, Hubei, Peoples R China.
语种：
英文
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Evaluation of stabilized graphite nanoplatelets: Dispersion quality and mechanical properties of cement composites
作者：
Qin, Xiantao* ;Zhu, Siyue;Zhang, Rongtang;He, Xiang;Jiang, Yi
期刊：
JOURNAL OF TESTING AND EVALUATION ,2019年47(5):3470-3479 ISSN：0090-3973
通讯作者：
Qin, Xiantao
作者机构：
[Zhu, Siyue; He, Xiang; Jiang, Yi; Qin, Xiantao; Zhang, Rongtang] Wuhan Polytech Univ, Sch Civil Engn & Architecture, 68 Xuefu South Rd, Wuhan 430023, Hubei, Peoples R China.;[Jiang, Yi] Purdue Univ, Sch Construct Management Technol, 401 N Grat St, W Lafayette, IN 47907 USA.
通讯机构：
[Qin, Xiantao] W;Wuhan Polytech Univ, Sch Civil Engn & Architecture, 68 Xuefu South Rd, Wuhan 430023, Hubei, Peoples R China.
关键词：
cement;graphite nanoplatelets;dispersion;surfactant;sonication;mechanical properties
摘要：
This study investigates the effect of adding a small concentration (0-0.5 wt. % addition by mass of cement) of graphite nanoplatelets (GNP) to cementitious materials. GNP-water-surfactant suspensions with various surfactant concentrations (0-20 mg/mL) and sonication times (0.5-6 h) are prepared and subjected to different protocols (long-term standing and centrifugation). Then, dispersion and stability are qualitatively observed through digital imaging and scanning electron microscopy after long-term standing and quantitatively evaluated by calculating the absorbance spectra ratio. Furthermore, the mechanical properties of GNP-reinforced cement (GNPRC) are investigated. The results show that 8 mg/mL and 4.5 h are the best choices for the surfactant concentration and sonication time, respectively. Also, obvious reinforcement for the mechanical properties of GNPRC is found;specifically, the 0.05 wt. % addition of GNP increases the compressive strength by 7.5 % and 16.7 % after 7 days and 28 days curing, respectively. Then, between the GNP dosages of 0 and 0.5 wt. %, the flexural strengths at 7 days and 28 days continuously increase, up to 55.6 % and 53.3 %, respectively.<br/> Copyright ©2019 by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959.
语种：
英文
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Study on the Properties and Mechanism of Mortars Modified by Super Absorbent Polymers
作者：
Li Faping;Liu Jiesheng*
期刊：
JOURNAL OF TESTING AND EVALUATION ,2019年47(2):1516-1532 ISSN：0090-3973
通讯作者：
Liu Jiesheng
作者机构：
[Li Faping; Liu Jiesheng] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Sch South Rd 68, Wuhan 430023, Hubei, Peoples R China.
通讯机构：
[Liu Jiesheng] W;Wuhan Polytech Univ, Sch Civil Engn & Architecture, Sch South Rd 68, Wuhan 430023, Hubei, Peoples R China.
关键词：
Early crack resistance;Mechanical property;Mortar;SEM;Super absorbent polymers
摘要：
The article investigated the influence of Super Absorbent Polymers (SAPs) with absorption behaviors on the consistency, fluidity, water absorption, mechanical properties, early crack resistance, permeability resistance, and degree of hydration of cementitious construction materials. Mechanical strength was investigated using a flexural and compressive strength test machine. Nonevaporable water content was employed to assess the degree of hydration of the cement powders. The durability of mortar was characterized using early crack resistance and a permeability resistance test. Furthermore, the micromechanism of mortars modified by SAPs and control mortars was researched using a Scanning Electron Microscope (SEM). Experimental results showed that for the SAPs and mix designs used in this article, the incorporation of SAPs generally reduced the mechanical strength and increased the consistency, fluidity, water absorption, and degree of hydration of modified mortars compared with control mortars. The durability of mortars incorporating SAPs was greatly improved. The connection of the macroproperty and micromechanism of mortars was researched using an SEM.
语种：
英文
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Effect of Modified Phosphogypsum on Properties of Cement Mortar
作者：
Gong, Xiaoqiang;Liu, Jiesheng* ;Zhang, Tongtong;Jiao, Zhu
期刊：
JOURNAL OF TESTING AND EVALUATION ,2019年48(4):2803-2812 ISSN：0090-3973
通讯作者：
Liu, Jiesheng
作者机构：
[Jiao, Zhu; Liu, Jiesheng; Gong, Xiaoqiang; Zhang, Tongtong] Wuhan Polytech Univ, Sch Engn & Architecture, Wuhan 430023, Peoples R China.
通讯机构：
[Liu, Jiesheng] W;Wuhan Polytech Univ, Sch Engn & Architecture, Wuhan 430023, Peoples R China.
关键词：
Activation index;Mechanical properties;Phosphogypsum
摘要：
The resource utilization of phosphogypsum (PG) can reduce the consumption of resources, turn waste into valuables, turn damage into profit, and form a green recycling economy of “resources-products-regenerated resources.” The article, combined with the comprehensive utilization of PG, analyzes the existing problems. Using lime neutralization to pretreat PG, the pH value, mortar consistency and setting time, activation index, and physical properties as well as the Fourier transform infrared spectroscopy and scanning electron microscopy examination with lime dosage are discussed. The results show that the performance of the obtained mixture powder activation index was better when it was weakly acidic; it is suggested that the optimal pH value range of lime neutralization for modified PG was about 4.52. The physical properties of PG are greatly affected by the lime content, and the influence mechanism was analyzed. It is anticipated that the results of the present study will be useful in utilizing the waste materials (fly ash, PG) for various geotechnical applications. Copyright © 2019 by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959
语种：
英文
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A study on numerical determination of permeability and inertia coefficient of aluminum foam using X-ray microtomography technique: Focus on inspection methods for reliability (permeability and inertia coefficient by tomography)
作者：
Celik, Hasan;Mobedi, Moghtada* ;Nakayama, Akira;Ozkol, Unver
期刊：
JOURNAL OF POROUS MEDIA ,2019年22(5):511-529 ISSN：1091-028X
通讯作者：
Mobedi, Moghtada
作者机构：
[Celik, Hasan; Ozkol, Unver] Izmir Inst Technol, Mech Engn Dept, TR-35430 Izmir, Turkey.;[Celik, Hasan; Nakayama, Akira] Shizuoka Univ, Dept Mech Engn, Naka Ku, 3-5-1 Joho Ku, Hamamatsu, Shizuoka 4328561, Japan.;[Mobedi, Moghtada] Shizuoka Univ, Fac Engn, Naka Ku, 3-5-1 Joho Ku, Hamamatsu, Shizuoka 4328561, Japan.;[Nakayama, Akira] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
通讯机构：
[Mobedi, Moghtada] S;Shizuoka Univ, Fac Engn, Naka Ku, 3-5-1 Joho Ku, Hamamatsu, Shizuoka 4328561, Japan.
关键词：
pore scale analysis;permeability;microtomography;porous media
摘要：
The volume-averaged (i.e., macroscopic) transport properties such as permeability and inertia coefficient of two aluminum foams with 10 and 20 pores per inch (PPI) pore density are found using microtomography images. It is shown that a comparison between the numerical values and the experimental results may not be sufficient to prove the correctness of the obtained results. Hence, in addition to traditional validation methods such as grid independency and comparison with reported results in literature, further inspections such as (a) checking the development of flow, (b) inspection of Darcy and non-Darcy regions, (c) conservation of flow rate through the porous media, (d) sufficiency of number of voxels in the narrow throats, and (e) observation of transverse velocity gradients in pores for high and low Reynolds numbers can be performed to further validate the achieved results. These techniques have been discussed and explained in detail for the performed study. Moreover, the obtained permeability and inertia coefficient values are compared with 19 reported theoretical, numerical, and experimental studies. The maximum deviation between the present results and the reported studies for 10 PPI is below 25%, while for 20 PPI it is below 28%.
语种：
英文
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An Analytical and Numerical Estimation of the Effective Thermal Conductivity of Complex Metal Frame Core Structures
作者：
Bai, X.;Nakayama, A.*
期刊：
Journal of Heat Transfer ,2019年141(2):024504-1-024504-5 ISSN：0022-1481
通讯作者：
Nakayama, A.
作者机构：
[Bai, X.] Shizuoka Univ, Grad Sch Sci & Technol, Naka Ku, 3-5-1 Johoku, Hamamatsu, Shizuoka 4328561, Japan.;[Nakayama, A.] Shizuoka Univ, Fac Engn, Naka Ku, 3-5-1 Johoku, Hamamatsu, Shizuoka 4328561, Japan.;[Nakayama, A.] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
通讯机构：
[Nakayama, A.] S;[Nakayama, A.] W;Shizuoka Univ, Fac Engn, Naka Ku, 3-5-1 Johoku, Hamamatsu, Shizuoka 4328561, Japan.;Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
关键词：
thermal conductivity;metal frame;lattice core;porous media
摘要：
An analytical and numerical study was conducted for estimation of the effective thermal conductivities of curved metal frame core structures, which can replace metal foams, in views of their advantages over the metal foams for both load bearing and heat dissipation. The trajectory of the frame ligament and its cross-sectional area were allowed to vary arbitrarily in the three-dimensional (3D) space. The analytical formula obtained by extending the formula previously proposed by Bai et al. (2017, "A General Expression for the Stagnant Thermal Conductivity of Stochastic and Periodic Structures," ASME J. Heat Transfer, 140(5), p. 052001) was examined by comparing it with the numerical results directly obtained from full 3D numerical computations. An air layer partially filled with a collection of coiled circular rods was treated both analytically and numerically. Furthermore, the effect of lattice nodes on the effective thermal conductivity was investigated by introducing an analytical model with the lattice ligaments merging together at one nodal point. The analytical expressions thus derived for the lattice structures with nodes were applied to tetrahedral structure and octet-truss structure to find their effective thermal conductivities, which are found to agree closely with the 3D numerical results. Thus, the present analytical expressions can be used to customize the structure to meet its desired thermal performance.<br/> ©2019 by ASME.
语种：
英文
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Durability of Concrete Incorporating Rice Husk Ashe
作者：
Li, Faping* ;Liu, Jiesheng;Gao, Xuan;Zhai, Jingwei;Liu, Yulin
期刊：
MATERIALS PERFORMANCE ,2019年58(3):52-56 ISSN：0094-1492
通讯作者：
Li, Faping
作者机构：
[Gao, Xuan; Li, Faping; Liu, Jiesheng; Zhai, Jingwei; Liu, Yulin] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan, Hubei, Peoples R China.
通讯机构：
[Li, Faping] W;Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan, Hubei, Peoples R China.
摘要：
Modified rice husk ash (RHA) concrete was prepared by adding different RHA dosages at different ternperatures into cementitious composites. The durability of the binders was characterized using a freeze-thaw test, coupled with compressive strength and weight loss testing and a permeability resistance test. The microstructure of modified concrete was investigated by scanning electron microscopy (SEM). Because of freezing and thawing, the compressive strength and weight loss ratios of the modified concrete were decreased compared with the control concrete. The experimental data revealed that the permeability resistance of the modified concrete was higher with the introduction of RHA. The SEM analysis indicates the behavior modification mechanism.
语种：
英文
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Study in the Durability of Silane-Based Mortar
作者：
Jiesheng Liu* ;Li Faping;Du Liwei;Liu Xiaofan;Zhang Rongtang
期刊：
JOURNAL OF TESTING AND EVALUATION ,2019年47(2):1502-1515 ISSN：0090-3973
通讯作者：
Jiesheng Liu
作者机构：
[Liu Xiaofan; Li Faping; Jiesheng Liu; Zhang Rongtang] Wuhan Polytech Univ, Sch Civil Engn & Architecture, 68 Sch South Rd, Wuhan 430023, Hubei, Peoples R China.;[Jiesheng Liu] Guangxi Key Lab Rd Struct & Mat, Guangxi 530007, Peoples R China.;[Du Liwei] Wuhan Wujiashan High Sch, 68 Sch South Rd, Wuhan 430023, Hubei, Peoples R China.
通讯机构：
[Jiesheng Liu] W;[Jiesheng Liu] G;Wuhan Polytech Univ, Sch Civil Engn & Architecture, 68 Sch South Rd, Wuhan 430023, Hubei, Peoples R China.;Guangxi Key Lab Rd Struct & Mat, Guangxi 530007, Peoples R China.
关键词：
durability;silane;mortar
摘要：
This article investigates the durability properties of mortar containing three types of silanes as integral additives. Compared with the plain mortar, mortar samples with silanes exhibited better performance when subjected to freezing-thawing cycles and chemical and carbonation corrosion. The addition of silanes also results in the formation of chemical bonding across the interface, which is helpful for improving crack resistance. Additionally, mortar samples with γ-Glycidoxypropyl methyldimethoxysilane (GDMMS) show better freezing-thawing resistance and chemical corrosion resistance than do mortar samples with γ-aminopropytriethoxysilane and 3-(Trimethoxysilyl)propyl methacrylate, because of the more effective interface between the GDMMS and mortar. For mortar samples with silanes, the effect of the types and quantity of silanes on the crack resistance of mortar and carbonation corrosion is not obvious. Scanning electron microscopy images show that silanes perform the networking and “coupling” effect to hold mortar particles, resulting in the improvement of mortar durability. Copyright © 2018 by ASTM International.
语种：
英文
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A comprehensive comparison between non-bulking and bulking aerobic granular sludge in microbial communities
作者：
He Qiulai* ;Zhang, Jing;Gao, Shuxian;Chen, Li;Lyu, Wanlin;...
期刊：
Bioresource Technology ,2019年294:122151 ISSN：0960-8524
通讯作者：
He Qiulai
作者机构：
[Yu, Jian; He Qiulai] Hunan Univ, Dept Water Engn & Sci, Key Lab Bldg Safety & Energy Efficiency, Minist Educ,Coll Civil Engn, Changsha 410082, Hunan, Peoples R China.;[Zhang, Jing] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430072, Hubei, Peoples R China.;[Gao, Shuxian] Univ Sci & Technol China, Dept Appl Chem, CAS Key Lab Urban Pollutant Convers, Hefei 230026, Anhui, Peoples R China.;[Hu, Xiaoling; Lyu, Wanlin; Chen, Rongfan; Wang, Hongyu; Zhang, Wei; Song, Jianyang; Chen, Li] Wuhan Univ, Sch Civil Engn, Wuhan 430072, Hubei, Peoples R China.
通讯机构：
[He Qiulai] H;Hunan Univ, Dept Water Engn & Sci, Key Lab Bldg Safety & Energy Efficiency, Minist Educ,Coll Civil Engn, Changsha 410082, Hunan, Peoples R China.
关键词：
Aerobic granular sludge;Bacterial community;Extracellular polymeric substances;Filamentous bulking;H(2)O(2)
摘要：
Filamentous sludge bulking poses great threats to operational stability of aerobic granular sludge. Exploration of the microbial community aids knowledge of the causative factors to sludge bulking and guides directions for corresponding actions for prevention and controlling. Detailed changes of bacterial community within the non-bulking and bulking were performed and compared with a non-specific method through 1‰ (v/v) hydrogen peroxide (H2O2) addition. Results revealed that non-bulking/bulking granules maintained effective carbon and nitrogen removal, while bulking completely deteriorated enhanced biological phosphorus removal (EBPR). Excess extracellular polymeric substances (EPS) especially polysaccharide (PS) were directly linked with sludge bulking and abundant PS contributed to subsequent granular re-stability. Filamentous bulking dramatically altered the bacterial populations and 1‰ H2O2 effectively controlled bulking by eliminating causative filaments Singulisphaera and Thiothrix. Together, this study provides new insights into the non-bulking/bulking granules and could direct the prevention and control of filamentous bulking in aerobic granules. © 2019 Elsevier Ltd
语种：
英文
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Experimental research in the phase change materials based on paraffin and expanded perlite
作者：
Liu Jiesheng* ;Li Faping;Gong Xiaoqiang;Zhang Rongtang
期刊：
Phase Transitions ,2018年91(6):631-637 ISSN：0141-1594
通讯作者：
Liu Jiesheng
作者机构：
[Li Faping; Liu Jiesheng; Zhang Rongtang; Gong Xiaoqiang] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430040, Hubei, Peoples R China.
通讯机构：
[Liu Jiesheng] W;Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430040, Hubei, Peoples R China.
关键词：
Phase change materials;expanded perlite;paraffin
摘要：
In this study, paraffin (PA)/expanded perlite (EP) form-stable phase change material (PCM) was first fabricated using the direct impregnation method without vacuum treatment. Absorptive capacity results showed that the PA/EP composite can obtain good absorptive capacity with the temperature 80 °C and the time 2 h. Compared with the water absorption of EP, the decrease in the water absorption of PA/EP form-stable proved that the absorption of PA into porous EP has been carried out successfully. Scanning electron microscope (SEM) and Fourier transform infrared (FT-IR) results show that paraffin can be well impregnated into EP pores and has good compatibility with it. Differential scanning calorimetry (DSC) results reveal that paraffin/EP composite PCM has melting temperature and latent heat of 53.6 °C and 91.3 J/g, respectively. The durability cycles results suggest that form-stable PA/EP PCM shows good durability. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.
语种：
英文
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A numerical study on determination of volume averaged thermal transport properties of metal foam structures using X-ray microtomography technique
作者：
Celik, Hasan;Mobedi, Moghtada* ;Nakayama, Akira;Ozkol, Unver
期刊：
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS ,2018年74(7):1368-1386 ISSN：1040-7782
通讯作者：
Mobedi, Moghtada
作者机构：
[Celik, Hasan; Ozkol, Unver] Izmir Inst Technol, Mech Engn Dept, Izmir, Turkey.;[Mobedi, Moghtada; Celik, Hasan; Nakayama, Akira] Shizuoka Univ, Fac Engn, Naka Ku, 3-5-1 Johoku, Hamamatsu, Shizuoka 4328561, Japan.;[Nakayama, Akira] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan, Hubei, Peoples R China.
通讯机构：
[Mobedi, Moghtada] S;Shizuoka Univ, Fac Engn, Naka Ku, 3-5-1 Johoku, Hamamatsu, Shizuoka 4328561, Japan.
摘要：
Volume averaged thermal transport properties of two metal foams with 10 and 20 PPI are obtained by using microtomography technique. The digital 3D structures of samples are generated in computer environment. The governing equations are solved for the entire domain and the volume averaged technique is used to determine interfacial heat transfer coefficient, longitudinal and transverse thermal dispersion conductivity. The study is performed for the pore scale Reynolds number from 100 to 600. The obtained results are within the ranges of the suggested correlations in literature. The present study supports the correlations suggested by Calmidi and Mahajan (2000) and Zhang et al. (2016). © 2018, © 2018 Taylor & Francis Group, LLC.
语种：
英文
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A numerical investigation of charged ion transport in electrodialyzers with spacers
作者：
Bai, Xiaohui;Nakayama, Akira*
期刊：
Desalination ,2018年445:29-39 ISSN：0011-9164
通讯作者：
Nakayama, Akira
作者机构：
[Bai, Xiaohui; Nakayama, Akira] Shizuoka Univ, Dept Mech Engn, Naka Ku, 3-5-1 Johoku, Hamamatsu, Shizuoka 4328561, Japan.;[Nakayama, Akira] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
通讯机构：
[Nakayama, Akira] S;[Nakayama, Akira] W;Shizuoka Univ, Dept Mech Engn, Naka Ku, 3-5-1 Johoku, Hamamatsu, Shizuoka 4328561, Japan.;Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
关键词：
Current density;Electrodialyzer;Ion transport;Numerical analysis
摘要：
Charged ion transport in electrodialyzers with ion mixing spacers was numerically investigated solving Navier-Stokes and Nernst-Planck equations in a three-dimensional Cartesian coordinate system. An electrically nonconductive spacer placed in the membrane channels in the electrodialyzer enhances three-dimensional hydrodynamic and ionic mechanical dispersion, resulting in a substantial increase in the effective mass transfer coefficient over the membrane surfaces. This mechanical dispersion retards depletion of ions and increases the value of the limiting current density, which is of great importance in practical applications of electrodialyzers. Full detailed three-dimensional numerical computations were conducted, for the first time, to investigate the effect of the ion mixing spacers on the limiting current density, using a voxel method based on Cartesian staggered grids along with no-slip velocity and harmonic mean averaging boundary treatments. The results obtained from the three-dimensional numerical simulation were found in good agreement with the experimental data available in the literature. © 2018 Elsevier B.V.
语种：
英文
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Experimental Study in the Modification of Mortar Samples with Incorporated Rice Husk
作者：
Liu, Jiesheng* ;Li, Faping;He, Xiang;Liu, Xiaofan;Zhang, Rongtang
期刊：
JOURNAL OF TESTING AND EVALUATION ,2018年46(3):967-973 ISSN：0090-3973
通讯作者：
Liu, Jiesheng
作者机构：
[He, Xiang; Liu, Jiesheng; Li, Faping; Liu, Xiaofan; Zhang, Rongtang] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
通讯机构：
[Liu, Jiesheng] W;Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
关键词：
modification;mortar;physical properties;rice husk
摘要：
The aim of this work is to investigate the influence of rice husk (RH) on the properties of mortar. Two different RH were used as integral additives in the mortar samples: Direct natural RH addition to the mortar and the use of pretreated RH. The results of such modification are described, taking into consideration the interaction between the RH and mortar. In addition, the physical properties, visual observation and microstructure of mortar prepared with different amount of modified RH were experimentally studied. The test results indicated that modification of RH enhanced the interaction between the RH and mortar because of the impurities removal and rougher surface. Comparing with the natural RH, the modification of RH increases the density and the mechanical properties. The addition of RH can increase the pore number of the mortar mixture, resulting in decrease in the density and mechanical properties of mortar. Morphology characterization results showed that the modification of RH results in an improvement in the interaction between the RH and mortar and further increase in RH content increases the number of pores in the mortar structure. © 2018 by ASTM International.
语种：
英文
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High temperature properties of high viscosity asphalt based on rheological methods
作者：
Qin Xiantao* ;Zhu Siyue;He Xiang;Jiang Yi
期刊：
Construction and Building Materials ,2018年186:476-483 ISSN：0950-0618
通讯作者：
Qin Xiantao
作者机构：
[He Xiang; Zhu Siyue; Jiang Yi; Qin Xiantao] Wuhan Polytech Univ, Sch Civil Engn & Architecture, 68 Xuefu South Rd, Wuhan 430023, Hubei, Peoples R China.;[Jiang Yi] Purdue Univ, Sch Bldg Construct Management, W Lafayette, IN 47906 USA.
通讯机构：
[Qin Xiantao] W;Wuhan Polytech Univ, Sch Civil Engn & Architecture, 68 Xuefu South Rd, Wuhan 430023, Hubei, Peoples R China.
关键词：
Burgers model;Creep compliance;High viscosity asphalt;Repeated creep and recovery test
摘要：
This research aims to comparatively evaluate the high temperature properties of modified high viscosity asphalt (SHVA) by temperature and frequency sweep testing as well as repeated creep and recovery testing. Wheel-tracking testing was also introduced to verify anti-rutting properties of asphalt mixtures. The results indicated that the phase angles (δ) of high viscosity asphalts decreased with increased temperature. The lowest decrease rate of the complex modulus (G∗) reflected that SHAV had the lowest temperature susceptibility. The δ of neat asphalts were nearly unchanged with increased frequency, while the δ of modified asphalts clearly increased. Both temperature and frequency sweep tests indicated that improvements in anti-rutting performance (i.e., smaller δ and bigger G∗) of high viscosity asphalt were noticeable. Burgers model and a piecewise linear regression method showed high accuracy in simulating asphalt's creep process. Changes in binder creep stiffness and accumulated strain (i.e. 2.8, 2.6, and 2.4% for SBS, TPS and SHAV, compared to 96.4 and 102.9% for two neat asphalts) demonstrated that the polymer used in these modified asphalts significantly enhanced their stiffness and elastic properties. From the analysis of creep compliance, SHVA had the maximum elastic and minimum viscous proportions in comparison with the other four asphalts. Test results of the mixtures showed that the asphalt mixture with SHVA possessed the best high-temperature stability (9265 cycles/mm). Good agreement was found between the high temperature properties of the asphalts and mixtures. © 2018 Elsevier Ltd
语种：
英文
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Forced Convective Heat Transfer in a Channel Filled With a Functionally Graded Metal Foam Matrix
作者：
Bai, Xiaohui;Kuwahara, Fujio;Mobedi, Moghtada;Nakayama, Akira*
期刊：
Journal of Heat Transfer ,2018年140(11):111702 ISSN：0022-1481
通讯作者：
Nakayama, Akira
作者机构：
[Mobedi, Moghtada; Kuwahara, Fujio; Bai, Xiaohui; Nakayama, Akira] Shizuoka Univ, Dept Mech Engn, 3-5-1 Johoku, Hamamatsu, Shizuoka 4328561, Japan.;[Nakayama, Akira] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
通讯机构：
[Nakayama, Akira] S;[Nakayama, Akira] W;Shizuoka Univ, Dept Mech Engn, 3-5-1 Johoku, Hamamatsu, Shizuoka 4328561, Japan.;Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
关键词：
functionally graded metal foam;forced convection;heat transfer enhancement
摘要：
Fully developed forced convective heat transfer within a channel filled with a functionally graded metal foam matrix was investigated analytically for the case of constant wall heat flux. A series of functionally graded metal foam matrices of the same mass (i.e., the same solidity) were examined in views of their heat transfer performances. The porosity either increases or decreases toward the heated wall following a parabolic function. Among the metal foam matrices of the same mass, the maximum heat transfer coefficient exists for the case in which the porosity decreases toward the heated wall (i.e., more metal near the wall). The heat transfer coefficients in such channels filled with a functionally graded metal foam matrix are found 20-50% higher than that expected from the increase in the effective thermal conductivity. Hence, functionally graded metal foam matrices are quite effective to achieve substantially high heat transfer coefficient with an acceptable increase in pressure drop.
语种：
英文
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An Experimental Study of Mineral and Microstructure for Undisturbed Loess Polluted by Landfill Leachate
作者：
Lu, Haijun;Xu, Shicheng* ;Li, Dinggang;Li, Jixiang
期刊：
KSCE Journal of Civil Engineering ,2018年22(12):4891-4900 ISSN：1226-7988
通讯作者：
Xu, Shicheng
作者机构：
[Lu, Haijun; Li, Dinggang; Xu, Shicheng; Li, Jixiang] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
通讯机构：
[Xu, Shicheng] W;Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
关键词：
undisturbed loess;landfill leachate;strength;microstructure
摘要：
To investigate the shear strength and microstructure of undisturbed loess polluted by landfill leachate, a series of laboratory tests were carried out to determine the shear strength, mineral composition, surface morphology, particle size distribution and pore characteristics of the loess. The stress-strain curve of undisturbed soil polluted by landfill leachate showed typical strain-softening behavior. The deviatoric stress, cohesion and angle of shearing resistance of undisturbed soil decreased at increased landfill leachate concentrations, decreased by 31.03%, 30.01%, respectively. But pore water pressure was positively related to leachate concentrations. The content of primary minerals remained stable, and the content of montmorillonite and illite decreased with increased leachate concentration, reduced by 26.02%, 23.93%, respectively. Soil structure changed into an unstable honeycomb structure when the leachate concentration increased. Moreover, the average particle size decreased by 62.1%, and the specific surface area increased and then stabilized at 500 similar to 650 m(2)/kg. The soil particles became nonuniform and porous and their sizes gradually decreased. The pore radius of soil mainly ranged from 0.02 mu m to 1 mu m. The maximum radius and optimal radius of the pore increased when the leachate concentrations increased.
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英文
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Properties of Cement Mortar with Different Blending Amount of Rich Husk Ash (RHA)
作者：
Xing, Shanshan;Dong, E.;Liu, Jiesheng* ;Yu, Yuanyuan
期刊：
JOURNAL OF TESTING AND EVALUATION ,2018年47(1):525-536 ISSN：0090-3973
通讯作者：
Liu, Jiesheng
作者机构：
[Xing, Shanshan; Liu, Jiesheng; Yu, Yuanyuan; Dong, E.] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan Changqing Pk,Southern Rd 68, Wuhan 430023, Hubei, Peoples R China.
通讯机构：
[Liu, Jiesheng] W;Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan Changqing Pk,Southern Rd 68, Wuhan 430023, Hubei, Peoples R China.
关键词：
Dry bulk density;Mortar consistency;Rice husk ash;Strengths test;Water absorption;Water permeability
摘要：
The morphology of rice husk ash (RHA) samples obtained at 400°C in a vertical high temperature furnace was characterized by scanning electron microscopy, and the effect of RHA on the mechanical behavior of cement mortar was studied. The RHA sample is slightly grey in color and there are some black particles. RHA samples have many sheets that are vertically and horizontally interlaced. The effect of RHA on the compressive and flexural strengths test for cement mortar has been investigated. The water absorption, mortar consistency, dry bulk density, and water permeability were tested. The compressive and flexural strengths decreased with the replacement of RHA. The mortar consistency improved, and water absorption increased. The dry bulk density of cement mortar decreased, and the water permeability increased. Because RHA is a resource containing properties that have the potential for categorizing it as waste, the comprehensive utilization of RHA is significant for improving environmental protection and gaining economic benefits.<br/> Copyright ©2018 by ASTM International
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英文
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An Experimental Study on Cement-Solidified Cd-Contaminated Soils under Drying-Wetting Cycles
作者：
Liu, Huikai;Lu, Haijun* ;Zhang, Xiong;Li, Jixiang;Wang, Weiwei
期刊：
JOURNAL OF TESTING AND EVALUATION ,2018年46(2):493-506 ISSN：0090-3973
通讯作者：
Lu, Haijun
作者机构：
[Lu, Haijun; Liu, Huikai; Wang, Weiwei; Li, Jixiang; Zhang, Xiong] Wuhan Polytech Univ, Inst Poromech, 68 South Rd, Wuhan 430023, Hubei, Peoples R China.
通讯机构：
[Lu, Haijun] W;Wuhan Polytech Univ, Inst Poromech, 68 South Rd, Wuhan 430023, Hubei, Peoples R China.
关键词：
Cd-contaminated soil;crack;drying-wetting cycle;hydraulic conductivity;leaching concentration;pore
摘要：
Many human activities can produce and release cadmium (Cd) to air, water, and soils. Soils are the major sink for Cd released into the environment. Unlike organic contaminants, which are oxidized to carbon (IV) oxide by microbial action, Cd does not undergo microbial or chemical degradation, and its total concentration in soils persists for a long time after introduction. The excessive presence of Cd in soil poses great risks and hazards to human health and is detrimental to the ecosystem. In the past 50 years, cement-based solidification/stabilization (S/S) of heavy metal-contaminated soil has received increasing research attention, and its application has expanded because of its advantages over many other existing methods such as relatively low cost, good long-term effectiveness and performance, ready commercial availability, general acceptance by the public, etc. However, considering the lasting effect and environmental impact of the S/S method, as well as the complicated surroundings of cement-solidified Cd-contaminated soils, further research is needed. In this study, a comprehensive series of tests such as low-temperature nitrogen gas adsorption/desorption, permeability, and Cd leaching were performed to investigate the performance of Cd-contaminated soils solidified with 2 %, 5 %, 8 %, and 10 % of cement during a various number of drying-wetting (D-W) cycles. The focus was put on the cracking occurrences and evolution with the number of D-W cycles, their influences on the pore/crack size and distribution, hydraulic conductivity, and final concentration of Cd leaching. Based upon the analyses of the test results, some conclusions are drawn and the optimum percentage of cement treatment was suggested for the soils under investigation. © 2018 by ASTM International.
语种：
英文
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A General Expression for the Stagnant Thermal Conductivity of Stochastic and Periodic Structures
作者：
Bai, X.;Hasan, C.;Mobedi, M.;Nakayama, A.*
期刊：
Journal of Heat Transfer ,2018年140(5):052001 ISSN：0022-1481
通讯作者：
Nakayama, A.
作者机构：
[Bai, X.] Shizuoka Univ, Grad Sch Sci & Technol, Naka Ku, 3-5-1 Johoku, Hamamatsu, Shizuoka 4313192, Japan.;[Hasan, C.] Izmir Inst Technol, Dept Mech Engn, TR-35430 Urla, Turkey.;[Mobedi, M.; Nakayama, A.] Shizuoka Univ, Fac Engn, Naka Ku, 3-5-1 Johoku, Hamamatsu, Shizuoka 4328561, Japan.;[Nakayama, A.] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
通讯机构：
[Nakayama, A.] S;[Nakayama, A.] W;Shizuoka Univ, Fac Engn, Naka Ku, 3-5-1 Johoku, Hamamatsu, Shizuoka 4328561, Japan.;Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan 430023, Hubei, Peoples R China.
关键词：
thermal conductivity;metal foam;lattice truss structure;porous media
摘要：
A general expression has been obtained to estimate thermal conductivities of both stochastic and periodic structures with high-solid thermal conductivity. An air layer partially occupied by slanted circular rods of high-thermal conductivity was considered to derive the general expression. The thermal conductivity based on this general expression was compared against that obtained from detailed three-dimensional numerical calculations. A good agreement between two sets of results substantiates the validity of the general expression for evaluating the stagnant thermal conductivity of the periodic structures. Subsequently, this expression was averaged over a hemispherical solid angle to estimate the stagnant thermal conductivity for stochastic structures such as a metal foam. The resulting expression was found identical to the one obtained by Hsu et al., Krishnan et al., and Yang and Nakayama. Thus, the general expression can be used for both stochastic and periodic structures.
语种：
英文
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Investigation on punching behavior of pile cap under column reinforced by section steel truss
作者：
Guo, Honglei*
期刊：
ACI Structural Journal ,2018年115(2):379-390 ISSN：0889-3241
通讯作者：
Guo, Honglei
作者机构：
[Guo, Honglei] Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan, Hubei, Peoples R China.
通讯机构：
[Guo, Honglei] W;Wuhan Polytech Univ, Sch Civil Engn & Architecture, Wuhan, Hubei, Peoples R China.
关键词：
bearing capacity;pile cap;punching;section steel truss;strut-and-tie
摘要：
Despite many investigations on the spatial strut-and-tie mechanical mechanism on pile cap punching failure at present, little has been reported on its application. Meanwhile, compared with the steel-reinforced concrete structure extensively existing in the superstructure, that in the foundation structure is yet seldom seen. The real section steel truss of better material properties was used to replace the virtual truss originally regarded as the concrete stress flow for this reason. Aiming at the punching-force bearing behavior of this kind of the pile cap reinforced by the section steel truss, two series (the first is four six-pile caps and the second is two four-pile caps) of the full-size experimental study and the theoretical analysis have been made. Under the condition of the same reinforcing steel amount, in contrast to the ordinary reinforced pile cap, this kind of the section steel truss pile cap can increase the bearing capacity and ductility. It transfers load according to the spatial strut-and-tie. Before a definite column load, the column load is born jointly by the section steel truss and the concrete spatial strut-and-tie. Then, after the concrete strut is decomposed into the two ones coupled at the two ends, the section steel truss gradually shifts into the bearing main-body. With the total yield of the section steel strut and the complete damage to the concrete strut of the splitting in the midpart plus the shear-compression at the two ends, the punching cone is formed. The failure to the composite strut of the section steel and the concrete is an indication of the loss of the pile cap punching bearing capacity. The bearing capacity calculation formulas were deduced based on this, which agree well with the test results. Copyright © 2018, American Concrete Institute. All rights reserved.
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英文
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