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Dynamic Mechanical Characterizations and road performances of Flame Retardant Asphalt Mortars and Concretes

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Journal of Wuhan University of Technology(Materials Science) 2015年第5期30卷 1036-1042页

作者：秦先涛 ZHU Siyue LI Zuzhong CHEN Shuanfa School of Highway Chang'an University School of Civil Engineering and Architecture Wuhan Polytechnic University School of Materials Science and Engineering Chang'an University Engineering Research Center of Transportation Materials of Ministry of Education Chang'an University

To research the dynamic mechanical properties and road performances of flame retardant asphalt mortars and mixtures, four different asphalt mortars/mixtures were prepared: a reference group and three asphalt mortars/mixtures containing composite flame retardant materials(M-FRs) of different proportions. Temperature sweep, frequency sweep, repeated creep test, force ductility test and bending beam rheological test were carried out to research the dynamic mechanical properties of asphalt mortars containing M-FRs; wheeltracking test, low-temperature bending test and freeze-thaw split test were used to study the road performances of asphalt mixtures containing M-FRs. The results show that high-temperature performances of the three flame retardant asphalt mortars improve greatly, while low-temperature cracking resistances decline. Both hightemperature performances and water stabilities of asphalt mixtures containing M-FRs are quite good and exceed the specification requirements. However, their low-temperature performances decline in different degrees. In summary, besides their good flame retardancy, the flame retardant asphalt mortars and mixtures also exhibit acceptable road performance.

关键词： asphalt mortar asphalt mixture composite flame retardant materials dynamic mechanical characterization road performance

Evaluating Contractors’ Safety Record and Its Influence on performance of road Infrastructural Projects

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World Journal of Engineering and Technology 2021年第2期9卷 203-228页

作者： James Mushori Charles Mallans Rambo Charles Misiko Wafula Johnson Matu Project Planning and Management University of Nairobi Nairobi City Kenya School of Open and Distance Learning University of Nairobi Nairobi City Kenya

A number of studies conducted in Kenya and internationally indicated that most of the construction firms and contractors do not seem to strictly observe safety administration in construction industry, hence compromised performance at implementation stage of projects and even later in the post implementation or post-delivery stage. The study aimed to examine the influence of contractors’ safety record on road performance. This is to create better understanding of how the safety record of contractors could either positively or negatively influence performance of roads during post-delivery stage. The study used both descriptive survey research design and correlation design based on a pragmatic mixed method approach. Through stratified sampling and proportionate sampling, a sample of 210 was drawn from a population of 460 comprising of registered contractors and Public Service Vehicles (PSV) drivers within Nairobi County in Kenya. Questionnaires were distributed using simple random sampling. The questionnaires returned were 153 in total representing 72.8% of all questionnaires distributed to the respondents. Data was descriptively analyzed using percentages, frequencies, means and standard deviations for measuring central tendency and variability. Inferential analysis was done by use of correlation and regression. The descriptive analysis revealed that safety policy management system, insurance policy, and adequacy of standards in addressing safety outcome are to some extent practiced and adhered to. However, compliance behavior to safety procedures is still weak and requires improvement. The null hypothesis was tested and the results obtained from a simple linear regression indicated that, R = 0.657, R2

关键词： Contractors’ Safety Record road performance road Safety Infrastructural Projects

An investigation on modification mechanism of CH2O-modified low temperature coal tar pitches

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Frontiers of Structural and Civil Engineering 2017年第3期11卷 293-300页

作者： Qiang XIN Shanghong HUANG College of Civil Engineering Tongji University Shanghai 200092 China lnner Mongolia Communications Design and Research Institute Co. LTD Huhhot 010010 China National Center for Material Service Safety University of Science and Technology Beijing Beijing 100083 China

Rising oil price has brought huge cost pressure for low grade highway construction, and it is urgent to find alternative resources. At the same time, there are nearly 50000-60000 tons of low temperature coal output in inner Mongolia region, China, which has high toxicity and high polluting. To make the low temperature coal be applicable for road constructions, the formaldehyde is used as cross linking agent, the concentrated sulfuric acid is used as catalyst, and the chemical modification of low temperature coal tar pitch in Inner Mongolia region is investigated. The road performance （softening point, penetration and ductility） of modified low temperature coal are tested. Results shown that the road performance of modified low temperature coal is increased significantly. Modification mechanism of low temperature coal is studied by Scanning Electron Microscopy and other analytical tools. Results show that, in the modified low temperature coal, resin content increases and the resin fiber diameter becomes larger with the increasing of formaldehyde content.

关键词： low temperature coal tar pitch modification road performance

Review on application of phase change materials in asphalt pavement

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Journal of Traffic and Transportation Engineering(English Edition) 2023年第2期10卷 185-229页

作者： Xiaoqing Wang Biao Ma Siqi Li Wei Si Kun Wei Hongfei Zhang Xueyan Zhou Yunfeng Fang Xingxiang Kang Wenshuo Shi Key Laboratory for Special Area Highway Engineering of Ministry of Education Chang’an UniversityXi’an 710064China School of Modern Post Xi’an University of Posts&TelecommunicationsXi’an 710064China School of Transportation Southeast UniversityNanjing 211189China Dongtai Highway Development Center Dongtai 224200China

Phase change materials(PCMs)can regulate the temperature in asphalt pavement and minimize temperature-related problems,such as rutting and thermal cracking,because of their ability to store and release latent *** PCMs can also enable additional road surface functions,such as snow melting ability,freeze-thaw cycle resistance,and heat island *** functions are helpful in achieving intelligent,green,and sustainable transportation *** the research on PCMs for asphalt pavement has been carried out for more than 10 years,a systematic material system and mature application technology have not yet been *** main reasons for restricting the development of this technology include the lack of suitability between the PCMs and asphalt pavement,the quantitative characterization of phase change temperature regulation property,and the evaluation of the effect of phase change energy storage on improving pavement *** the published review has made a comprehensive summary of the existing research,it has yet to identify the key restricting the development of this technology and carry out a review and discussion based on *** grasp the development status of the application of PCMs in asphalt pavement,sort out the development needs and break through the technical barriers,this study systematically summarizes the preparation and performance of PCMs for asphalt pavement,compares the performance and evaluation methods of asphalt mixtures with different PCMs,and summarizes the numerical simulation methods of phase change asphalt ***,this study presents potential approaches to address critical technical issues and discusses possible future research.

关键词： Asphalt mixture Phase change material road performance Thermal performance Thermoregulation

A comprehensive review of bio-oil, bio-binder and bio-asphalt materials: Their source, composition, preparation and performance

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Journal of Traffic and Transportation Engineering(English Edition) 2022年第2期9卷 151-166页

作者： Zhengqi Zhang Ying Fang Jianhua Yang Xinjun Li Key Laboratory for Special Area Highway Engineering of Ministry of Education Chang’an UniversityXi'an 710064China

To promote the application of bio-materials and provide a direction for their further researches,this paper comprehensively summarizes the research progress of biomaterials in recent *** review results show that bio-oil is a mixture obtained from different biomasses through pyrolysis,alcoholysis,acidolysis,high liquefaction,etc.,and those biomasses mainly include wood fiber type,waste oil type and animal manure *** refers to the product of bio-oil processed by distillation,extraction oxidation and polymer modification,and it can be served as a modifier,diluent or substitute material of asphalt;the main chemical components of bio-oil include ethers,esters,aldehydes,ketones,phenols,organic acids,alcohols and ***-asphalt is obtained by adding biobinder into the petroleum asphalt for modification or blending,and the shear temperature and shear rate of bio-asphalt derived from wood fiber type and waste oil type are usually higher than that of bio-asphalt derived from swine *** with petroleum asphalt,bio-asphalt binder usually shows lower high-temperature performance as well as higher low-temperature performance and aging ***,bio-asphalt mixture generally exhibits lower high-temperature stability,higher low-temperature crack resistance and water stability than petroleum asphalt *** studies should be conducted combining with the source,composition,preparation,properties and oil production rate of ***,how to raise the bio-binder content in bio-asphalt as much as possible while ensuring the sufficient performance becomes the focus of future ***,the micro reaction mechanism between bio-binder and petroleum asphalt should be illustrated in ***,developing a complete and unifying technical standard and application specification of bio-asphalt technology is necessary for future ***,determining the optimum bio-binder potentially used as the substitute of petroleum aspha

关键词： Bio-oil Bio-binder Bio-asphalt road performance Environmental protection

Preparation and Analysis of Carbon Fiber-Silicon Carbide Thermally Conductive Asphalt Concrete

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Fluid Dynamics & Materials Processing 2024年第4期20卷 705-723页

作者： Zhiyong Yang Enjie Hu Lei Xi Zhi Chen Feng Xiong Chuanhai Zhan School of Civil Engineering and Environment Hubei University of TechnologyWuhan430068China

An experimental investigation into the thermal conductivity of CF-SiC two-phase composite asphalt concrete is *** main objective of this study was to verify the possibility of using SiC powder instead of mineral powder as the thermal conductive filler to prepare a new type of asphalt concrete and improve the efficiency of electrothermal snow and ice melting systems *** thermal conductivity of asphalt concrete prepared with different thermally conductive fillers was tested by a transient plane source method,and the related performances were *** the temperature rise rate and surface temperature were studied through field heating ***,the actual ice melting efficiency of the thermally conductive asphalt concrete was evaluated using an effective electrothermal *** shown by the experimental results,the composite made of SiC powder and carbon fiber has a high thermal *** SiC replaces mineral powder,the thermal conductivity of the asphalt mixture increases first and then decreases with the increase of carbon fiber *** the present study,in particular,the thermal conductivity attained a peak when the carbon fiber content was 0.2%of the aggregate mass.

关键词： Carbon fiber silicon carbide thermally conductive asphalt concrete road performance electrothermal snow melting