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International Conference on Smart City and Systems engineering (ICSCSE)

作者： Yanfang Liu Wenxue Zhang Weigang Bao China Communications Construction Company Limited Beijing China College of Architecture and Civil Engineering Beijing University of Technology Beijing China

ISBN: (纸本)9781728113678;9781728113661

In order to study the seismic response characteristics of extradosed cable-stayed bridges with continuous system for different seismic isolation design scheme. A parametric study, based on the nonlinear dynamic time history analysis method, is conducted to investigate the contribution of the bearings on the seismic response of five typologies of the extradosed cable-stayed bridges. The analysis results showed that the other isolation design scheme can effectively control the relative displacement of the beam end, which compared with the JQZ scheme; The FZQZ scheme can effectively coordinate the force between the piers and play the seismic potential of the pier, which can be applied to the different characteristics of the ground motions. For the system, is a more ideal antiseismic design.

关键词： Bridges Structural beams Force History Load modeling Stress Energy dissipation

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Profitability Analysis and Assessment of the Possibility of Applying Renovation and Modernization Measures to Improve the Utility Value of Public Buildings

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IOP Conference Series: Materials Science and engineering 2019年第3期603卷

作者： Robert Bucon Lublin University of Technology Faculty of Civil Engineering and Architecture Department of Construction Methods and Management Lublin Poland

Utility building value depends, among other things, on the renovation and modernization activities undertaken at the maintenance stage. They result from a correct assessment of the building condition. Lack of appropriate methods, which in a comprehensive way, taking into account the utility requirements for these buildings, would allow to assess the condition of buildings is one of the main reasons for negligence in the proper maintenance of public buildings. With this in mind, the author carried out a study aimed at an in-depth analysis and assessment of the possibility of applying renovation and modernization measures in relation to the improvement of the utility value of the building and the cost of their implementation. As part of the research, a mathematical model was first developed, which was used to carry out the research. As part of the development of the model, a set of criteria relating to technical-utility, economic and environmental requirements was selected and a method for their evaluation was developed. Next, proposals of renovation and modernization activities were presented, the aim of which is to improve the utility value ratio of the building. For its evaluation the method based on the theory of fuzzy sets was used, which at the stage of inference uses expert knowledge included in the fuzzy rules database. The calculated utility value of the proposed renovation and modernization activities is the basis for further research analyses. Optimization tasks consisting in the selection of an appropriate repair variant are carried out by means of appropriate optimization methods. The adopted optimization objectives concerned both the possibility of improving the assumed increase in utility value and limitations in their financing. The assessment of utility value of public utility buildings, which has not been carried out yet, taking into account the current legal and utility requirements, will allow to determine the impact of renovation and modernization

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On-line prediction model for rate of penetration (ROP) with cumulating field data in real time 4

On-line prediction model for rate of penetration (ROP) with ...

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4th ISRM Young Scholars Symposium on Rock Mechanics, YSS 2017

作者： Diaz, Melvin B. Kim, Kwang Yeom Shin, Hyu Soung University of Science and Technology Korea Republic of Korea Institute of Civil Engineering and Construction Technology Korea Republic of

ISBN: (纸本)9791156103158

We present an optimized training and prediction model for Rate of Penetration (ROP) forecasting using on-line artificial neural network (ANN) in real-time. The technique aims to assist decision making on drilling operations by predicting ROP under a given set of drilling conditions. The scenario modeler relies on real time drilling data analysis, and it is capable of handling cumulative information analysis in real time for ROP prediction within the same well, but also can consider drilling data gained from other fields under similar conditions. The real time prediction model has been applied to drilling data coming from a geothermal project of over 4 km depth, located in the Pohang, Republic of Korea. The observed results with respect to data intervals or sections set the basis for further adjustments to the model, and encourages its use in different drilling situations. © 2017 by Korean Society for Rock Mechanics.

关键词： Forecasting

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Success Factors of Design-Build Public Sector Projects in Malaysia

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IOP Conference Series: Materials Science and engineering 2020年第1期712卷

作者： Z P Lee R A Rahman S I Doh Construction Management Research Group Faculty of Civil Engineering Technology Universiti Malaysia Pahang 26300 Gambang Pahang Malaysia Earth Resources & Sustainability Centre Universiti Malaysia Pahang Lebuhraya Tun Razak Gambang Pahang 26300 Malaysia

Various procurement methods are employed in the construction industry, with each having varying success rates. The popularity of design and build (D-B) method has been increasing worldwide because its distinctive features of integrating design and construction have successfully addressed the problems inherent in the traditional design-bid-build (D-B-B) method. Previous research efforts in Malaysia have been focused on establishing a D-B strategy, including its challenges and risks and defining a broader scope for implementing D-B in public projects. However, not many empirical studies have identified the D-B success factors in Malaysia's construction industry. This paper aims to determine the main factors attributing to the successful application of the D-B method for public projects in Malaysia's construction industry. Specifically, this paper answers the main research question of 'What are the success factors of the D-B project delivery method in Malaysian public-sector projects?'. To achieve that objective, this study involves interviewing industry practitioners that have direct hands-on experience in managing D-B public sector projects in Malaysia. The interview data are analyzed to identify the D-B success factors in construction projects. The findings suggest that the underlying factors for successful D-B public project include client capabilities, competency of the construction leader, competency of the consultant team, organizational behavior, and effective project management system. The success factors in each underlying categories are discussed in the paper. This paper contributes a better understanding of the D-B project success factors in Malaysia's construction industry.

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Structural Effects of Reinforced Concrete Beam Due to Corrosion 1

Structural Effects of Reinforced Concrete Beam Due to Corros...

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1st International Conference on civil and Environmental engineering, CENVIRON 2017

作者： Mohd Noh, Hamidun Idris, Nur'Ain Md Noor, Nurazuwa Sarpin, Norliana Zainal, Rozlin Kasim, Narimah Department of Construction Management Faculty of Technology Management and Business Universiti Tun Hussein Onn Malaysia Batu Pahat Johor86400 Malaysia Department of Structure and Material Faculty of Civil Engineering and Environment Universiti Tun Hussein Onn Malaysia Batu Pahat Johor86400 Malaysia

Corrosion of steel in reinforced concrete is one of the main issues among construction stakeholders. The main consequences of steel corrosion include loss of cross section of steel area, generation of expansive pressure which caused cracking of concrete, spalling and delaminating of the concrete cover. Thus, it reduces the bond strength between the steel reinforcing bar and concrete, and deteriorating the strength of the structure. The objective of this study is to investigate the structural effects of corrosion damage on the performance of reinforced concrete beam. A series of corroded reinforced concrete beam with a corrosion rate of 0%, 20% and 40% of rebar corrosion is used in parametric study to assess the influence of different level of corrosion rate to the structural performance. As a result, the used of interface element in the finite element modelling predicted the worst case of corrosion analysis since cracks is induced and generate at this surface. On the other hand, a positive linear relationship was sketched between the increase of expansive pressure and the corrosion rate. Meanwhile, the gradient of the graph is decreased with the increase of steel bar diameter. Furthermore, the analysis shows that there is a significant effect on the load bearing capacity of the structure where the higher corrosion rate generates a higher stress concentration at the mid span of the beam. This study could predict the residual strength of reinforced concrete beam under the corrosion using the finite element analysis. The experimental validation is needed on the next stage to investigate the quantitative relation between the corrosion rate and its influence on the mechanical properties. © The Authors, published by EDP Sciences, 2018.

关键词： Corrosion rate

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Nano-structured alkaline aluminosilicate binder by carbonate mineral addition 16th

Nano-structured alkaline aluminosilicate binder by carbonate...

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16th International Conference Silicate Binders, ICBM 2017

作者： Bodnarova, L. Guzii, S. Hela, R. Krivenko, P. Vozniuk, G. Brno University of Technology Faculty of Civil Engineering Veveři 331/95 Brno60200 Czech Republic V.D. Glukhovsky Scientific Research Institute for Binders and Materials Kyiv National University of Construction and Architecture Povitroflotskii Prospect 31 Kyiv03037 Ukraine

ISBN: (纸本)9783035713480

The influence of CaCO3 on nano-structured, flowability and plastic strength of alkali activated alumonosilicate binders based on metakaolin for the range of oxide ratios in a structural formula of the Na2O∙Al2O3∙(2.5-4.5)SiO2∙(12-17)H2O + (5-15%)CaCO3 system was studied. The results of the study showed that the ratios of SiO2/Al2O3 – 3.8, H2O/Al2O3 – 13.75, and content of CaCO3 of 5% by mass were the most optimal ones from the point of view of meeting requirements for these binders to be used as base in protective coatings. The results of the study showed that process flowability of the binder with optimal ratios of oxides and 5 % by mass of additive 2 hours after preparation was by 5.4% lower, being by 5 times lower than that of the binder without the additive (CaCO3). The binder containing 5% CaCO3 by mass during 2 hours after preparation exhibited the same plastic strength (37 Pa), whereas this value of the binder without CaCO3 has increased, in average by 5.5 times, affecting negatively shelf life of this binder to be used as base in protective coatings. A conclusion was made that the addition of CaCO3 intensified the nano-structured formation processes in the direction of formation of Na-Ca zeolite-like phases;shortening time required the cement stone to gain water resistance in normal conditions. © 2018 Trans Tech Publications, Switzerland.

关键词： Calcium carbonate

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Structural features of high density polyethylene steel-plastic tenon geogrid

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Chemical engineering Transactions 2018年 66卷 73-78页

作者： Qiu, Cunjia Wang, Shuang College of Environment and Civil Engineering Chengdu University of Technology Chengdu610059 China Southwest Branch of China Airport Construction Group Corporation Chengdu610202 China

By attaching the tenon design to the high-density polyethylene (HDPE) steel-plastic composite geogrid, one new type of geogrid structure named steel-plastic tenon geogrid is designed, which can improve the anti-extraction stability of the grid, further improve the stability of rock and soil, reduce the number of grids, and save project investment. Therefore, it is very important to study and master the structural features of the tenon geogrid in engineering applications. Through a large number of studies about laboratory pull-out tests, the author applied related software to numerically simulate the structural features of the tenon geogrid, and then obtained the relative rule between the tenon thickness, the tenon side length, the mesh size of the grid, and the geogrid-soil interface parameters. This is of great significance to the design and application of the steel-plastictenon geogrid. Copyright © 2018, AIDIC Servizi S.r.l.

关键词： High density polyethylenes

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Laboratory Performance Evaluation of Co-Polymer Based Dust Suppressant Mixed with Poorly Sand

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IOP Conference Series: Materials Science and engineering 2019年第5期603卷

作者： Ziyan Wu Chun-Hsing Ho Junxin Huang Dept. of Civil and Environmental Engineering Stanford University USA Dept. of Civil Engineering Construction Management & Environmental Engineering Northern Arizona University USA Hunan Institute of Technology Hengyang PRC

Fugitive dust, generated along unpaved roads or uncovered construction sites, defined as a type of atmospheric matter (PM), is considered as a major source of air pollution in metropolitan areas. Fugitive dust can potentially cause respiratory illness and lung damage for humans, and even lead to premature death in sensitive individuals. Aiming to reduce the fugitive dust emission on unpaved roads, scientists did various lab experiences to analyse the performance of different types of dust suppressants mixed with different soils. In our previous papers, we evaluated the co-polymer-based dust suppressant (CPS) mixed with loamy sand (soils are from Sedona, Arizona) and silty clay (SP-SC) (soils are from Flagstaff, Arizona). The objective of this paper is to analyse the efficiency of fugitive dust reduction and present the quantitative laboratory evaluation of CPS mixed with poorly sand (SP). The soils were sampled from Page, Arizona. Soil classification is based on United Soil Classification System (USCS). Four concentrations of CPS (0%, 1%, 3%, and 5% by weight) were diluted and mixed with soil samples to prepared soil specimens. A series of laboratory experiences were performed on the soil specimens including moisture retention test, surface strength test, dynamic rolling test, and scanning electron microscopy (SEM) imaging. The laboratory results show that the higher the concentration of CPS is, the better CPS performs, and CPS with 5% concentration by weight controls the dust emissions better as compared with the other three concentrations, provided the results from the moisture retention rate, surface strength, dynamic rolling resistance, and interlock/cohesion effect in SEM images are promising.

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Evaluation of a Pulse Width Modulated Bypass Nozzle for the Development of a Variable Load Residential Oil Burner

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engineering（科研） 2018年第10期10卷 643-654页

作者： Mebougna L. Drabo Narinder K. Tutu Thomas Butcher George Wei Rebecca Trojanowski Department of Mechanical & Civil Engineering and Construction Management Alabama A & M University Normal AL USA Sustainable Energy Technology Department Brookhaven National Laboratory Upton NY USA

Due to the need for energy conservation in buildings and the simultaneous benefit of cost savings, the development of a low firing rate load modulating residential oil burner is very desirable. One of the two main requirements of such a burner is the development of a burner nozzle that is able to maintain the particle size distribution of the fuel spray in the desirable (small) size range for efficient and stable combustion. The other being the ability to vary the air flow rate and air distribution around the fuel nozzle in the burner for optimal combustion at the current fuel firing rate. In this paper, which deals with the first requirement, we show that by using pulse width modulation in the bypass channel of a commercial off-the-shelf bypass nozzle, this objective can be met. Here we present results of spray patterns and particle size distribution for a range of fuel firing rates. The results show that a desirable fuel spray pattern can be maintained over a fuel firing rate turndown ratio (Maximum Fuel Flow Rate/Minimum Fuel Flow Rate) of 3.7. Thus here we successfully demonstrate the ability to electronically vary the fuel firing rate by more than a factor of 3 while simultaneously maintaining good atomization.

关键词： Residential Oil Burner Variable Load Pulse Width Modulated Burner Nozzle Bypass Nozzle Droplet Spray Size Distribution Variable Fuel Firing Rate

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Thermal Unequilibrium of PdSn Intermetallic Nanocatalysts: From In Situ Tailored Synthesis to Unexpected Hydrogenation Selectivity

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Angewandte Chemie 2021年第33期133卷

作者： Minda Chen Yu Yan Mebatsion Gebre Claudio Ordonez Prof. Fudong Liu Dr. Long Qi Andrew Lamkins Dr. Dapeng Jing Kevin Dolge Biying Zhang Patrick Heintz Prof. Daniel P. Shoemaker Prof. Bin Wang Prof. Wenyu Huang Department of Chemistry Iowa State University Ames IA 50011 USA School of Chemical Biological and Materials Engineering The University of Oklahoma Norman OK 73019 USA Department of Materials Science and Engineering University of Illinois Urbana-Champaign Urbana IL 61801 USA Department of Civil Environmental and Construction Engineering Catalysis Cluster for Renewable Energy and Chemical Transformations (REACT) NanoScience Technology Center (NSTC) University of Central Florida Orlando FL 32816 USA Ames Laboratory U.S. Department of Energy Ames IA 50011 USA Materials Analysis and Research Laboratory Iowa State University Ames IA 50011 USA

Effective control on chemoselectivity in the catalytic hydrogenation of C=O over C=C bonds is uncommon with Pd-based catalysts because of the favored adsorption of C=C bonds on Pd surface. Here we report a unique orthorhombic PdSn intermetallic phase with unprecedented chemoselectivity toward C=O hydrogenation. We observed the formation and metastability of this PdSn phase in situ. During a natural cooling process, the PdSn nanoparticles readily revert to the favored Pd 3 Sn 2 phase. Instead, using a thermal quenching method, we prepared a pure-phase PdSn nanocatalyst. PdSn shows an >96 % selectivity toward hydrogenating C=O bonds of various α,β-unsaturated aldehydes, highest in reported Pd-based catalysts. Further study suggests that efficient quenching prevents the reversion from PdSn- to Pd 3 Sn 2 -structured surface, the key to the desired catalytic performance. Density functional theory calculations and analysis of reaction kinetics provide an explanation for the observed high selectivity.

关键词： heterogeneous catalysis intermetallic phases metastable compounds nanoparticles α,β-unsaturated aldehydes

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