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Silica fume as a surrogate filler in asphalt concrete mixtures: Laboratory investigation and a machine learning-based prediction

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AIP Conference Proceedings 2023年第1期2928卷

作者： Nitin Tiwari Fabio Rondinella Neelima Satyam Nicola Baldo Department of Civil Engineering Indian Institute of Technology Indore India. Polytechnic Department of Engineering and Architecture (DPIA) University of Udine Via del Cotonificio 114 33100 Udine Italy.

Transport infrastructure is a key asset in the global development of a society. Its improvement, both from the technologies and materials point of view, is a precondition to achieve sustainable and resilient progress. Under these conditions, it is necessary to investigate the feasibility of using waste materials (also called marginal materials) into a pavement mix composition in order to accomplish two main goals: adding useful life to a material that otherwise would be just a waste and saving on virgin materials supply. The presented paper aims at investigating the feasibility of using industrial waste silica fume (SF) as a surrogate filler instead of Ordinary Portland Cement (OPC). Mixtures were produced with different percentages of SF and OPC and their performance was investigated by using the results of Marshall and Indirect Tensile Strength (ITS) tests. Laboratory testing requires not only highly qualified technicians but also multiple samples in order to define functional relationships between the variables involved. In this regard, soft-computing techniques can be useful in reducing this workload and the resulting costs by identifying the aforementioned relationships by means of artificial intelligence. Therefore, the experimental data collected have been processed using Shallow Neural Networks (SNNs) that provided predictive models of the mixtures’ mechanical and volumetric parameters. Resampling and synthetic data generation techniques successfully addressed the difficulties caused by the relatively small dataset size. Results showed that the use of SF resulted in mixture performance comparable to that achieved by mixtures produced using OPC, occasionally even better. In addition, the proposed neural model performed remarkably well and thus could be used in the asphalt mixture optimization without the need for additional laboratory tests.

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Discontinuous CFRP-jacketing of masonry columns 6th

Discontinuous CFRP-jacketing of masonry columns

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6th International Conference on Mechanics of Masonry Structures Strengthened with Composite Materials, MuRiCo6 2019

作者： Lerna, Michela Micelli, Francesco Cascardi, Alessio Aiello, Maria Antonietta Department of Civil Engineering and Architecture Polytechnic of Bari Bari Italy Department of Innovation Engineering University of Salento Lecce Italy

ISBN: (纸本)9783035715651

Existing masonry columns are often susceptible to cracking due to overloading. Moreover, their fragility under earthquakes’ forces is of particular concern in seismic-prone regions. In order to mitigate these structural deficiencies, Fiber Reinforced Polymers (FRPs) are commonly used for external confinement. Full-jacketing, by means of FRP-wrapping is recognized to be very effective in improving the load bearing capacity and the ductility of masonry columns. Unfortunately, long-term effects seem to be detrimental for the masonry core, since its breathability is obstructed by the polymeric resin. Thus, a discontinuous application of the FRP-confinement appears to be more indicated in stone-masonry columns, allowing the humidity cycles to recur. On the other hand, the discontinuous wrapping negatively affects the confinement effectiveness, since both confined and unconfined masonry regions participate in the bearing capacity. In this sense, the present research is aimed to study the discontinuous confinement of half-scale masonry columns by means of Carbon-FRP strips. Unconfined and confined specimens were tested under uniaxial compression. The CFRP-confinement was studied by investigating the lateral strain in the confined and unconfined portions of the specimens. The results are reported and discussed in the paper in terms of failure modes, axial stress-strain and axial stress versus lateral strain relationships. The outcomes are reasonably convenient for a proper analytical interpretation of the phenomenon. © 2019 Trans Tech Publications Ltd, Switzerland.

关键词： Stress-strain curves

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Output Prediction of waste concrete based on GM (1, 1) 5

Output Prediction of waste concrete based on GM (1, 1)

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2020 5th International Conference on Minerals Source, Geotechnology and Civil engineering, MSGCE 2020

作者： Yin, Jian Du, Ruoxi Ma, Xinchen Zhou, Zihang Zhang, Yuxuan Luo, Wenjie School of Civil Engineering Henan Polytechnic University Henan454003 China School of Architecture and Transportation Engineering Guilin University of Electronic Technology Guangxi541004 China Department of Architecture and Civil Engineering City University of Hong Kong 999077 Hong Kong School of Electrical and Electronic Engineering Hubei University of Technology Hubei430068 China College of Agriculture Yanbian University Jilin133000 China

In order to promote efficient use of waste concrete in Chongqing, the building area estimation method is employed to estimate the waste concrete output from 2012 to 2018, and the gray model is used to predict the waste concrete output from 2019 to 2023. By Matlab programming, the waste concrete output in Chongqing will reach 3181.14t in 2023, which is 1.44 times that in 2012. The results show that the gray model can accurately forecast the output of waste concrete in Chongqing in the short and medium term. © Published under licence by IOP Publishing Ltd.

关键词： Forecasting

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Correlation and Causality between the Built Environment and Traffic Congestion: A Case Study in New York City

SSRN

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SSRN 2024年

作者： Huan, Weihua Huang, Wei Li, Songnian Liu, Xintao Wu, Hangbin Diao, Mi Li, Hao Grinberger, A. Yair Liu, Haobing Liu, Chun College of Surveying and Geo-informatics Tongji University Shanghai200092 China Department of Civil Engineering Toronto Metropolitan University TorontoM5B 2K3 Canada Department of Land Surveying and Geo-Informatics The Hong Kong Polytechnic University Kowloon Hong Kong College of Architecture and Urban Planning Tongji University Shanghai200092 China Department of Aerospace and Geodesy Professorship for Big Geospatial Data Management Technical University of Munich Munich80333 Germany Department of Geography Hebrew University of Jerusalem Israel The Key Laboratory of Road and Traffic Engineering Ministry of Education Tongji University Shanghai200092 China Urban Mobility Institute Tongji University Shanghai200092 China

The built environment’s impact on traffic congestion has been a matter of ongoing discussion. Despite the emphasis on their correlation, a comprehensive understanding of the underlying mechanisms for traffic congestion remains elusive. This study presents a systematic analysis of the correlation and causality between the built environment and traffic congestion in New York City (NYC), the United States. Utilizing road segment statistical level data, we employed the ordinary least squares regression to and five causal inference models, namely, Granger causality, structural equation model, causal forest, causal impact, and convergent cross mapping to explore the underlying mechanisms. Then, based on the correlation and causality findings, the causes behind the perpetually congested road segments are further uncovered by mantel test. The results reveal that: (1) out of the 31 selected built environment factors, 19 significantly affect traffic congestion, 11 of which are identified as causes;(2) road design and the distance from transit hubs to congested roads are actually the primary causes of traffic congestion in NYC;(3) perpetually congested roads in NYC can be mainly clustered into two types exhibiting four spatiotemporal congestion patterns, with distance and destination accessibility being the most robust causes. © 2024, The Authors. All rights reserved.

关键词： Traffic congestion

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Integration and Scale in the Context of Industry 4.0: The Evolving Shapes of Manufacturing Value Chains

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IEEE engineering Management Review 2019年第1期47卷 45-51页

作者： Culot, Giovanna Orzes, Guido Sartor, Marco Polytechnic Department of Engineering and Architecture University of Udine Udine33100 Italy Faculty of Science and Technology Free University of Bozen-Bolzano Bolzano39100 Italy

The historical evolution of manufacturing value chains (VCs) has evolved in parallel with the opportunities offered by automation and communication technologies. Since the mid-1980s, advances in telecommunications simplified the coordination of production and related activities, resulting in organizational specialization on single VC activities, while being geographically dispersed. A new wave of innovation is impacting business and society today;the Industry 4.0. The impact on VC configuration is not yet clear. Some trajectories are taking shape. This paper focuses on the potential for Industry 4.0 for integration-activities to internalize or externalize-and scale advantages. Using an extensive literature review of academic and industry studies, complemented with insights gathered through expert workshops with managers and entrepreneurs, we present a set of five possible future trajectories supported by some practical examples. © 1973-2011 IEEE.

关键词： Industry 4.0

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Numerical Modelling and Quantification of Coastal Urban Compound Flooding

SSRN

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SSRN 2023年

作者： Yuan, Jiao Zheng, Feifei Duan, Huan-Feng Deng, Zhengzhi Kapelan, Zoran Savic, Dragan Shao, Tan Huang, Wei-Min Zhao, Tongtiegang Chen, Xiaohong College of Civil Engineering and Architecture Zhejiang University Hangzhou310058 China Department of Civil and Environmental Engineering The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong Ocean College Zhejiang University Zhoushan316000 China Delft University of Technology Department of Water Management Delft Netherlands KWR Water Research Institute Nieuwegein Netherlands University of Exeter Exeter United Kingdom Faculty of Civil Engineering University of Belgrade Serbia Hydrological Measurement & Report Center at Zhuhai City Guangdong Hydrological Bureau Zhuhai519000 China Center for Water Resources and Environment School of Civil Engineering Sun Yatsen University Guangzhou510275 China

Low-lying coastal cities are vulnerable to compound floods caused by many factors including river flows, tides and local rainfall. Many previous studies focus on the impacts of rainfall and tidal levels (two driving factors) on estuaries or areas near the main single river, while research about the three influencing factors on the floods for complex urban river networks remain relatively scarce. This paper proposes a framework to simulate the coastal compound flooding process, with a series of scenarios designed to explore the main flooding drivers and their worst possible combination. The approach is used to quantify the induced flooding consequences, in which a two-dimensional model is employed to conduct a case study for a city with complex river networks. The Qianshan River basin in Zhuhai City, located in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) of China is used as the case study. Application results show that: (i) the occurrence and properties of flooding in this coastal area are jointly affected by upstream river flows, downstream tidal levels and local rainfall intensity with different contribution levels, (ii) compared to tidal levels, local rainfall intensity has a larger impact on the flooding levels of the study area, and (iii) the worst scenario where a 50-year return period upstream river flow co-occurring with high tide and a 100-year return period rainfall can produce a flooding area up to 50 km2 for the study region, with an average of 1.3 m submergence depth. The proposed framework with its findings offers an in-depth understanding and quantification of coastal urban flood characteristics within the GBA of China. © 2023, The Authors. All rights reserved.

关键词： Rain

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Upcycling red mud into high-strength high-ductility Engineered Geopolymer Composites (EGC): Toward superior performance and sustainability

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Composites Part B: engineering 2025年 305卷

作者： Ling-Yu Xu Jian-Cong Lao Lan-Ping Qian Dan-Dan Shi Jirong Lan Tian-Yu Xie Dongshuai Hou Bo-Tao Huang Institute of Advanced Engineering Structures Zhejiang University Hangzhou China Department of Civil and Environmental Engineering The Hong Kong Polytechnic University Hong Kong China Department of Civil Engineering The University of Hong Kong Hong Kong China Faculty of Architecture Civil and Transportation Engineering Beijing University of Technology Beijing China Department of Architecture and Civil Engineering City University of Hong Kong Hong Kong China School of Civil Engineering Southeast University Nanjing China Department of Civil Engineering Qingdao University of Technology Qingdao China

In this study, red mud (RM) was successfully adopted to produce high-strength high-ductility Engineered Geopolymer Composites (EGC). EGC with a high RM content of 50% achieved a compressive strength over 100 MPa and a tensile strain capacity over 5%. The influence of RM on the mechanical performances, reaction mechanisms, and environmental impacts of EGC was comprehensively investigated. Results revealed that the incorporation of RM would improve the reaction degree of precursors, densify the microstructures, and enhance the compressive strengths. Although RM incorporation would to some extent impair the tensile performances of EGC, the crack width could be effectively narrowed under a high RM content of 50%. Finally, the excellent sustainability and market potential of RM-incorporated EGC were demonstrated from environmental and cost analyses. The findings could help promote the RM upcycling technology and facilitate the development and engineering applications of this novel geopolymer composite for sustainable construction.

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A Dual-Phase Model for Predicting the Moisture Uptake in Glass Fiber-Reinforced Polymer Bars

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engineering 2025年

作者： Zhi-Hao Hao Jian-Guo Dai Jian-Fei Chen Department of Ocean Science and Engineering Southern University of Science and Technology Shenzhen Guangdong 518055 China Department of Civil and Environmental Engineering The Hong Kong Polytechnic University Hong Kong 999077 China Department of Civil Engineering Tsinghua University Beijing 100084 China Department of Architecture and Civil Engineering City University of Hong Kong Hong Kong 999077 China

Ensuring the long-term durability of glass fiber-reinforced polymer (GFRP) bars poses a significant challenge in practical applications, particularly in marine environments. Moisture absorption by GFRP bars causes hydrolysis and plasticization of the polymer matrix, resulting in a decline in both their stiffness and strength. Furthermore, the penetration of detrimental ions (e.g., OH–) with moisture accelerates the degradation of GFRP bars. Therefore, clarifying the moisture absorption behavior of GFRP bars is crucial for investigating their durability. Previous studies have indicated that the initial moisture absorption in GFRP bars conforms to the Fickian model. However, with prolonged exposure, anomalous diffusion behavior emerges, characterized as non-Fickian diffusion. This paper reviews existing models for non-Fickian diffusion, highlighting their shortcomings. Gravimetric experiments were then conducted on GFRP bars with diameters of 6, 10, and 14 mm, immersed in portable water at temperatures approximately 23, 40, and 60 ℃. Based on the test results and underlying mechanisms, an improved model, named the Weibull relaxation (WR) model, was proposed and validated using the particle swarm optimization (PSO) algorithm for regression analysis. The new model not only exhibits better agreement with the test results but also incorporates fitting parameters with clear physical interpretations. Its distinct advantage over existing models is that it is able to more realistically capture the mechanisms governing the moisture absorption of GFRP bars.

关键词： Glass fiber-reinforced polymer (GFRP) bar Fickian model Relaxation Particle swarm optimization (PSO) Moisture absorption Durability parameters Chloride diffusion coefficient Data set

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Blockchain-enabled cash flow management system in offsite construction projects

Results in Engineering

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Results in engineering 2025年 27卷

作者： Mohamed Assaf Tarek Zayed Mohamed Hussein Ghasan Alfalah PhD student Department of Civil & Environmental Engineering University of Alberta Edmonton T6G 2R3 AB Canada Professor Department of Building and Real Estate The Hong Kong Polytechnic University Hong Kong SAR PhD Graduate Department of Building and Real Estate The Hong Kong Polytechnic University Hong Kong SAR Lecturer Department of Civil Engineering Faculty of Engineering Assiut University Assiut 71511 Egypt Associate Professor Department of Architecture and Building Science College of Architecture and Planning King Saud University Riyadh 145111 Saudi Arabia

Offsite construction (OSC) technology provides substantial merits over traditional methods, such as shorter schedules and reduced waste. Nonetheless, its implementation is constantly hindered by financial barriers. Existing studies on overcoming OSC financial barriers were limited to cost estimation and factorial analysis. At the same time, the need for a cash flow system to automate progress payments and integrate OSC participants persists. This paper contributes to the body of knowledge by proposing a cash flow management system for OSC projects based on blockchain and building information modeling technologies. The proposed system supports many features, including automated financial transactions, flexibility in applying various procurement systems, facilitation of possible claims (i.e., extension of time and liquidated damages), and secure and immutable recording of all transactions. A proof-of-concept method is used to showcase the applicability of the proposed system by developing five case scenarios. The findings prove the system's capabilities to provide a secure platform for financial transactions among OSC participants without third-party involvement.

关键词： Offsite construction Blockchain Smart contracts Hyperledger fabric Proof of concept

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Vanillin-based photoactive materials: A sustainable approach to antimicrobial solutions

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Journal of Photochemistry and Photobiology A: Chemistry 2025年 468卷

作者： Gover, Elisabetta Rondinella, Alfredo Marino, Marilena Brovedani, Asja Tavani, Alessandra Lopriore, Marco Alongi, Marilisa Manzocco, Lara Fedrizzi, Lorenzo Goi, Daniele Strazzolini, Paolo Comuzzi, Clara Polytechnic Department of Engineering and Architecture University of Udine Via del Scienze 206 Udine33100 Italy Department of Agricultural Food Environment and Animal Sciences University of Udine Via delle Scienze 206 Udine33100 Italy

Bacterial infections result in millions of fatalities each year globally, an issue exacerbated by the alarming rise in antibiotic-resistant pathogens. To combat the spread of these microorganisms, photodynamic inactivation strategies can be employed, which kill microbes by generating reactive oxygen species (ROS) without leading to the development of resistance phenomena. Considering the challenges posed by microbial threats and the need for environmental sustainability, a polyimine matrix named VALPOL (VP) was developed using a lignin waste intermediate, vanillin. This matrix was doped with the photosensitizer (PS) 5,10,15,20-tetrakis(4-methylphenyl)-21H,23H-porphyrin (4MeP) to yield two photoactive materials containing 5 % (VP-5-F) and 10 % w/w (VP-10-F) of PS. The VP-based films underwent comprehensive characterization through FTIR spectrophotometry, DSC analysis, and SEM microscopy. Water absorption capacity, diffusion coefficient, film regeneration, and antimicrobial capabilities were also assessed. Following exposure to a blue LED lamp, the VP-doped matrices demonstrated significant antimicrobial efficacy, achieving up to a 3-Log reduction in Staphylococcus aureus viability. This effect was attributed to the material's ability to generate singlet oxygen via a photodynamic mechanism. Notably, the photokilling effect was enhanced with the reuse of the films, likely due to the morphological changes observed through SEM. The materials exhibited stability, resistance to operational conditions, and ease of molding, combined with light-activated antimicrobial properties, indicating their potential for diverse applications. This research highlights the promise of photoactive vanillin-based films as antimicrobial materials, aligning with sustainable principles in both the photodynamic disinfection method and the material itself. © 2025 The Author(s)

关键词： Staphylococcus aureus

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