Read by QxMD icon Read

Civil engineering

A Naillon, P Joseph, M Prat
The stress generation on pore walls due to the growth of a sodium chloride crystal in a confined aqueous solution is studied from evaporation experiments in microfluidic channels in conjunction with numerical computations of crystal growth. The study indicates that the stress buildup on the pore walls is a highly transient process taking place over a very short period of time (in less than 1 s in our experiments). The analysis makes clear that what matters for the stress generation is not the maximum supersaturation at the onset of the crystal growth but the supersaturation at the interface between the solution and the crystal when the latter is about to be confined between the pore walls...
January 19, 2018: Physical Review Letters
Rebecca Napolitano, Anna Blyth, Branko Glisic
Visualization of sensor networks, data, and metadata is becoming one of the most pivotal aspects of the structural health monitoring (SHM) process. Without the ability to communicate efficiently and effectively between disparate groups working on a project, an SHM system can be underused, misunderstood, or even abandoned. For this reason, this work seeks to evaluate visualization techniques in the field, identify flaws in current practices, and devise a new method for visualizing and accessing SHM data and metadata in 3D...
January 16, 2018: Sensors
Janek Reinik, Natalya Irha, Arina Koroljova, Tõnis Meriste
Oil shale ash (OSA) was used for road construction in a pristine swamp area in East-Estonia during 2013-2014. OSA was used as a binder both in mass stabilization of soft peat soil and in the upper layer. Use of OSA in civil engineering always raises questions about the environmental safety of such activities. Post-construction environmental monitoring of the pilot section was carried out in 2014 and 2015. The monitoring program involved surface water and soil sampling campaigns. Samples were analyzed for selected constituents and parameters of environmental concern...
January 5, 2018: Environmental Monitoring and Assessment
Adela P Galvín, Jesús Ayuso, Auxi Barbudo, Manuel Cabrera, Antonio López-Uceda, Julia Rosales
In general terms, plant managers of sites producing construction wastes assess materials according to concise, legally recommended leaching tests that do not consider the compaction stage of the materials when they are applied on-site. Thus, the tests do not account for the real on-site physical conditions of the recycled aggregates used in civil works (e.g., roads or embankments). This leads to errors in estimating the pollutant potential of these materials. For that reason, in the present research, an experimental procedure is designed as a leaching test for construction materials under compaction...
December 27, 2017: Environmental Science and Pollution Research International
Numa Joy Bertola, Maria Papadopoulou, Didier Vernay, Ian F C Smith
Assessing ageing infrastructure is a critical challenge for civil engineers due to the difficulty in the estimation and integration of uncertainties in structural models. Field measurements are increasingly used to improve knowledge of the real behavior of a structure; this activity is called structural identification. Error-domain model falsification (EDMF) is an easy-to-use model-based structural-identification methodology which robustly accommodates systematic uncertainties originating from sources such as boundary conditions, numerical modelling and model fidelity, as well as aleatory uncertainties from sources such as measurement error and material parameter-value estimations...
December 14, 2017: Sensors
Meng Sun, Yide Wang, Cédric Le Bastard, Jingjing Pan, Yuehua Ding
In civil engineering, Time Delay Estimation (TDE) is one of the most important tasks for the media structure and quality evaluation. In this paper, the MUSIC algorithm is applied to estimate the time delay. In practice, the backscattered echoes are highly correlated (even coherent). In order to apply the MUSIC algorithm, an adaptation of signal subspace smoothing is proposed to decorrelate the correlation between echoes. Unlike the conventional sub-band averaging techniques, we propose to directly use the signal subspace, which can take full advantage of the signal subspace and reduce the influence of noise...
December 10, 2017: Sensors
Georgios Kazakis, Ioannis Kanellopoulos, Stefanos Sotiropoulos, Nikos D Lagaros
Construction industry has a major impact on the environment that we spend most of our life. Therefore, it is important that the outcome of architectural intuition performs well and complies with the design requirements. Architects usually describe as "optimal design" their choice among a rather limited set of design alternatives, dictated by their experience and intuition. However, modern design of structures requires accounting for a great number of criteria derived from multiple disciplines, often of conflicting nature...
October 2017: Heliyon
Tao Zhang, Guojun Cai, Weihong Duan
The disposal of scrap rubber tires has induced critical environmental issue worldwide due to the rapid increase in the number of vehicles. Recycled scrap tires as a construction material in civil engineering have significant environmental benefits from a waste management perspective. A systematic study that deals with strength and microstructure characteristics of the rubber-sand mixtures is initiated, and mechanical response of the mixtures is discussed in this investigation. Experiments were conducted to evaluate the effects of rubber fraction on the basic properties including mass density (ρ), stress-strain characteristics, shear strength, and unconfined compression strength (q u) of the rubber-sand mixtures...
November 25, 2017: Environmental Science and Pollution Research International
Jean-Baptiste Legland, Yuxiang Zhang, Odile Abraham, Olivier Durand, Vincent Tournat
The field of civil engineering is in need of new methods of non-destructive testing, especially in order to prevent and monitor the serious deterioration of concrete structures. In this work, experimental results are reported on fault detection and characterization in a meter-scale concrete structure using an ultrasonic nonlinear coda wave interferometry (NCWI) method. This method entails the nonlinear mixing of strong pump waves with multiple scattered probe (coda) waves, along with analysis of the net effect using coda wave interferometry...
October 2017: Journal of the Acoustical Society of America
Xing Lu, Shuangyou Zhang, Xing Chen, Dohyeon Kwon, Chan-Gi Jeon, Zhigang Zhang, Jungwon Kim, Kebin Shi
Ultrahigh-resolution optical strain sensors provide powerful tools in various scientific and engineering fields, ranging from long-baseline interferometers to civil and aerospace industries. Here we demonstrate an ultrahigh-resolution fibre strain sensing method by directly detecting the time-of-flight (TOF) change of the optical pulse train generated from a free-running passively mode-locked laser (MLL) frequency comb. We achieved a local strain resolution of 18 pε/Hz(1/2) and 1.9 pε/Hz(1/2) at 1 Hz and 3 kHz, respectively, with large dynamic range of >154 dB at 3 kHz...
October 17, 2017: Scientific Reports
Junhwa Lee, Kyoung-Chan Lee, Soojin Cho, Sung-Han Sim
The displacement responses of a civil engineering structure can provide important information regarding structural behaviors that help in assessing safety and serviceability. A displacement measurement using conventional devices, such as the linear variable differential transformer (LVDT), is challenging owing to issues related to inconvenient sensor installation that often requires additional temporary structures. A promising alternative is offered by computer vision, which typically provides a low-cost and non-contact displacement measurement that converts the movement of an object, mostly an attached marker, in the captured images into structural displacement...
October 11, 2017: Sensors
Tianyong Jiang, Junbo Zheng, Linsheng Huo, Gangbing Song
With the development of the post-tensioning technique, prestressed concrete structures have been widely used in civil engineering. To ensure the long-term effectiveness of the prestressed tendon, the grouting quality of the tendon duct is one of the important factors. However, it is still a challenge to monitor the grouting quality of post-tensioning tendon ducts, due to the invisibility of the grouting. The authors' previous work proposed a real-time method that employed a stress wave-based active sensing approach with piezoceramic transducers to monitor the grouting compactness of a Post-Tensioning Tendon Duct (PTTD)...
September 29, 2017: Sensors
Clémence Essé, Véronique A Koffi, Abel Kouamé, Kouassi Dongo, Richard B Yapi, Honorine M Moro, Christiane A Kouakou, Marta S Palmeirim, Bassirou Bonfoh, Eliézer K N'Goran, Jürg Utzinger, Giovanna Raso
BACKGROUND: Integrated control programs, emphasizing preventive chemotherapy along with health education, can reduce the incidence of soil-transmitted helminthiasis and schistosomiasis. The aim of this study was to develop an educational animated cartoon to improve school children's awareness regarding soil-transmitted helminthiasis, diarrheal diseases, and related hygiene practices in Côte d'Ivoire. The key messages included in the cartoon were identified through prior formative research to specifically address local knowledge gaps...
September 2017: PLoS Neglected Tropical Diseases
Kamal Niaz, Faheem Maqbool, Haji Bahadar, Mohammad Abdollahi
Honey is known for its therapeutic properties from ancient civilizations but only since last few decades its mechanism has been studied on how it causes epithelial regeneration leading to wound and ulcer healing.. In the present review the health perspectives of honey, its chemical composition with special reference to flavonoids, polyphenol composition and other bioactive trace compounds used in tissue regeneration have been highlighted. Honey can inhibit carcinogenesis by moderating with molecular processes of initiation, advancement and progression stage of cancer cells, therefore it is considered a promising anti-cancer agent...
September 11, 2017: Current Drug Metabolism
Ueli M Angst, Carolina Boschmann, Matthias Wagner, Bernhard Elsener
The aging of reinforced concrete infrastructure in developed countries imposes an urgent need for methods to reliably assess the condition of these structures. Corrosion of the embedded reinforcing steel is the most frequent cause for degradation. While it is well known that the ability of a structure to withstand corrosion depends strongly on factors such as the materials used or the age, it is common practice to rely on threshold values stipulated in standards or textbooks. These threshold values for corrosion initiation (Ccrit) are independent of the actual properties of a certain structure, which clearly limits the accuracy of condition assessments and service life predictions...
August 31, 2017: Journal of Visualized Experiments: JoVE
Jaroslava Koťátková, Jan Zatloukal, Pavel Reiterman, Karel Kolář
This review article presents the current state-of-knowledge of the use of cementitious materials for radioactive waste disposal. An overview of radwaste management processes with respect to the classification of the waste type is given. The application of cementitious materials for waste disposal is divided into two main lines: i) as a matrix for direct immobilization of treated waste form; and ii) as an engineered barrier of secondary protection in the form of concrete or grout. In the first part the immobilization mechanisms of the waste by cement hydration products is briefly described and an up-to date knowledge about the performance of different cementitious materials is given, including both traditional cements and alternative binder systems...
November 2017: Journal of Environmental Radioactivity
Zhi Cao, Lei Shen, Amund N Løvik, Daniel B Müller, Gang Liu
Modern cities and societies are built fundamentally based on cement and concrete. The global cement production has risen sharply in the past decades due largely to urbanization and construction. Here we deployed a top-down dynamic material flow analysis (MFA) model to quantify the historical development of cement in-use stocks in residential, nonresidential, and civil engineering sectors of all world countries. We found that global cement production spreads unevenly among 184 countries, with China dominating the global production and consumption after the 1990s...
September 12, 2017: Environmental Science & Technology
Tarique Ahmad, Kafeel Ahmad, Mehtab Alam
Large volume of sludge is generated at the water treatment plants during the purification of surface water for potable supplies. Handling and disposal of sludge require careful attention from civic bodies, plant operators, and environmentalists. Quantification of the sludge produced at the treatment plants is important to develop suitable management strategies for its economical and environment friendly disposal. Present study deals with the quantification of sludge using empirical relation between turbidity, suspended solids, and coagulant dosing...
August 15, 2017: Environmental Monitoring and Assessment
Coleen M Carrigan
Computing is highly segregated and stratified by gender. While there is abundant scholarship investigating this problem, emerging evidence suggests that a hierarchy of value exists between the social and technical dimensions of Computer Science and Engineering (CSE) and this plays a role in the underrepresentation of women in the field. This ethnographic study of women's experiences in computing offers evidence of a systemic preference for the technical dimensions of computing over the social and a correlation between gender and social aspirations...
2017: Frontiers in Psychology
Feng Lin, Yu Dong, Xinxin Kuang, Le Lu
The strain rate effect of reinforcing steel bars is generally indispensable for modeling the dynamic responses of reinforced concrete structures in blast and impact events. A systematic experimental investigation was conducted on the strain rate behavior of reinforcing steel bar grades HPB235, HRB335, HRB400, and HRB500 which are widely used in the field of civil engineering in China. The dynamic testing was performed using a servo-hydraulic Instron VHS160/100-20 in a strain rate range from 2 to 75 s(-1). Stress-strain curves at preset strain rates were obtained...
December 15, 2016: Materials
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"