The article presents methods of using modern technologies to conduct the research on working time in construction. At the beginning examples of GPS, DS systems, and use of drones in construction have been presented. N...
The article presents methods of using modern technologies to conduct the research on working time in construction. At the beginning examples of GPS, DS systems, and use of drones in construction have been presented. Next, the theoretical bases identifying factors affecting the performance of construction workers have been presented. They provide the basis for the presented methodology of conducted research. An RFID radio system has been shown, together with other devices that allow to locate the construction workers and send information about their physical condition. In the described system the data is stored on an external server and there is the possibility of working on them in the cloud. The presented research is an innovative and globally unique approach to the performance of construction workers.
The article draws close attention to the need to consider the impact of risk on the value of estimated life cycle cost of a building object. The main goal of the proposed approach to the risk assessment is to answer t...
The article draws close attention to the need to consider the impact of risk on the value of estimated life cycle cost of a building object. The main goal of the proposed approach to the risk assessment is to answer the question of consideration of the impact of the identified risk factor for a given component of the life cycle cost of a building object. This model of the reasoning mechanism is built based on fuzzy interpretation of two distinctive input variables for risk, ie. the probability and effect of a unwanted phenomenon. Due to the small number of input variables and thus the minimal possible number of reasoning rules, to the construction of the model used the fuzzy reasoning model of Mamdani.
This paper presents a validation of a recently developed joint input-state estimation algorithm for force identification and response estimation in structural dynamics, using data obtained from in situ experiments on ...
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(纸本)9781510827936
This paper presents a validation of a recently developed joint input-state estimation algorithm for force identification and response estimation in structural dynamics, using data obtained from in situ experiments on a footbridge. First, the algorithm is used to identify two impact forces applied to the bridge deck. Next, the algorithm is used to extrapolate measured accelerations due to wind loading to unmeasured locations in the structure. The dynamic model of the footbridge used in the system inversion is obtained from a detailed finite element model, that is calibrated using a set of experimental modal characteristics. The quality of the estimated forces and accelerations is assessed by comparison with the corresponding measured quantities. In both cases, a very good overall agreement is obtained.
Coal power plants represent the large source of environmental pollution in soils, ground and surface water by leaching out toxic compounds from open landfilled and impounded coal combustion residuals (CCR) such as fly...
Coal power plants represent the large source of environmental pollution in soils, ground and surface water by leaching out toxic compounds from open landfilled and impounded coal combustion residuals (CCR) such as fly ash. The use of fly ash as a main component in geopolymer binder (GB) systems is one of the effective methods of CCR beneficial utilization. The toxicity assessment as well as leachability of harden geopolymers were tested in aqueous media where oat seeds were used as affected test objects. Bio-resistance of the developed geopolymers was evaluated by the resistance to mold fungi growth. The developed geopolymers demonstrated a very low toxicity and leachability to the biota based on the low effect to germinating ability and growth retardation of the exposed oat seeds. Therefore, the studied fly ash products were proved to be environmentally safe when used in GB systems. The absence of fungi growth observed on the surface of geopolymer samples demonstrates high bio-resistance.
The research deals with reconstruction projects investigation by applying statistical analysis and multiple criteria decision-making method, also research on application of Building Information Modelling (BIM) methodo...
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The research deals with reconstruction projects investigation by applying statistical analysis and multiple criteria decision-making method, also research on application of Building Information Modelling (BIM) methodology for reconstruction projects. The implementation of reconstruction projects face a lot of problems, and the list of problems is identified when analyzing Lithuanian case studies. The analysis shows that it is necessary to monitor design, construction and maintenance stages both for quality control and information management during the whole project life cycle. According to suggested problem recognition methodology, the list of problems is analyzed in terms of occurrence in the projects and influence to the project. The complex solution is based on estimated problems significance as a result of statistical survey and expert survey by applying Analytic Hierarchy Process (AHP) methodology. Possible BIM uses for reconstruction projects are suggested to prevent the identified problems.
Non-Value Adding Activities That Are Otherwise Called 'Waste' In The Lean Terms Have Continue To Hinder Efficient Project Delivery In The construction Industry. As Such, The Types Of Waste And Their Impact Are...
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Non-Value Adding Activities That Are Otherwise Called 'Waste' In The Lean Terms Have Continue To Hinder Efficient Project Delivery In The construction Industry. As Such, The Types Of Waste And Their Impact Are Subject Of Many Studies. However, Much Have Not Been Done Regarding Waste In The Structural Design Process (Sdp). This Paper Reports On An On-Going Action Research Study On Waste In The Sdp. To Understand The Waste Types And Their Effects, The Lean Tool, Value Stream Mapping (Vsm), Has Been Deployed In The Doctoral Study. To Make Use Of The Tool For Sdp, A Purposively Selected Sample Of Consulting Structural Engineers, Practicing In Bloemfontein Were Interviewed In 2015. After That, A Vsm Depicting The Current State Of The Sdp And The Waste In The Process Was Compiled. The Vsm Tool Was Used To Analyze And Design The Flow Of Information. Major Waste Types Include Waiting Time, Excessive Motion, Excessive Production, And Excessive Inspection. The Eradication Of These Waste Influenced The Design Of A Proposed Future State Vsm Wherein All The Identified Problems Are Adequately Addressed. The Applicability And Usefulness Of The Vsm As It Enables Structural Designers To Perceive The Various Activities That Could Be Trimmed In Each Phase Of The Sdp Is Supported By The Results Of The Study, Although The Credibility Of The Future State Vsm Is Currently Being Examined By The Consulting Engineers.
In a real cable-strut tensile structure, construction errors are inevitable. To explore the optimal construction scheme and control construction errors, this study optimized the construction scheme of a cable-strut te...
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The paper presents the results of the research into the influence of various ultra- and nanodisperse size additives on the structure and mechanical-and-physical properties of heat insulating autoclaved aerated concret...
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The paper presents the results of the research into the influence of various ultra- and nanodisperse size additives on the structure and mechanical-and-physical properties of heat insulating autoclaved aerated concrete (AAC). Research into interaction mechanisms of such additives as silica gel, high active metakaolin and multi-walled carbon nanotube dispersion (MWCNTs) with heat insulating AAC components consisted in the evaluation of the dynamics of the cellular concrete plastic strength increase of porous mixture, degree of cellular concrete blowup and comparing the strength and density of the check sample and the modified one. The studies found that the most effective method of obtaining the structural strength of AAC is by the use of the MWCNTs. They contribute to obtaining the optimum viscoplastic properties of bulk concrete and stabilizing of the pore formation process with simultaneous formation of the solid homogeneous hexagonal structure.
A number of cold work processes have been attempted to improve the fatigue performance of metallic materials. A competent indentation may have a positive effect on increasing the fatigue property of metals, and it was...
A number of cold work processes have been attempted to improve the fatigue performance of metallic materials. A competent indentation may have a positive effect on increasing the fatigue property of metals, and it was expected to strength mild steel with outstanding ductility but relatively weak strength. Indentation was introduced by a round steel indenter with a diameter of 5 mm. Fatigue crack growth behaviour and hardness distribution of both as-received specimen and specimen with indentations were studied systematically together with relevant microscope observations on fatigue-fractured surfaces. The results show that indentation could significantly improve the fatigue property of specimen because of the generation of compressive residual stress, and considerable increase the hardness near the location of indentation due to increase of material density.
In this paper the enhancement of an introductory Finite Element course in the newly established civilengineering and construction Management Department at Georgia Southern University is discussed. Typically in an Int...
In this paper the enhancement of an introductory Finite Element course in the newly established civilengineering and construction Management Department at Georgia Southern University is discussed. Typically in an Introductory Finite Element course offered in many engineering schools, a simple less elaborate FE package is used to deliver the course concepts. In the newly developed course discussed in the paper, a state-of-the-art commercial software package is planned to be utilized to further enhance the marketability of the students upon graduation. Along with this choice comes the challenge of developing suitable tutorials and examples to familiarize the students with various important tools and special features of this sophisticate package in the minimum amount of time possible. The submitted paper explores one possible strategy to accomplish this task. This course is designed for exploring the civilengineering applications focusing specifically on analysis of structural components, rather than solving problems related to other fields such as fluid mechanics or heat transfer. The planned projects in the course explore strategies in analyzing a variety of structural members such as trusses, beams, frames, as well as other solid continuums. The course is expected to complement other structural engineering related courses delivered in the curriculum such as Structural Analysis and Advanced Structural Analysis. Solutions of problems obtained in this course using the FE package can be compared and contrasted against the results from other classical methods discussed in these courses. Some of these methods include: Slope-Deflection Method, Moment Distribution Method, and Matrix Stiffness Method. These comparisons further enhance the knowledge of the students in area of structures and provide them with new perspectives. Several prepared example problems for the course are included in the paper to further illustrate the value of the project. Each of these examples is s
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