The Application of Recycled Plastic Insulation Materials in Constructions – Serbian Prospects

Plastic is one of the most popular and useful materials of modern times. However, its popularity is part of the problem: we now use about 20 times more plastic than we did 50 years ago. However, the lifespan of plastics can be optimized by reuse and recycling. As the space for landfilling is diminishing, recycling plastic has become an attractive alternative to final disposal. The main objective of this paper is to present a novel thermal insulation building material for construction engineering made from recycled plastic. Based on conducted research, it can be concluded that Serbia has a relatively good level of activity in the recycling sector. In the plastic recycling process, PET flakes are produced, from which, through further processing, polyester fibre is gained whose further use in the production of insulation material is possible. Unfortunately, there is no factory in Serbia that currently produces this kind of insulation. All further analyses are based on recycled plastic insulation materials, which are developed and commercialized on the foreign market. The paper presents the technical characteristics of these materials in relation to the classical insulating materials and analyzes the economic and other factors affecting the possibility of employing these materials in the Serbian construction industry. The analyses results are that in terms of thermal and technical characteristics, insulation materials from recycled plastic do not lag behind conventional insulation materials. In terms of environment and human health impacts, there are no negative effects. The calculation demonstrates that a building envelope, which contains recycled plastic thermal insulation material, can reach low-energy and even more passive building standards. The initial cost of investing in thermal insulation returns within the first years of the exploitation period

Standard in project management - ANSI/PMI 99-001- 2008 brief presentation

Project management has evolved over time, becoming the principal mean of dealing with change in modern organizations. Best practices have occurred as a result of business evolution and of practicing project management at a global level. Best practices and standards for project management, if followed, increase the chances of success in achieving project goals. In this article we present the need for and the advantages of using best practices in project management, which are the best practices used today and we also give a brief presentation of the mostly used best practice methodology in project management, Project Management Body of Knowledge

Prednosti primene BIM tehnologija u upravljanju projektima

Svetska građevinska industrija se nalazi u fazi inicijalnog razvoja BIM (Building Information Model/Modeling) tehnologija, metodologija i alata, kao potpuno novog pristupa projektovnju. Prednosti koje BIM, kao jedinstveni model sa svim integrisanim podacima o objektu kroz sve faze nastanka i korišćenja objekta u odnosu na tradicionalne 2D projekte pruža su brojne i veoma značajne. U ovom radu će najpre biti sažeto prikazane prednosti upotrebe BIM-a kroz faze izgradnje a zatim rezultati istraživanja značaja i isplativosti primene BIM-a za teritoriju SAD-a. U poslednjem delu će biti kratko prezentirana izvesna korišćena softverska rešenja koja, premda i sama u razvoju, razvijaju i proširuju mogućnosti operativne primene i daljeg napredovanja BIM tehnologija

Optimization of construction measures for reducing heating energy demand in residential buildings

Sektor zgradarstva je najveći pojedinačni potrošač energije. Unapređenje energetske efikasnosti u zgradarstvu jedna je od najšire promovisanih mera za smanjenje eksploatacije neobnovljivih izvora energije i ublažavanje klimatskih promena kroz smanjenje emisije ugljen-dioksida. Ultimativni cilj treba da bude povećanje efikasnosti korišćenja energije i usporavanje rasta ukupne proizvedene energije, što zasigurno dovodi do ublažavanja klimatskih promena. Predmet istraživanja u ovoj disertaciji jeste energetska efikasnost u stambenim zgradama u delu koji se odnosi na smanjenje potrebne energije za grejanje. Uže gledano, predmet istraživanja su: (1) metode za proračun i procenu toplotnih gubitaka termičkog omotača zgrade u nestacionarnim uslovima prenosa toplote; i (2) višekriterijumski modeli za izbor i ocenu energetske efikasnosti građevinskih mera kod izgradnje novih ili energetske sanacije postojećih zgrada. Cilj istraživanja je bio da se definiše model koji bi davao podršku projekt menadžeru u procesu donošenja odluke vezane za izbor optimalnog rešenja pri izgradnji novih objekata ili rekonstrukciju postojećih, pri tome sagledavajući investicionu odluku sa više aspekata imajući u vidu i zahteve velikog broja zainteresovanih strana, kako u kratkoročnom tako i u dugoročnom periodu. U cilju ostvarenja postavljenog zadatka prvo je razvijen originalan precizan matematički model koji opisuje fizički proces razmene toplote između objekta i okoline, a koji dalje predstavlja osnov za pouzdan proračun troškova u periodu eksploatacije, definisanje mogućeg termalnog komfora u objektu kao i procenu uticaja objekta na životnu sredinu. S obzirom na postavljene ciljeve istraživanja, u disertaciji su prezentovana dva rezultata: (1) razvijen je novi pristup za određivanje svih relevantnih dinamičkih termičkih veličina koje služe za procenu prenosa toplote kroz građevinske elemente netransparentnog dela fasade i ocenu toplotnog komfora u zgradama i (2) razvijen je višekriterijumski model za optimizaciju izbora građevinskih mera koji u sebi, pored energetskih, finansijskih i ekoloških parametara, sadrži i dinamičke termičke parametre kao kriterijume za ocenu toplotnog komfora u zgradama...Building sector is the largest individual energy consumer. Increasing energy efficiency of buildings is one of the most widely promoted measure for reducing exploitation of non-renewable energy sources and mitigating climate changes through carbon dioxide emission reduction. The ultimate goal should be to increase the efficiency of energy use and the slowdown in overall energy produced, which certainly leads to climate change mitigation. The subject of research in this dissertation was energy efficiency in the residential building sector, in particular, the reduction of energy demand for heating. Narrowly seen, the subject of research was: (1) methods for calculating and estimating heat losses through the building’s thermal envelope in non-stationary conditions of heat transfer and (2) multi-criteria decision-making models for evaluating the energy efficiency of building construction measures for new or existing residential buildings. The aim of the research was to define a model that will support a decision-making process that project manager passes when making an optimal decision regarding the construction of new buildings or the refurbishment of old ones, respecting a large number of stakeholder requirements that project manager must deal with and considering many aspects of the investment in the short and long term. The task was to develop an original precise mathematical model describing the physical process of heat exchange between the building and the environment, which further provides the basis for a reliable calculation of the costs related to energy consumption incurred during the exploitation phase, the assessment of the achieved thermal comfort in the building as well as the assessment of the environmental impact of the building. Having in mind the stated research objectives, two resultes have been presented in the dissertation: (1) a novel approach has been developed for the determination of all relevant dynamic thermal caracteristics used to estimate heat transfer through the opaque components of the building envelope in a dynamic regime and the assessment of thermal comfort in the building and (2) a multi-criteria decision-making model has been developed for the selection of optimal construction measures that, in addition to energy, financial and environmental parameters, implies the introduction of dynamic thermal parameters as criteria for assessing thermal comfort in buildings..

Critical risks in Serbian infrastructure projects

Infrastructure projects are usually followed by numerous standard, but also specific risks associated with project cost, schedule, quality, performance, health and safety aspects, environmental aspects, as well as with other, non‐tangible factors. They, if not timely identified, treated and controlled cause that project actual performance significantly varies from planned values. This paper presents results of a conducted infrastructure construction project risks survey for projects settled in Serbia. The survey includes evaluation of major risks in relation to infrastructure project cost and schedule performance and the analysis of usage, necessity and problems with construction Project Risk Management (PRM) practice in Serbia. Risks in the offered risk list were divided into: General Market Risks, Risks in Feasibility and Design Phase and Risk in Construction Phase and evaluated using Probability‐Impact matrix. Based on the results, the proposal is given for the development of an advance planning cost and schedule performance prediction model

CFD simulation of thermal performances of building structure with expanded polystyrene (EPS) as thermal insulation

In this paper a three dimensional (3D), Computational Fluid Dynamics (CFD) simulation for indoor air flow and heat transfer in a single room was developed. The multi-layer structure building envelop, with expanded polystyrene (EPS) as thermal insulation inside, has been included into simulation and its influence on thermal performances were analysed. The indoor air flow and temperature distribution were analysed for different thicknesses of EPS insulations and were compared to the case without insulation. The commercial software FLUENT has been used in the simulation. The air flow due to natural convection is included into the model through a buoyancy-driven flow. The realizable k- model, based on Reynolds-Averaged Navier-Stokes (RANS) equations, is used for modelling of the turbulence in air flow. The radiator model with thermal flux as input parameter is used for simulation of heating of the room. In order to resolve flow in boundary layer high resolution grid near walls and low-Reynolds number has been used. According to the presented results the thickness of thermal insulation has significant influence on the indoor air flow and the temperature distribution inside the building

Project Risk Management and BIM Application in Serbia – Survey Results

Although risk towards construction project success may occur in any of project life cycle phase, it is most important for risks to be analyzed and assessed in project development process, where Building Information Modelling (BIM) could improve Project Risk Management (PRM). Risks, if not timely identified, treated and controlled cause that project actual performance significantly varies from planned values. This paper presents results of an still ongoing infrastructure construction project risks survey for projects settled in Serbia. The survey includes: Analysis of usage, necessity and problems with construction PRM practice and BIM practice in Serbia

Multi-Objective Optimization Model for The Selection of Measures for Energy Efficient Retrofitting of Building Envelopes

Within this paper, a multi-criteria decision-making model for evaluating the energy efficiency of building construction measures for new or existing buildings will be presented. The proposed model observes the optimization process simultaneously through the four most important aspects of energy efficiency: economic aspect, energy consumption, environmental impact and indoor comfort, taking into account factors that may occur in the building environment during its operation, such as inflation and currency depreciation/appreciation. The model introduces dynamic thermal parameters of the wall that reflect a thermal accumulation of the building envelope and its ability to provide thermal comfort in time-varying atmospheric conditions in the building environment