Abstract: The using of waste materials in the construction
industry can reduce the dependence on the natural aggregates which
are going at the end to deplete. The glass waste is generated in a huge
amount which can make one of its disposals in concrete industry
effective not only as a green solution but also as an advantage to
enhance the performance of mechanical properties and durability of
concrete. This article reports the performance of concrete specimens
containing different percentages of milled glass waste as a partial
replacement of cement (Powder), when they are subject to cycles of
freezing and thawing. The tests were conducted on 75-mm cubes and
75 x 75 x 300-mm prisms. Compressive strength based on laboratory
testing and non-destructive ultrasonic pulse velocity test were
performed during the action of freezing-thawing cycles (F/T). The
results revealed that the incorporation of glass waste in concrete
mixtures is not only feasible but also showed generally better strength
and durability performance than control concrete mixture. It may be
said that the recycling of waste glass in concrete mixes is not only a
disposal way, but also it can be an exploitation in concrete industry.
Abstract: Residential buildings consume significant amounts of
energy and produce large amount of emissions and waste. However,
there is a substantial potential for energy savings in this sector which
needs to be evaluated over the life cycle of residential buildings. Life
Cycle Assessment (LCA) methodology has been employed to study
the primary energy uses and associated environmental impacts of
different phases (i.e., product, construction, use, end of life, and
beyond building life) for residential buildings. Four different
alternatives of residential buildings in Vancouver (BC, Canada) with
a 50-year lifespan have been evaluated, including High Rise
Apartment (HRA), Low Rise Apartment (LRA), Single family
Attached House (SAH), and Single family Detached House (SDH).
Life cycle performance of the buildings is evaluated for embodied
energy, embodied environmental impacts, operational energy,
operational environmental impacts, total life-cycle energy, and total
life cycle environmental impacts. Estimation of operational energy
and LCA are performed using DesignBuilder software and Athena
Impact estimator software respectively.
The study results revealed that over the life span of the buildings,
the relationship between the energy use and the environmental
impacts are identical. LRA is found to be the best alternative in terms
of embodied energy use and embodied environmental impacts; while,
HRA showed the best life-cycle performance in terms of minimum
energy use and environmental impacts. Sensitivity analysis has also
been carried out to study the influence of building service lifespan
over 50, 75, and 100 years on the relative significance of embodied
energy and total life cycle energy. The life-cycle energy requirements
for SDH are found to be a significant component among the four
types of residential buildings. The overall disclose that the primary
operations of these buildings accounts for 90% of the total life cycle
energy which far outweighs minor differences in embodied effects
between the buildings.
Abstract: Brownfields are one of the most important problems
that must be solved by today's cities. The topic of this article is
description of developing a comprehensive transformation of postindustrial
area of the former iron factory national cultural heritage
lower Vítkovice. City of Ostrava used to be industrial superpower of
the Czechoslovak Republic, especially in the area of coal mining and
iron production, after declining industrial production and mining in
the 80s left many unused areas of former factories generally
brownfields and backfields. Since the late 90s we are observing how
the city officials or private entities seeking to remedy this situation.
Regeneration of brownfields is a very expensive and long-term
process. The area is now rebuilt for tourists and residents of the city
in the entertainment, cultural, and social center. It was necessary do
the reconstruction of the industrial monuments. Equally important
was the construction of new buildings, which helped reusing of the
entire complex. This is a unique example of transformation of
technical monuments and completion of necessary new objects, so
that the area could start working again and reintegrate back into the
urban system.
Abstract: This paper presents results of compressive strength,
capillary water absorption, and density tests conducted on concrete
containing recycled aggregate (RCA) which is obtained from
structural waste generated by the construction industry in Turkey. In
the experiments, 0%, 15%, 30%, 45% and 60% of the normal
(natural) coarse aggregate was replaced by the recycled aggregate.
Maximum aggregate particle sizes were selected as 16 mm, 22,4 mm
and 31,5 mm; and 0,06%, 0,13% and 0,20% of air-entraining agent
(AEA) were used in mixtures. Fly ash and superplasticizer were used
as a mineral and chemical admixture, respectively. The same type
(CEM I 42.5) and constant dosage of cement were used in the study.
Water/cement ratio was kept constant as 0.53 for all mixture. It was
concluded that capillary water absorption, compressive strength, and
density of concrete decreased with increasing RCA ratio. Increasing
in maximum aggregate particle size and amount of AEA also affect
the properties of concrete significantly.
Abstract: In this study, the feasibility of incorporating ceramic
waste from bricks (perforated brick and double hollow brick) and
extruded polystyrene (XPS) waste, is analysed.
Results show that it is possible to incorporate up to 25% of
ceramic waste and 4% of XPS waste over the weight of gypsum in a
gypsum matrix. Furthermore, with the addition of ceramic waste an
8% of surface hardness increase and a 25% of capillary water
absorption reduction can be obtained. On the other hand, with the
addition of XPS, a 26% reduction of density and a 37% improvement
of thermal conductivity can be obtained.
The obtained results are favorable to use these materials in order to
produce prefabricated gypsum and also as material for interior
cladding walls.
Abstract: Construction projects are information intensive in
nature and involve many activities that are related to each other.
Wireless technologies can be used to improve the accuracy and
timeliness of data collected from construction sites and shares it with
appropriate parties. Nonetheless, the construction industry tends to be
conservative and shows hesitation to adopt new technologies. A main
concern for owners, contractors or any person in charge on a job site
is the cost of the technology in question. Wireless technologies are
not cheap. There are a lot of expenses to be taken into consideration,
and a study should be completed to make sure that the importance
and savings resulting from the usage of this technology is worth the
expenses. This research attempts to assess the effectiveness of using
the appropriate wireless technologies based on criteria such as
performance, reliability, and risk. The assessment is based on a utility
function model that breaks down the selection issue into alternatives
attribute. Then the attributes are assigned weights and single
attributes are measured. Finally, single attribute are combined to
develop one single aggregate utility index for each alternative.
Abstract: This paper presents Carrier Sense Multiple Access
(CSMA) communication models based on SoC design methodology.
Such a model can be used to support the modeling of the complex
wireless communication systems. Therefore, the use of such
communication model is an important technique in the construction
of high-performance communication. SystemC has been chosen
because it provides a homogeneous design flow for complex designs
(i.e. SoC and IP-based design). We use a swarm system to validate
CSMA designed model and to show how advantages of incorporating
communication early in the design process. The wireless
communication created through the modeling of CSMA protocol that
can be used to achieve communication between all the agents and to
coordinate access to the shared medium (channel).
Abstract: The paper is focused on monitoring of dependencies
of different composition concretes on elastic modulus values.
To obtain a summary of elastic modulus development in dependence
of concrete composition design variability was the objective
of the experiment. Essential part of this work was initiated
as a reaction to building practice when questions of elastic moduli
arose at the same time and which mostly did not obtain the required
and expected values from concrete constructions.
Abstract: Fibre cement plates, often used in construction,
generally are made using quartz as an inert material, cement as a
binder and cellulose as a fibre. This paper, first of all, investigates the
mechanical properties and durability of fibre cement plates when
quartz is both partly and fully replaced with diatomite. Diatomite
does not only have lower density compared to quartz but also has
high pozzolanic activity. The main objective of this paper is the
investigation of the effects of supplementary cementing materials
(SCMs) on the short and long term mechanical properties and
durability characteristics of fibre cement plates prepared using
diatomite. Supplementary cementing materials such as ground
granulated blast furnace slug (GGBS) and fly ash (FA) are used in
this study. Volume proportions of 10, 20, 30 and 40% of GGBS and
FA are used as partial replacement materials to cement. Short and
long term mechanical properties such as compressive and flexural
strengths as well as sorptivity characteristics and mass were
investigated. Consistency and setting time at each replacement levels
of SCMs were also recorded. The effects of using supplementary
cementing materials on the carbonation and sulphate resistance of
fibre cement plates were then experimented. The results, first of all,
show that the use of diatomite as a full or partial replacement to
quartz resulted in a systematic decrease in total mass of the fibre
cement plates. The reduction of mass was largely due to the lower
density and finer particle size of diatomite compared to quartz. The
use of diatomite did not only reduce the mass of these plates but also
increased the compressive strength significantly as a result of its high
pozzolanic activity. The replacement levels of both GGBS and FA
resulted in a systematic decrease in short term compressive strength
with increasing replacement levels. This was essentially expected as
the total rate of hydration is much lower in GGBS and FA than that
of cement. Long term results however, indicated that the compressive
strength of fibre cement plates prepared using both GGBS and FA
increases with time and hence the compressive strength of plates
prepared using SCMs is either equivalent or more than the
compressive strength of plates prepared using cement alone.
Durability characteristics of fibre cement plates prepared using SCMs
were enhanced significantly. Measurements of sopritivty
characteristics were also indicated that the plates prepared using
SCMs has much lower water absorption capacities compared to
plates prepared cement alone. Much higher resistance to carbonation
and sulphate attach were observed with plates prepared using SCMs.
The results presented in this paper show that the use of SCMs does
not only support the production of more sustainable construction
materials but also enhances the mechanical properties and durability
characteristics of fibre cement plates.
Abstract: This paper presents an experimental study on
structural performance of an innovative noise barrier consisting of
poly-block, light polyurethane foam (LPF) and polyurea. This wall
system (flexi-wall) is intended to be employed as a vertical extension
to existing sound barriers in an accelerated construction method. To
aid in the wall design, several mechanical tests were conducted on
LPF specimens and two full-scale walls were then fabricated
employing the same LPF material. The full-scale walls were
subjected to lateral loading in order to establish their lateral
resistance. A cyclic fatigue test was also performed on a full-scale
flexi-wall in order to evaluate the performance of the wall under a
repetitive loading condition. The result of the experiments indicated
the suitability of flexi-wall in accelerated construction and confirmed
that the structural performance of the wall system under lateral
loading is satisfactory for the sound barrier application. The
experimental results were discussed and a preliminary design
procedure for application of flexi-wall in sound barrier applications
was also developed.
Abstract: Construction and reconstruction of settlements and
individual municipalities, environmental management and the
creation, deployment of the forces of production and building
transport and technical equipment requires a large expenditure of
material and human resources. That is why the economic aspects of
the majority decision in these planes built in the foreground and are
often decisive. Thereby but more serious is that the economic aspects
of the settlement, the creation and function remain in their whole,
unprocessed, and cannot speak of a set of individual techniques and
methods traditional indicators and experiments with new approaches.
This is true both at the level of the national economy, and in their
own urban designs. Still a few remain identified specific economic
shaping patterns of settlement and the less it is possible to speak of
their control. Also practical assessing economics of specific solutions
are often used non-apt indicators in addition to economics usually
identifies with the lowest acquisition cost or high-intensity land use
with little regard for functional efficiency and little studied much
higher operating and maintenance costs".
Abstract: The future and the development of science is therefore
seen in interdisciplinary areas such as biomedical engineering. Selfassembled
structures, similar to stem cell niches would inhibit fast
division process and subsequently capture the stem cells from the
blood flow. By means of surface topography and the stiffness as well
as microstructure progenitor cells should be differentiated towards
the formation of endothelial cells monolayer which effectively will
inhibit activation of the coagulation cascade. The idea of the material
surface development met the interest of the clinical institutions,
which support the development of science in this area and are waiting
for scientific solutions that could contribute to the development of
heart assist systems. This would improve the efficiency of the
treatment of patients with myocardial failure, supported with artificial
heart assist systems. Innovative materials would enable the redesign,
in the post project activity, construction of ventricular heart assist.
Abstract: Riveting process is one of the important ways to keep
fastening the lap joints in aircraft structures. Failure of aircraft lap
joints directly depends on the stress field in the joint. An important
application of riveting process is in the construction of aircraft
fuselage structures. In this paper, a 3D finite element method is
carried out in order to optimize residual stress field in a riveted lap
joint and also to estimate its fatigue life. In continue, a number of
experiments are designed and analyzed using design of experiments
(DOE). Then, Taguchi method is used to select an optimized case
between different levels of each factor. Besides that, the factor which
affects the most on residual stress field is investigated. Such
optimized case provides the maximum residual stress field. Fatigue
life of the optimized joint is estimated by Paris-Erdogan law. Stress
intensity factors (SIFs) are calculated using both finite element
analysis and experimental formula. In addition, the effect of residual
stress field, geometry and secondary bending are considered in SIF
calculation. A good agreement is found between results of such
methods. Comparison between optimized fatigue life and fatigue life
of other joints has shown an improvement in the joint’s life.
Abstract: This paper reviews the model-based qualitative and
quantitative Operations Management research in the context of
Construction Supply Chain Management (CSCM). Construction
industry has been traditionally blamed for low productivity, cost and
time overruns, waste, high fragmentation and adversarial
relationships. The construction industry has been slower than other
industries to employ the Supply Chain Management (SCM) concept
and develop models that support the decision-making and planning.
However the last decade there is a distinct shift from a project-based
to a supply-based approach of construction management. CSCM
comes up as a new promising management tool of construction
operations and improves the performance of construction projects in
terms of cost, time and quality. Modeling the Construction Supply
Chain (CSC) offers the means to reap the benefits of SCM, make
informed decisions and gain competitive advantage. Different
modeling approaches and methodologies have been applied in the
multi-disciplinary and heterogeneous research field of CSCM. The
literature review reveals that a considerable percentage of the CSC
modeling research accommodates conceptual or process models
which present general management frameworks and do not relate to
acknowledged soft Operations Research methods. We particularly
focus on the model-based quantitative research and categorize the
CSCM models depending on their scope, objectives, modeling
approach, solution methods and software used. Although over the last
few years there has been clearly an increase of research papers on
quantitative CSC models, we identify that the relevant literature is
very fragmented with limited applications of simulation,
mathematical programming and simulation-based optimization. Most
applications are project-specific or study only parts of the supply
system. Thus, some complex interdependencies within construction
are neglected and the implementation of the integrated supply chain
management is hindered. We conclude this paper by giving future
research directions and emphasizing the need to develop optimization
models for integrated CSCM. We stress that CSC modeling needs a
multi-dimensional, system-wide and long-term perspective. Finally,
prior applications of SCM to other industries have to be taken into
account in order to model CSCs, but not without translating the
generic concepts to the context of construction industry.
Abstract: In this work, the Ictalurus punctatus species estimated
available physical habitat is compared with the estimated physical
habitat for the same but modified river reach, with the aim of creating
a linear park, along a length of 5 500 m.
To determine the effect of ecological park construction, on
physical habitat of the Lerma river stretch of study, first, the available
habitat for the Ictalurus punctatus species was estimated through the
simulation of the physical habitat, by using surveying, hydraulics,
and habitat information gotten at the river reach in its actual situation.
Second, it was estimated the available habitat for the above species,
upon the simulation of the physical habitat through the proposed
modification for the ecological park creation. Third, it is presented a
comparison between both scenarios in terms of available habitat
estimated for Ictalurus punctatus species, concluding that in cases of
adult and spawning life stages, changes in the channel to create an
ecological park would produce a considerable loss of potentially
usable habitat (PUH), while in the case of the juvenile life stage PUH
remains virtually unchanged, and in the case of life stage fry the PUH
would increase due to the presence of velocities and depths of lesser
magnitude, due to the presence of minor flow rates and lower volume
of the wet channel.
It is expected that habitat modification for linear park construction
may produce the lack of Ictalurus punktatus species conservation at
the river reach of the study.
Abstract: A sensory network consists of multiple detection
locations called sensor nodes, each of which is tiny, featherweight
and portable. A single path routing protocols in wireless sensor
network can lead to holes in the network, since only the nodes
present in the single path is used for the data transmission. Apart
from the advantages like reduced computation, complexity and
resource utilization, there are some drawbacks like throughput,
increased traffic load and delay in data delivery. Therefore, multipath
routing protocols are preferred for WSN. Distributing the traffic
among multiple paths increases the network lifetime. We propose a
scheme, for the data to be transmitted through a dominant path to
save energy. In order to obtain a high delivery ratio, a basic route
reconstruction protocol is utilized to reconstruct the path whenever a
failure is detected. A basic reconstruction routing (BRR) algorithm is
proposed, in which a node can leap over path failure by using the
already existing routing information from its neighbourhood while
the composed data is transmitted from the source to the sink. In order
to save the energy and attain high data delivery ratio, data is
transmitted along a multiple path, which is achieved by BRR
algorithm whenever a failure is detected. Further, the analysis of
how the proposed protocol overcomes the drawback of the existing
protocols is presented. The performance of our protocol is compared
to AOMDV and energy efficient node-disjoint multipath routing
protocol (EENDMRP). The system is implemented using NS-2.34.
The simulation results show that the proposed protocol has high
delivery ratio with low energy consumption.
Abstract: To solve these problems, we investigated the management system of heating enterprise, including strategic planning based on the balanced scorecard (BSC), quality management in accordance with the standards of the Quality Management System (QMS) ISO 9001 and analysis of the system based on expert judgment using fuzzy inference. To carry out our work we used the theory of fuzzy sets, the QMS in accordance with ISO 9001, BSC, method of construction of business processes according to the notation IDEF0, theory of modeling using Matlab software simulation tools and graphical programming LabVIEW. The results of the work are as follows: We determined possibilities of improving the management of heat-supply plant-based on QMS; after the justification and adaptation of software tool it has been used to automate a series of functions for the management and reduction of resources and for the maintenance of the system up to date; an application for the analysis of the QMS based on fuzzy inference has been created with novel organization of communication software with the application enabling the analysis of relevant data of enterprise management system.
Abstract: In this study, the pedestrian simulation VISWALK
integration and application platform ant algorithms written program
made to construct a renovation engineering schedule planning mode.
The use of simulation analysis platform construction site when the user
running the simulation, after calculating the user walks in the case of
construction delays, the ant algorithm to find out the minimum delay
time schedule plan, and add volume and unit area deactivated loss of
business computing, and finally to the owners and users of two
different positions cut considerations pick out the best schedule
planning. To assess and validate its effectiveness, this study
constructed the model imported floor of a shopping mall floor
renovation engineering cases. Verify that the case can be found from
the mode of the proposed project schedule planning program can
effectively reduce the delay time and the user's walking mall loss of
business, the impact of the operation on the renovation engineering
facilities in the building to a minimum.
Abstract: Metal thin-walled members have been widely used in
building industry. Usually they are utilized as purlins, girts or ceiling
beams. Due to slenderness of thin-walled cross-sections these
structural members are prone to stability problems (e.g. flexural
buckling, lateral torsional buckling). If buckling is not
constructionally prevented their resistance is limited by buckling
strength. In practice planar members of roof or wall cladding can be
attached to thin-walled members. These elements reduce
displacement of thin-walled members and therefore increase their
buckling strength. If this effect is taken into static assessment more
economical sections of thin-walled members might be utilized and
certain savings of material might be achieved. This paper focuses on
problem of determination of critical load of steel thin-walled beams
with lateral continuous restraint which is crucial for lateral torsional
buckling assessment.
Abstract: In order to address construction project requirements
and specifications, scholars and practitioners need to establish
taxonomy according to a scheme that best fits their need. While
existing characterization methods are continuously being improved,
new ones are devised to cover project properties which have not been
previously addressed. One such method, the Project Definition Rating
Index (PDRI), has received limited consideration strictly as a
classification scheme. Developed by the Construction Industry
Institute (CII) in 1996, the PDRI has been refined over the last two
decades as a method for evaluating a project's scope definition
completeness during front-end planning (FEP). The main
contribution of this study is a review of practical project classification
methods, and a discussion of how PDRI can be used to classify
projects based on their readiness in the FEP phase. The proposed
model has been applied to 59 construction projects in Ontario, and
the results are discussed.