The Civil Engineering Industry has a significant role in developing the nation to cater to the need for globalizing market scenarios. In every aspect of infrastructural development, the role and involvement of Civil Engineering experts are inevitable. The knowledge about the process and standards should be known to all. It will be much helpful for anyone, involving in Civil Engineering work at any time reference for their professional knowledge.
Green concrete is a revolutionary topic in the history of concrete
industry. This was first invented in Denmark in the year 1998. Green
concrete has nothing to do with colour. It is a concept of thinking
environment into concrete considering every aspect from raw materials
manufacture over mixture design to structural design, construction, and
service life.
Green concrete is very often also cheap to produce, because, for
example, waste products are used as a partial substitute for cement,
charges for the disposal of waste are avoided, energy consumption in
production is lower, and durability is greater. Green concrete is a type
of concrete which resembles the conventional concrete but the
production or usage of such concrete requires minimum amount of energy
and causes least harm to the environment. The CO2 emission related to
concrete production, inclusive of cement production, is between 0.1 and
0.2 t per tonne of produced concrete.
However, since the total amount of concrete produced is so vast the
absolute figures for the environmental impact are quite significant,
due to the large amounts of cement and concrete produced. Since concrete
is the second most consumed entity after water it accounts for around
5% of the world‘s total CO2 emission (Ernst Worrell, 2001). The solution
to this environmental problem is not to substitute concrete for other
materials but to reduce the environmental impact of concrete and cement.
Pravin Kumar et al, 2003, used quarry rock dust along with fly ash and
micro silica and reported satisfactory properties.
The potential environmental benefit to society of being able to
build with green concrete is huge. It is realistic to assume that
technology can be developed, which can halve the CO2 emission related to
concrete production. With the large consumption of concrete this will
potentially reduce the world‘s total CO2 emission by 1.5-2%. Concrete
can also be the solution to environmental problems other than those
related to CO2 emission. It may be possible to use residual products
from other industries in the concrete production while still maintaining
a high concrete quality. During the last few decades society has become
aware of the deposit problems connected with residual products, and
demands, restrictions and taxes have been imposed.
It's possible that you as a contractor will never have to face up to
the problems that air entrainment can cause when it's either too high
or too low in concrete. For you, reading this article will serve as
background information. Hopefully this information also will cause you
to think more proactively to resolve problems involving air entrainment
before concrete is placed.
Air entraining admixtures can be troublemakers, but necessary ones.
By a wide margin, they create more problems for ready-mix producers,
contractors, and owners than all the other admixtures. Almost everything
influences them: ambient and concrete temperatures, the time it takes a
ready-mix truck to travel from the batch plant to the jobsite, mixing
time, the configuration of the mixing drum and the condition of the
mixing blades, the water-cement ratio of a mix, the type of portland
cement used, and other admixtures (especially polycarboxylate
superplasticizers), to name a few.
Owners might accept scaling in
plain concrete but not for colored decorative concrete. This failure
probably is due to low air entrainment.
When entrained air is too high, contractors can experience problems
when they finish it, especially when troweling machines are used. Too
much air also can cause problems when contractors stamp decorative
patterns in concrete. Concrete installed outdoors in freeze/thaw
climates without adequate air entrainment is especially susceptible to
scaling during the first or second winter. Placing concrete with too
much or too little air entrainment becomes the contractor's problem.
Even if tests eventually determine that others are responsible, the
concrete contractor is invariably the one to face an upset owner,
experience cash flow issues, and possibly have to remove and replace
work at their own expense. With this in mind, measuring and adjusting
air entrainment when concrete (especially first loads) arrives on the
jobsite becomes a way to manage risk.
Air and what it does
In simplest terms, air entraining admixtures are surfactants, such
as soap. They interact with the alkalinity of concrete to produce huge
volumes of small spherical air bubbles that typically range from 0.006
to 0.008 inch in diameter. Ideally they are spaced no more than about
0.008 inches apart or less. When air entrainment is added to concrete,
there is some effect on slump, and compressive strength is reduced by
about 500 psi in a standard 6-bag (564-pound) mix.
There are two kinds of air in concrete: entrapped and entrained.
Entrapped air is a result of the mixing process. As concrete is being
mixed about 1.5% air becomes entrapped. The bubbles are shaped
irregularly and have no effect on the concrete's durability because they
are too large, easily seen by the eye. Entrained bubbles are the
opposite. They are spherical, are best viewed under a microscope, and
provide durability under freeze/thaw conditions.
When you measure air in concrete, the percentage reading represents
the total amount of air—entrapped and entrained air. For example, if the
reading on an air meter is 6% air, it means that approximately 1.5% of
the total is entrapped air and 4.5% is entrained air. Though readings
are reported always as percentages, the percentage number isn't what
really counts. It's the size of the entrained bubbles and the space
between them that is important. This usually is determined by
petrographic analysis of hardened concrete. So percentage numbers
provide approximate results. Different mixes, depending on aggregate
sizes and the amount of cement powder in a mix, have different
percentage requirements. For example, one mix might need 6% air while
another needs only 4%. In each case, the bubble size and spacing should
be the same. When a pressure test isn't performed correctly, the error
usually results in higher readings.
Air entraining admixtures are used for three primary reasons. They
always are specified for concrete exposed to freeze/thaw conditions.
Occasionally, they are used to prevent bleeding—water coming to the
surface of freshly placed concrete (remember, water is required to make
bubbles). They also are used to reduce unit weights of concrete,
especially for lightweight aggregate mixes, reducing unit weight beyond
what the aggregates can provide.
Types of air entrainment
There are two general classifications today—wood-derived acid salts
(Vinsol resins) and synthetic resins. Vinsol resins have been on the
market the longest and many ready-mix producers continue to use them
because they are familiar with them. They work especially well with very
low water-cement mixes, developing good bubble structures—and are ideal
for road pavements. But when slump exceeds 6 inches, including placing
slumps when superplasticizers are added, entrainment readings begin to
decrease. Percentages also decrease the longer concrete mixes are in the
truck. After an hour in the truck, concrete can lose as much as 1% air
(0.25% every 15 minutes) and more admixture should be added.
Synthetic resins have exotic generic names such as “fatty acids,”
“gum resins,” and “tall oils” and have been in the marketplace for only a
few years. These admixtures can produce smaller bubble sizes spaced
closer together than Vinsol resins, offering greater durability under
freeze/thaw conditions. But they also entrain more air as slumps
increase, and can cause readings to be excessive. For example if a wet
load arrives on a jobsite with specified 6% air entrainment, or if your
crew adds water to make 6-inch or higher slumps, air entrainment
readings can increase to 20% and even higher, compromising other
properties of the concrete. You should measure the air before placing
concrete under these conditions.
Air entrained concrete has effects on compressive strength of concrete and its workability. Air entrained concrete increases the workability of concrete without much increase in water-cement ratio.Compressive strength of concrete is inversely proportional to
workability of concrete. When workability of concrete increases, its
compressive strength decreases. To achieve the required compressive
strength of concrete, its workability is limited. But workability cannot
be decreased beyond certain limit so that concrete can be effectively
placed and compacted at site.
Effect of Air Entrained Concrete on Strength of Concrete:
To
maintain the desired compressive strength and workability of concrete
together, generally in the case of higher strength concrete, admixtures
are used. Air entraining agent is one such concrete admixture to
increase the workability without affecting much reduction in compressive
strength.
But use of concrete
admixture in concrete shall be considered in mix design so that desired
compressive strength is achieved with required amount of admixture and
workability.
Fig: Air Entrained Concrete
In
general, the compressive strength of concrete is reduced by use of air
entrained admixture. The amount of reduction in strength depends on many
factors such as mix proportions, type and grading of concrete, cement
and actual air-entraining agent.
Normal
reduction in strength of concrete by use of air-entrained admixtures
varies from 3 to 7%. This variation of strength shall be considered in
the mix design of concrete. Suitably, trial mix designs should be done
to find exact variation of strength with the use of this admixture and
suitable corrections should be done in mix design to ensure desired
strength.
Typically
it may be assumed that a loss of 5% in compressive strength of concrete
occurs due to each 1% by volume of entrained air in the concrete mix.
In
order to estimate water-cement ratio required for an air entrained
concrete, an allowance for strength reduction is incorporated in the mix
design and higher target mean strength is assumed.
The appropriate higher target mean strength for an air entrained mix is given by:
ir-entrained concrete contains billions
of microscopic air cells per cubic foot. These air pockets relieve
internal pressure on the concrete by providing tiny chambers for water
to expand into when it freezes. Air-entrained concrete is produced using
air-entraining portland cement, or by the introduction of
air-entraining agents, under careful engineering supervision, as the
concrete is mixed on the job. The amount of entrained air is usually
between four and seven percent of the volume of the concrete, but may be
varied as required by special conditions.
View Finishing Air Entrained Concrete for additional information.
2.
DEFINITION concrete which uses lightweight aggregates May
consist of lightweight aggregates are used in ordinary concrete of
coarse aggregate and sand, clay, foamed slag, clinker, crushed
stone, aggregates of organic and inorganic.
3.
Methods of preparation of lightweight concrete
2.Without providing
concrete smoother 1.Preparation of porous (rough
concrete) concrete 3.Providing
lightweight aggregate concrete
4.
1.PREPARATION OF POROUS CONCRETEa) Lightweight concrete
obtained byinserting gas bubbles or air into the mixtureof plastic
cement (mixed with fine sand)b) Lightweight concrete did not
containstones included as porous mortar.
5.
Characteristics of porous concrete : 1. high thermal
insulation 2. a high moisture
movement 3. a high
shrinkage POROUS CONCRETE
6.
Types of porous concrete a) type of cast in situ b) type of first cast
7.
Aggregates used shall comply with the following conditions: a) At
least c) Stone did 95% of
not diffuse aggregates through the must be via b)
The stone BS 4mm the 18mm aggregate used sieve. BS
sieve. shall not exceed 10% by 10 mm
BS sieve.
8.
2. Preparation of concrete without the smooth (rough concrete)
Lightweight concrete such as is obtained when
the fine aggregate (sand) is not used and the
concrete mix of cement, water and coarse aggregates.
Concrete can be used for structural purposes and
not to bear burden to bear a load.
9.
3. Preparation of lightweight aggregate concrete•
Concrete is often used in:
b) the roof and walls
cast in situ for use in
insulation. a)
before pouring the concrete block feature of lightweight
aggregate concrete.
10.
The main purpose of the concrete requirements are:
c) have low b) have a
lowa) has sufficient drying shrinkage
density (for strength (to
avoid better insulation)
cracking/rift)
11.
The above factors depend on: a) types of aggregates used
b) the mixture c) the d) the
density methods and techniques of
preservation
12.
Characteristics ofLightweight Concrete Thermal Fire
insulation insulation Durability Rain Acoustic Water
penetration properties absorption
13.
Thermal insulationThermal insulation efficiency is defined as
resistanceto heat flow either through conduction, or
radiation.Lightweight concrete has a high heat insulationresistance.such
as porous concrete walls 150mm to provide fourtimes better insulation
than 225mm thick brick wall.
14.
Fire insulation• Fire prevention is associated with thermal
insulation. two types of
fire protection
b) a non-combustible a) combustible materials -
such as materials - such non-organic materials as
organic such as wood
stone, bricks, rocks and
other.
15.
DurabilityIt is defined as the ability to bear the effects of
environmentsuch as the effects of chemical, physical stress and
mechanicaleffects. The intended effect of the chemical, including
groundwater containing sulfate, air pollution and reactive liquid
spills.Physical stress is the shrinkage, the stresses oftemperature,
cooled, and others. If all the physical stress willcause cracks in the
structure of lightweight concrete.Mechanical effect is the impact and
costs are excessive. Thesituation in the steel structure unit should be
protected fromrusting.
16.
Water absorptionAbsorption water by the concrete is high andmore
than that found in solid concrete. This isbecause the lightweight
concrete has holes in it.
17.
Penetration of rain water It is an important element to the wall
18.
Acoustic propertiesThe key factor is the density ofthe sound
insulation material.Therefore, for soundinsulation, lightweight
concretecan not show the desiredcharacteristics.
19.
ii) Economical ini) rapid and
terms ofrelatively transportation
assimple well as
reductionconstruction in manpower
Advantages
iv) Most of lightweight
concrete haveiii) Significant reduction better nailing
and sawingof overall propertiesweight
results in saving than heavier and strongerstructural
convensional concreteframes, footing or
piles
20.
Disadvantages i) Very sensitive with
water content
in the mixtures
iii) Mixing time is
longer than ii) Difficult to place and finish
conventional because of the porosity and
concrete to assure angularity of the aggregate. In
proper mixing some mixes the cement mortar may separate the
aggregate and float towards the surface
The ultra-high-performance concrete is
promising for use in construction sector due to its high tensile and
flexural performance coupled with its high compressive strength. Despite
these advantages, its high commercial cost which is mainly due to high
price of steel fiber and superplasticizer along with additional cost for
heat curing remains a big challenge.
In order to curb this challenge,
researchers have tried to reduce the required amounts by using different
types of steel fibers. It is also important to analyze factors that
influence the tensile and flexural performances of
ultra-high-performance concrete as they have been considered by previous
studies to be major influencers.
Research by Professor Young-Soo Yoon
from Korea University, Dr. Doo-Yeol Yoo from Hanyang University and Dr.
Su-Tae Kang at Daegu University investigated the flexure performance of
an ultra-high-performance concrete UHPC beams according to
their fiber length with the consideration of fiber distribution
characteristics such as fiber orientation, fiber dispersion, and number
of fibers in a unit area. The study is published in journal, Composite Structures.
From test results, it was seen that all
series exhibited deflection-hardening behavior generating a higher load
carrying capacity after first cracking. Beams with longer fiber length
had higher load carrying capacity and deflection capacity as minute
effect on post-peak ductility was seen.
After investigations on load carrying capacity and toughness at points of limit of proportionality and modulus of rupture MOR
and other deflection points L/600(d0.5), L/150(d2), L/100(d3) and
L/75(d4), results show that the fiber length of 19.5mm exhibited the
highest load and toughness and magnitude of load. Toughness decreases
with a decrease in fiber length except at point of proportionality. The
insignificant difference observed in the limit of proportionality was
due to the fact that first cracking behavior is more influenced by the
matrix strength rather than fiber bridging which is consistent with
findings from Yoo et al. Int. J. Dam Mech 2015.
Binary image analysis results on fiber
orientation and dispersion showed that for all test series, fibers near
the wall of the mold tends to be more aligned in the flow direction than
those being further from the wall as a result of wall effect. Poorer
fiber dispersion was obtained near the end of the specimens at the point
of placing concrete than the center of specimen which is due to
alignment of fibers parallel to cutting plane as a result of zero
velocity of flow at the end wall.
Lowest coefficients of fiber
orientation, dispersion and lowest number of fibers in a unit area were
obtained near the end of the specimen for all test series. Coefficients
of fiber dispersion increased with increasing flow distance up to 80mm
and similar values thereafter. However, higher packing density and fiber
orientation coefficient was obtained along the flow distance when
shorter fiber length was used. This result means that shorter fiber
length tends to be aligned parallel to flow direction than a longer
fiber length.
Finite element analysis showed flexural
strengths lesser than the experimentally obtained values for beams with
fiber length of 13mm. However, using a discrete crack approach with the
suggested tri-linear tension-softening curve, fairly well predicted the
experimental load-deflection responses of the ultra-high-performance
concrete beams with various fiber length.
This study finding on
flexural performance of ultra-high-performance concrete beams according
to their fiber length provides another avenue of reducing high cost
associated with ultra-high-performance concrete.
About The Author
Doo-Yeol Yoo, Department of Architectural Engineering, Hanyang University, Seoul, Korea.
Doo-Yeol Yoo is an Assistant Professor
in the Department of Architectural Engineering at Hanyang University,
Seoul, South Korea. He received his BS and PhD from Korea University,
Seoul, South Korea and was a Postdoctoral Fellow at The University of
British Columbia, Vancouver, BC, Canada. His research interests include
the design, analysis, and modeling of fiber-reinforced cementitous
composites.
About The Author
Young-Soo Yoon,School of Civil, Environmental and Architectural Engineering, Korea University, South Korea
Young-Soo Yoon is a Professor in the
School of Civil, Environmental and Architectural Engineering at Korea
University, Seoul, South Korea. He received his PhD from McGill
University, Montreal, QC, Canada. His research interests include shear
behavior, high-performance concrete, ultra-high-strength concrete, and
structural use of fibers.
About The Author
Su-Tae Kang, Department of Civil Engineering, Daegu University, Gyeongsan, Korea.
Su-Tae Kang is an Assistant Professor in
the Department of Civil Engineering at Daegu University, Gyeongsan,
South Korea. He received his PhD from Korea Advanced Institute of
Science and Technology, Daejeon, South Korea. His research interests
include fiber reinforced cementitious composites, characterization of
mechanical and non-mechanical properties of cement based materials, and
structural application of fiber reinforced concrete.
Journal Reference
Doo-Yeol Yoo1, Su-Tae Kang2, Young-Soo Yoon3. Enhancing the flexural performance of ultra-high performance concrete using long steel fibers, Composite Structures, Volume 147, 2016, Pages 220–230. Show AffiliationsAbstract
In this study, the flexural performance
and fiber distribution characteristics of ultra-high-performance
concrete (UHPC) were investigated according to the fiber length. To do
this, three different fiber lengths having an identical diameter were
used. Enhancements in flexural strength and energy absorption capacity
were observed when longer fibers (or higher aspect ratios of fiber) were
used, whereas insignificant effect of fiber length on the first
cracking properties (i.e., first cracking strength and corresponding
deflection) was obtained. Fiber length had a little influence on the
degree of fiber dispersion, but a significant influence on the fiber
orientation. A higher fiber orientation coefficient along the flow
distance was obtained when shorter fibers were used. A finite element
analysis incorporating previously suggested material models was
performed and verified by comparing the analytical results with the
present experimental data.
The ultra-high-performance concrete is
promising for use in construction sector due to its high tensile and
flexural performance coupled with its high compressive strength. Despite
these advantages, its high commercial cost which is mainly due to high
price of steel fiber and superplasticizer along with additional cost for
heat curing remains a big challenge.
In order to curb this challenge,
researchers have tried to reduce the required amounts by using different
types of steel fibers. It is also important to analyze factors that
influence the tensile and flexural performances of
ultra-high-performance concrete as they have been considered by previous
studies to be major influencers.
Research by Professor Young-Soo Yoon
from Korea University, Dr. Doo-Yeol Yoo from Hanyang University and Dr.
Su-Tae Kang at Daegu University investigated the flexure performance of
an ultra-high-performance concrete UHPC beams according to
their fiber length with the consideration of fiber distribution
characteristics such as fiber orientation, fiber dispersion, and number
of fibers in a unit area. The study is published in journal, Composite Structures.
From test results, it was seen that all
series exhibited deflection-hardening behavior generating a higher load
carrying capacity after first cracking. Beams with longer fiber length
had higher load carrying capacity and deflection capacity as minute
effect on post-peak ductility was seen.
After investigations on load carrying capacity and toughness at points of limit of proportionality and modulus of rupture MOR
and other deflection points L/600(d0.5), L/150(d2), L/100(d3) and
L/75(d4), results show that the fiber length of 19.5mm exhibited the
highest load and toughness and magnitude of load. Toughness decreases
with a decrease in fiber length except at point of proportionality. The
insignificant difference observed in the limit of proportionality was
due to the fact that first cracking behavior is more influenced by the
matrix strength rather than fiber bridging which is consistent with
findings from Yoo et al. Int. J. Dam Mech 2015.
Binary image analysis results on fiber
orientation and dispersion showed that for all test series, fibers near
the wall of the mold tends to be more aligned in the flow direction than
those being further from the wall as a result of wall effect. Poorer
fiber dispersion was obtained near the end of the specimens at the point
of placing concrete than the center of specimen which is due to
alignment of fibers parallel to cutting plane as a result of zero
velocity of flow at the end wall.
Lowest coefficients of fiber
orientation, dispersion and lowest number of fibers in a unit area were
obtained near the end of the specimen for all test series. Coefficients
of fiber dispersion increased with increasing flow distance up to 80mm
and similar values thereafter. However, higher packing density and fiber
orientation coefficient was obtained along the flow distance when
shorter fiber length was used. This result means that shorter fiber
length tends to be aligned parallel to flow direction than a longer
fiber length.
Finite element analysis showed flexural
strengths lesser than the experimentally obtained values for beams with
fiber length of 13mm. However, using a discrete crack approach with the
suggested tri-linear tension-softening curve, fairly well predicted the
experimental load-deflection responses of the ultra-high-performance
concrete beams with various fiber length.
This study finding on
flexural performance of ultra-high-performance concrete beams according
to their fiber length provides another avenue of reducing high cost
associated with ultra-high-performance concrete.
About The Author
Doo-Yeol Yoo, Department of Architectural Engineering, Hanyang University, Seoul, Korea.
Doo-Yeol Yoo is an Assistant Professor
in the Department of Architectural Engineering at Hanyang University,
Seoul, South Korea. He received his BS and PhD from Korea University,
Seoul, South Korea and was a Postdoctoral Fellow at The University of
British Columbia, Vancouver, BC, Canada. His research interests include
the design, analysis, and modeling of fiber-reinforced cementitous
composites.
About The Author
Young-Soo Yoon,School of Civil, Environmental and Architectural Engineering, Korea University, South Korea
Young-Soo Yoon is a Professor in the
School of Civil, Environmental and Architectural Engineering at Korea
University, Seoul, South Korea. He received his PhD from McGill
University, Montreal, QC, Canada. His research interests include shear
behavior, high-performance concrete, ultra-high-strength concrete, and
structural use of fibers.
About The Author
Su-Tae Kang, Department of Civil Engineering, Daegu University, Gyeongsan, Korea.
Su-Tae Kang is an Assistant Professor in
the Department of Civil Engineering at Daegu University, Gyeongsan,
South Korea. He received his PhD from Korea Advanced Institute of
Science and Technology, Daejeon, South Korea. His research interests
include fiber reinforced cementitious composites, characterization of
mechanical and non-mechanical properties of cement based materials, and
structural application of fiber reinforced concrete.
Journal Reference
Doo-Yeol Yoo1, Su-Tae Kang2, Young-Soo Yoon3. Enhancing the flexural performance of ultra-high performance concrete using long steel fibers, Composite Structures, Volume 147, 2016, Pages 220–230. Show AffiliationsAbstract
In this study, the flexural performance
and fiber distribution characteristics of ultra-high-performance
concrete (UHPC) were investigated according to the fiber length. To do
this, three different fiber lengths having an identical diameter were
used. Enhancements in flexural strength and energy absorption capacity
were observed when longer fibers (or higher aspect ratios of fiber) were
used, whereas insignificant effect of fiber length on the first
cracking properties (i.e., first cracking strength and corresponding
deflection) was obtained. Fiber length had a little influence on the
degree of fiber dispersion, but a significant influence on the fiber
orientation. A higher fiber orientation coefficient along the flow
distance was obtained when shorter fibers were used. A finite element
analysis incorporating previously suggested material models was
performed and verified by comparing the analytical results with the
present experimental data.
Hargreaves et al. (2016) developed a
method of taking into account the variability of indoor and outdoor
space of housing when forecasting the suitability of decentralized
energy technologies. The research, published in the journal Applied Energy, substantially
improves the spatial estimates of thermal energy consumption when
compared to building energy models that use standard dwelling
typologies. It also forecast how spatial planning scenarios would
affect the suitability of decentralised energy supply.
The United Kingdom Future of Heating
report by the government Department of Energy and Climate Change (DECC)
proposed that decentralized energy supply, such as heat pumps and heat
networks, will provide a large proportion of future domestic heating and
make a substantial contribution to achieving future CO2
reduction targets. However, the DECC consultation on a domestic
renewable energy incentive scheme identified costs and uncertainty about
whether properties have the space for installation as important
barriers. This leads to the need for the future built form
characteristics and energy demands to be considered because they will
affect the suitability of decentralized technologies and their uptake
and cost effectiveness.
Research to carry out this investigation
was part of a case study of London and its surrounding regions in the
south east of England. It used urban modeling forecasts of the locations
and average densities of dwellings for year 2031, and an innovative
method of converting these densities into a representation of the
housing stock and plot sizes. It thereby combined the regional
simulation of urban form and building occupancies with the
building-scale modelling of energy demand and supply to test combined
scenarios for spatial planning policy, building regulations and
technologies.
Dwelling energy demands were estimated
using a Domestic Energy and Carbon Model (DECM) for predicting the
energy consumption and carbon dioxide emission of the English housing
stock. The decentralized energy supply options consisted of
community-scale and building integrated technologies. Cost effectiveness
was calculated as a relative measure against the most appropriate
reference case and was used to explore the cost of achieving a one tonne
reduction in CO2 emissions compared with paying a carbon
price of around £ 70/tonne. The future costs and efficiencies of
buildings and technologies were based on information available in 2009.
From the results, Hargreaves et al.
(2016) showed that lower density areas would have the greatest potential
for energy efficiency improvement by retrofitting because they would
have a greater proportion of less energy efficient dwelling types such
as detached and semi-detached houses. These would also have more garden
and roof space for low carbon technologies that could partly offset
their greater CO2 emissions. The integrated modeling
framework showed how differences in the densities of dwellings due to
spatial planning policies would affect their CO2 emissions and also the
reduction in these emissions achievable by the energy supply systems.
The energy supply systems were selected
based on the availability of suitable space, an initial estimate of
their likely uptake, and sized with respect to their connected energy
demand and operational characteristics. The results obtained show that
the decentralized energy supply technologies would make only a marginal
reduction in CO2 per capita for the case study regions in the forecast year of 2031 compared to conventional supply.
The UK has a policy to progressively de-carbonize the conventional energy supply and this will diminish the future CO2
reduction benefits of these local low-carbon technologies. None of the
decentralized supply technologies tested, except micro-chp & gas,
would be financially beneficial to households unless subsidized. Also,
the new-build dwellings would be much more energy efficient and so would
have less potential for further reduction in CO2 emissions by low carbon supply.
Hargreaves et al. 2016’s findings have
helped to improve the evidence base for strategies on achieving carbon
budgets and the results show that current strategies do not adequately
take into account how future residential space constraints would affect
the suitability of some of these decentralized technologies. Their
future uptake is therefore likely to be lower than expected and is
likely to decline unless there is continuing policy support. Also, they
will become less cost effective at reducing CO2 when compared to conventional supply unless there is continuing improvement in their performance and costs characteristics.
About The Author
Tony Hargreavesis
a chartered civil engineer and has been a Senior Research Fellow at
Birmingham University since 2015, and was previously a Senior Research
Associate for 12 years at Cambridge University, UK.
His research explores the
interdependencies between spatial planning and the suitability of
decentralised infrastructure for energy, travel, water and waste. This
has integrated the regional modelling of land use and transport with the
neighbourhood scale modelling of urban form to forecast how planning
policies and technology scenarios could be combined to improve the
sustainability and resilience of cities.
About The Author
Dr. Vicky Cheng
is the leader of the Energy Efficient and Smart Cities research group
at the Munich School of Engineering, Technische Universität München,
Germany. Prior to joining TU München, Vicky worked as a post-doctoral
researcher in the Department of Architecture, University of Cambridge
where she obtained her PhD. As well as academic research, Vicky has
served as an Associate in Cambridge Architectural Research Ltd. with
whom she has worked on consultancy projects for the UK and Scottish
governments in the topic of housing energy.
Vicky’s research is centred on urban
energy system modelling and analysis, particularly in the area of energy
system optimisation, heat and electricity sector coupling and
integration of renewable energy technologies.
About The Author
Sandip Deshmukhis
Associate Professor of Mechanical Engineering, BITS Pilani–Hyderabad
Campus, India. Sandip is associated with BITS Pilani in various
capacities from last thirteen years. He has also worked for four years
as a Research Fellow on EPSRC funded projects at the Centre for
Environmental Strategy, University of Surrey, Guildford, UK.
His main research interest relate to
regional energy planning with a focus on decentralized energy supply
options and energy resource allocation for socio-economic and
techno-economic development.
About The Author
Matthew Leach
is Professor of Energy and Environmental Systems at University of
Surrey, UK. Matthew is part of the multidisciplinary Centre for
Environment and Sustainability, where he recently completed six years as
Centre Director. He is a chartered mechanical engineer, with an MSc and
PhD in Energy Policy from Imperial College London. He has previously
been Vice President of the Energy Institute and Chair of Council of the
British Institute of Energy Economics.
Matthew has thirty years’ experience of
the challenges in delivering secure and sustainable energy services. His
research has focussed on decentralised energy supply systems and the
role of demand-side management, exploring the environmental and economic
performance of emerging technologies, and the roles for policy, in long
term transitions to a low carbon economy.
About The Author
Koen Steemers
is Professor of Sustainable Design at the Department of Architecture,
University of Cambridge. There he has been Head of Department (2008-14)
and Head of Research as Director of the Martin Centre (2003-08).
An architect and environmental design
specialist, Koen was listed as one of the “top 50 most influential
people in UK sustainability” by Building Design. His current work deals
with the architectural and urban implications of environmental issues
ranging from energy use to human well-being. Koen is a member of energy,
environment and health networks and has been developing
cross-disciplinary research initiatives.
Koen’s research activities are focused
on the environmental performance of buildings and cities – with a
particular interest in human perception and behaviour – which are the
topics of funded research projects and his 35 past and present PhD
students.
Koen has over 200 outputs (with over
4600 citations), with 10 books including “Energy and Environment in
Architecture” (2000), “Daylight Design of Buildings”
(2002), “Environmental Diversity in Architecture” (2004) and
“Sustainable Urban and Architectural Design” (2006).
Journal Reference
Anthony Hargreaves1, Vicky Cheng2, Sandip Deshmukh3, Matthew Leach4, Koen Steemers5.
Forecasting How Residential Urban Form Affects the Regional Carbon
Savings and Costs of Retrofitting and Decentralized Energy Supply. Applied Energy, Volume 186, Part 3, 15 January 2017, Pages 549–561.
Overloading of concrete structures leads
to short lifetime of structure or even collapse during extreme cases.
Rehabilitation of damaged concrete structures in order to meet
requirements after carrying high permissible load is a better
alternative to demolishing and rebuilding due to present economic
climate condition.
Ultra-high performance fiber-reinforced cementitious composite UHPFRCC
have been successfully applied in retrofitting or strengthening of
reinforced concrete beams. CARDIFRC, one of the techniques of UHPFRCC
has benefitting features such as tensile strength, stiffness and
coefficient of linear thermal expansion which are comparable with that
of parent member material.
However, CARDIFRC requires high cement
content which does not enhance concrete properties but increases
emission of greenhouse gases contributing to global warming. In order to
overcome this problem, a green-USM-reinforced concrete which has lesser
cement content (< 360Kg/m3) compared to 744Kg/m3 of CARDIFRC is currently being developed in Universiti Sains Malaysia USM.
Research conducted by Dr. Aldahdooh and colleagues expanded their findings on green-USM-reinforced concrete GUSMRC as a new green retrofitting material. The work published in Composite Structures
examined its flexural behaviors such as crack development, crack modes,
flexural capacity and deflection capacity of a reinforced concrete
before and after retrofitting
Results from crack development in
reinforced concrete beams before retrofitting showed that recorded
failure load of three beams of G(0) members was between the range of
37KN to 39.68KN and their failure mode was due to diagonal tension. The
third beam reached the highest load of 39.68KN (cycle 16).
The beam A-T20-R20KN-B1 was selected
with shear tension failure as the worst failure case. The beam failed
when load reached the ultimate capacity of 55.25KN (cycle 22). Compared
with results of reinforced concrete before retrofitting, the increase in
ultimate failure load of the beam reached 41.3%.
Difference between failure load capacity
of both GUSMRC and CARDIFRC were insignificant and at 30KN and 40KN,
beams retrofitted with CARDIFRC strips were slightly larger than those
of beams retrofitted with GUSMRC concrete strips in terms of ratio of
mid-span deflection of beams after retrofitting to before retrofitting
This study proves that GUSMRC can effectively serve as a good retrofitting material.
Figure Legend :Procedures for bonding the retrofitting GUSMRC strips. (a)1st step (b) 2nd step
(C) Last step for this type of retrofitting
(d) Last step for this type of retrofitting Figure Legend 2: Casting of GUSMRC strips for retrofitting
Figure Legend 3: Steel fiber distribution inside GUSMRC strips
About The Author
Majed A. A. Aldahdooh
was born in Palestine in 1987. He received the B.Sc. degree in civil
engineering from the Islamic University of Gaza (IUG), in 2009, the
M.Sc. & Ph.D. degrees in structural engineering from the Universiti
Sains Malaysia (USM), in 2011 and 2014. Respectively. He is currently an
Assistant Professor at the University of Buraimi, Sultanate of Oman.
His main areas of research interest are
structural design, structural retrofitting, concrete technology and
structural health monitoring. Along with his experience in teaching and
research; he has several awards including the Ph.D. Fellowship from the
USM (2011-2014), the best Ph.D. research award from the USM (2014) and
several awards for the excellent achievement in journal publications
with high impact factor.
About The Author
Norazura Muhamad Bunnori (PhD) has
been involved in Acoustic Emission (AE) technique and concrete
technologies since 2004 while she was pursuing her PhD study at Cardiff
University, Wales, UK. She was graduated from Cardiff University in 2008
and continues with the AE and concrete research areas at Universiti
Sains Malaysia (USM), Malaysia. Currently she is working as an Associate
Professor at School of Civil Engineering, USM since 2009.
The research covered several topics of
AE applications and analysis (quantitative and qualitive) and concrete
technologies. The aims are to continue the AE study especially in
Structural Health Monitoring (SHM) and concrete technologies research
areas and to discover more in these potential areas. The passion towards
AE and concrete are deep and she believes that there are a great number
of information can be studied and discovered.
About The Author
Dr. Megat Johari is
presently a professor at the School of Civil Engineering, Engineering
Campus, Universiti Sains Malaysia 14300 Nibong Tebal, Pulau Pinang,
Malaysia. He specializes in Concrete Materials and Technology. He has
been teaching Concrete Technology, Civil Engineering Materials,
Construction Technology and Structural Retrofitting Technology courses.
He obtained his PhD and MSc (Eng)
degrees from Leeds University in 2001 and 1996, respectively, and BSc
degree from Ohio Northern University in 1990. He has successfully
supervised and co-supervised more than twenty Master and Phd students,
where many of them were international students. He has authored and
co-authored more than 70 papers, which have been published in refereed
journals and proceedings. The published papers have received more than
700 citation based on scopus.
He has served as manuscript reviewer for
many international journal such as Construction and Building Materials,
Cement and Concrete Research, Materials and Structures, Journal of
Hazardous Materials, International Journal of Environment and Waste
Management, Journal of Thermal Analysis and Calorimetry, Journal of
Civil Engineering and Management and a few other international journals.
Dr. Megat Johari is currently serving as
editorial board member for Malaysian Construction Research Journal and
Journal of Civil Engineering, Science and Technology. He has been
actively involved as speaker in seminars and short courses related to
concrete durability, assessment, maintenance as well as repair and
strengthening. Besides, he has undertaken many testing and consultancy
works related to evaluation of concrete in existing structures.
About The Author
Ali S. Alnuaimi, Associate
Professor in Civil and Architecture Engineering Department, Sultan
Qaboos University, Oman. Dr. Ali earned his Ph.D. from Glasgow
University, UK and his M.Sc. from University of Southern California,
USA.
His research expertise focuses on
structural design and analysis and estimating construction cost. He
published more than 42 refereed journal papers and 33 conference papers.
He supervised/co-supervised more than 30 BSc, 10 MSc and 3 PhD research
projects. Dr. Ali has vast industrial experience as civil and
structural engineer as well as director of projects and maintenance.
About The Author
Ahmad Jamrah is a full
professor of civil and environmental engineering with the Department of
Civil Engineering, University of Jordan in Amman, Jordan. Dr Jamrah is
currently the Dean of the College of Engineering at the University of
Buraimi in the Sultanate of Oman. Dr Jamrah teaches and conducts
research the areas of civil and environmental engineering.
Journal Reference
Majed. A.A. Aldahdooh1, Muhamad Bunnori2, A. Megat Johari2, Ahmad Jamrah1, Ali Alnuaimi3. Retrofitting of damaged reinforced concrete beams with a new green cementitious composites material, Composite Structures, Volume 142, 2016, Pages 27–34.
Increased discharge of greenhouse gases
is now a bigger menace to the environment especially in building sector
and thermal bridges which causes adverse heat transfer leading to
reduction in the insulation performance of the buildings. So,
indispensable green building policies have started preferring zero
energy utilization methodologies thereby resulting in improving
insulation performance.
There have been lots of studies about
the heat losses through different thermal bridges in combination with
several walls to evaluate the energy utilization and the insulation
performance.
Lately, curtain walls have admired as
the envelope of high-rise buildings. For curtain walls, metals with a
low thermal resistance are used for the main components. In many
countries, including Korea, the non-vision parts of curtain walls are
vital to meet a required U-factor (thermal transmittance) of walls, as
spelled out in the building codes. Curtain walls for reducing thermal
bridges are needed to deal with the enriched insulation performance
design criteria to be realistic.
Henceforth researchers led by Professor
Seung-Yeong Song from Ewha Womans University in South Korea suggested
three possible cases that substitutes thermal bridges in steel truss
metal panel curtain walls. In this metal panels are counterfeited by
covering six faces of insulation with metal. Then they are fixed to the
truss and they are compared for its economic feasibility and thermal
functioning through three-dimensional steady-state heat transfer
simulations.
In prevailing system, Bracket-based
fixing method is extensively preferred which makes construction more
convenient. The metal panels can be fixed at only two points when the
size of horizontal metal panel is less than two meters. If it exceeds
two meters, then the metal panel can be fixed at more than three points.
For these types, both vertical and horizontal trusses are needed. For
steel truss metal panel curtain wall systems, the main linear thermal
bridges occur at the vertical and horizontal joints between the metal
panels, where the insulation is non-continuous.
Slim metal panels (Vacuum insulation
panels) used for designing purpose are susceptible by sharp objects. In
order to protect and assuage linear thermal bridges at the joints,
insulation is done by 2 layers by phenolic foam and vacuum insulation
panel. The front and rear surfaces of a metal panel are made of steel
sheet. The upper, lower, right, and left edges of the metal panel are
formed of aluminum moldings in which there is a groove for inserting the
bracket. Polyurethane thermal breaker is amalgamated into the aluminum
molding.
The researchers suggested the first
possibility case which is described as follow: The length of the
prevailing aluminum molding is reduced by one-third to lighten linear
thermal bridges resulting from the aluminum moldings at the joints
between metal panels. The remaining two-third of the metal panel
thickness was fitted with a PVC-foam pad to ensure air-tightness between
the metal panels and to prevent the exposure of insulation in the metal
panel.
In the second possibility case, a
thermally broken bracket replaces the aluminum bracket of first case.
The difference between the thermally broken bracket and the aluminum
bracket is the polyurethane thermal breaker which is not inserted into
the thermally broken bracket. It will reduce the trappings of point
thermal bridges caused by brackets.
In the case of third possibility, its
aluminum molding is same as to second possibility except that a
polyurethane thermal breaker is inserted into the molding to further
reduce the heat loss. They used Midas Information technology – a
structural analysis program to investigate the structural performance of
the thermally broken bracket. The insulation performance is evaluated
using a three-dimensional steady-state heat transfer simulation program
which is used to solve heat equation.
Finally, after analysis of annual energy
costs, evaluation of economic feasibility the validity of the simulated
results was investigated by comparing the authors’ alternatives and
existed cases to the mock-up test results. In addition to this, heating
and cooling energy uses were also calculated by considering the
efficiency of the heating and cooling system. With all these analyses,
this study finally brought up a beneficial and green zero energy
building infrastructure designs that reduces linear bridges, which is
feasible and cost effective.
About The Author
Seung-Yeong Song, Professor, Ewha University, Seoul, South Korea.
The corresponding author of the paper,
Dr. Seung-Yeong Song, is currently a full professor in the Department of
Architectural Engineering at the Ewha University, Seoul. Professor Song
received his BS, MS and Ph.D degrees from Seoul National University and
was a visiting scholar at the University of New South Wales, Sydney.
He has published more than 120 technical
papers in peer-reviewed scientific journals and several research
monographs. He is currently leading several research groups on the
building energy, funded by the Korean Government, as a principal
investigator.
Journal Reference
Jin-Hee Song , Jae-Han Lim , Seung-Yeong Song. Evaluation of alternatives for reducing thermal bridges in metal panelcurtain wall systems.Energy and Buildings,Volume 127, 2016, Pages 138–158.
Department of Architectural Engineering, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, South Korea
Civil Engineering is one of the broadest and
oldest of the engineering disciplines, extending across many technical
specialties. Civil Engineers plan, design, and supervise the
construction of facilities essential to modern life like space
satellites and launching facilities, offshore structures, bridges,
buildings, tunnels, highways, transit systems, dams, airports, harbors,
water supply system and wastewater treatment plants. A civil engineer is
responsible for planning and designing a project, constructing the
project to the required scale, and maintenance of the project. A civil
engineer requires not only a high standard of engineering knowledge but
also supervisory and administrative skills. What does a Civil Engineer do? Civil engineers are involved in the
design and building of highways, bridges and tunnels, schools,
hospitals, airports and other buildings, sewage systems and water
treatment facilities. Most structures, large and small,
require the help of a civil engineer whether in the designing, planning
or managing of the project. Civil engineers also help to preserve
our environment by assisting in the cleaning up of existing pollution
and planning ways to reduce future pollution of our air, land and water. What is the future for a Civil Engineering graduate? Civil engineers are employed in all
the major construction projects carried out by the state or central
government like the public works departments (PWD), the railways and
military. Civil Engineers are mostly required in private construction
and real estate companies as project engineers. Civil Engineers can find
the opportunities in any of the following category As Project Engineer (Construction),
responsible for planning, building large structures such as power
plants, cement factory, over bridges etc. Structural design engineer, to design the large structures Computer Aided Design Engineer, to design the structural members using advanced CAD Packages As Environmental engineer, involving
in environmental impact assessment, water resources management,
pollution control, waste management or the planning and design of
engineering facilities to minimize their impact on the environment Research and Development Engineer, researching in advanced, cost effective & pollution free construction materials Urban planning engineer, to plan for
housing colonies, industrial layouts , water & sewage systems for
urban / semi-urban areas Scope for Higher Education
After graduation as a B.E / B.Tech in Civil Engineering one can look for M.E / M.Tech / M.S in any of the following areas Structural
Construction
Fluid Mechanics
Materials
Environmental
Water Resources
Geotechnical
Coastal
Transportation
Geo-Informatics
Urban planningWho should opt for Civil Engineering?
If one likes,
Construction, Building Structures, Drawings, Planning for house / layouts, Natural resources such as water resource
Civil
engineering has always readily adopted new technologies, using
innovations like suspension systems to build bridges and GPS to plot new
roads. And as technology continues to evolve, we can expect that the
civil engineering field will only keep incorporating this new technology
in increasingly creative ways. In fact, it already is. New technologies
– those that have been released within the last 5 years – are about to
change the civil engineering field and allow innovations previously not
possible. So what are some of the big technological advances we can
expect in civil engineering this year? Here are just a few developments
that are likely to unfold.
Drones: Advanced Mapping and Scanning Capacities for More Accurate Visualizations
Civil
engineering is ripe with applications for unmanned aerial vehicles,
which can aid in scanning and mapping work sites as well as capturing
photos and videos for promotional purposes. UAVs often represent a
cost-saving measure for businesses that need aerial mapping, as a drone
doesn't require a pilot, but rather, a programmer. UAVs are also easy to
program to fly multiple times around the same worksite, which means in
the future, firms will be able to capture a variety of images and videos
while the project is being completed – and that will enable firms to
better manage project progress.
UAVs will also revolutionize civil
engineering through the use of photoscanning, an image capture process
that uses photos (rather than lasers) to capture images. Photoscanning
captures not just the ground surface, but also buildings, plants,
benches, and other nearby structures – and represents them in three
dimensions. With these advanced capabilities, drones will allow for more
accurate and more interactive 3D representations of civil engineering
projects.
The primary disadvantage of drone use in civil
engineering is the initial capital expense required to purchase drones
and train pilots, however, the cost is expected to decline over time.
There are also potential issues involving FAA regulations, citizens'
right to privacy, and how liability insurance would address drone usage.
3D Printing: Marrying Design and Construction
3D
printing is gaining a lot of ground not just among hobbyists, but also
in business – and with 3D printers coming down in price each year, it's
not long before we'll see them used in civil engineering. 3D printing
offers benefits for both design and construction, essentially tying the
two processes together. With 3D printing, it's easy to design custom
construction supplies and then build them using nearly any kind of
material imaginable. In fact, 3D printers are already in use in
construction projects in Europe. Dutch construction company Heijmans –
most well known for its "smart highway" and its glowing bicycle paths,
which use luminescent paint to clearly mark road lanes at night – has
created the world's first 3D-printed bridge in collaboration with
startup MX3D and designer Joris Laarman. The bridge, which was first
designed in October 2015, will span across the Oudezijds Achterburgwal
canal when it is completed in 2017.
MX3D's 3D printer, though,
isn't like those that we've traditionally seen. Rather than a desktop 3D
printer, MX3D's technology consists of a set of large mechanical arms
that hold a torch-like tool for welding. These robot arms build 3D
objects in an open warehouse space rather than inside a box as most 3D
printers do. The arms can also print in all directions, unlike typical
3D printers, which allows for much more creativity and variability in
the design stage. Heijmans Innovation Manager Jurre van der Ven says
that 3D printing joins design and construction into a single process,
rather than two separate processes as has traditionally been seen in
construction. Van der Ven notes that this change will require site
managers and designers to start looking at the design process in a new
way.
However, 3D printers do pose several challenges for civil
engineering. First and foremost, 3D printers are limited in the kinds of
materials they can print – for instance, 3D printers that can print
circuit boards are still in development and may not be ready for
commercial use for several years. 3D printers also pose a threat to
manufacturing jobs, and training staff to use 3D printers may require a
significant capital investment.
PlasticRoad: Improving the Durability and Lifespan of Our Roads
Plastic
is one of the most commonly recycled products, with plastic materials
often being recycled into bottles, bags, toys, containers, and much
more. But now, a Dutch company is attempting to recycle plastic into
something much larger: Roads. VolkerWessels is a Dutch construction firm
that is preparing to build a PlasticRoad in Rotterdam. While
VolkwerWessels' PlasticRoad is still only a concept, it's becoming quite
popular in Holland, where 96 million tons of carbon dioxide are
released into the air through road building and maintenance alone.
VolkerWessels expects that its PlasticRoad will reduce greenhouse gas
emissions while making roads stronger and increasing their lifespan.
Holland's
infrastructure industry expects that these new roads will radically
change the way Dutch development occurs. Relative to laying an asphalt
road, building a road out of plastic is significantly faster, and (at
least in theory) could take as little as just a few weeks. The
PlasticRoad also allows for easy infrastructure upgrades, as the road is
hollow, which enables city planners to run pipes and wires inside the
road itself. Civil engineers say the road's hollow cavities may also be
useful in draining floodwater in the event of rainstorms. Should
Holland's plan succeed, it would serve as a viable proof of concept that
could forever change the way civil engineers all over the world
approach road building.
There are, however, concerns about the
plastic roads that Holland plans to build. Environmentally, there are
concerns that the plastic may leach into the soil and harm the local
flora. The road's components are also somewhat volatile, and exposure to
chlorine will cause the road to give off hydrogen chloride – a
colorless gas that, when exposed to atmospheric humidity, turns into
hydrochloric acid. When it becomes sufficiently concentrated,
hydrochloric acid forms an acidic mist that can cause irreversible
damage to human tissue – and if it is combined with an oxidizing agent,
hydrochloric acid synthesizes into toxic chlorine gas. That means the
engineering process will require stringent safety protocols in order to
protect the on-site crew, and the materials engineers responsible for
the plastic road will need to create a safeguard or additional
waterproof layer that prevents leaching and exposure to chemicals.
Holographic Computers: Giving More Accurate Information to Engineers in Real Time
The
next revolution in wearable tech is here, and it's going to forever
change information management and communication processes in the civil
engineering industry. Microsoft has been promoting its new HoloLens
technology for over a year, escorting the world's most respected
technology journalists to a secret underground bunker at the company's
Redmond campus for tightly controlled product demonstrations.
HoloLens
is a mixed reality headset that layers 3D holograms over physical world
images in order to convey helpful information to the wearer. Using the
HoloLens, civil engineers can see digital input drawn over physical
objects, share that input with collaborators via Skype, fine-tune
designs in 3D, and explore designs in real time. A variety of businesses
are currently using Microsoft HoloLens to alter the way production
happens. Volvo, for instance, is using HoloLens technology to design and
configure its vehicles in completely new ways. Meanwhile, NASA's Jet
Propulsion Laboratory is planning to use the HoloLens to make
holographic representations of the Mars landscape based on Mars Rover
images. Currently, businesses in the architecture and construction
industries are piloting the HoloLens and developing innovative new
processes that leverage 3D holographic models to improve the design
phase.
However, the HoloLens does come with certain disadvantages.
The headset could serve as a workplace distraction that hinders
productivity. The prototype version also has a very limited field of
view, allowing augmented reality vision of only certain objects.
Contactless Security Cards: Improving on RFID to Boost Security
Site
security is always a priority, and with technology evolving, site
managers need more and more security measures at their disposal. The
next big thing in site security is contactless security cards. These
cards can be programmed with individual profile information to uniquely
identify each cardholder, and can give users access to secure offices,
secure parking, and even computer networks. The great advantage that
these smart cards offer is that security becomes much easier to manage.
Employees can check themselves into and out of the worksite with just a
swipe of a card, and managers have a turnkey security solution that
doesn't require their constant presence. However, security cards do
present certain disadvantages.
Firstly, security cards can be lost
or stolen, unlike a memorized four-digit security code. That means
security cards that are reported as stolen or lost will need to be
immediately deactivated, which increases the amount of administration
required. Card-based site access systems are also vulnerable to hacking,
just as most security systems are. Hackers can copy RFID information
using an RFID scanner by simply standing near people with privileged
access, and site workers won't even know their card has been copied.
Civil
engineering is a rapidly changing industry, with new technologies
constantly arising to challenge established norms and revolutionize
traditional practices. These major technology trends are expected to
shake up the industry yet again in 2016, so watch for civil engineers to
start incorporating these tools in projects.
