Reinforced Concrete and Structural Steel: A Comparative Analysis

This report provides a comprehensive comparison between reinforced concrete and structural steel, two fundamental materials in civil engineering and building construction. It begins by detailing the manufacturing processes of both materials, including the preparation of cement for concrete and the fabrication of steel structures. The report then explores the testing methods used to assess the structural integrity and durability of both concrete and steel, such as slump tests, compressive strength tests, and various non-destructive tests. Furthermore, it outlines the advantages and disadvantages of each material, considering factors such as rigidity, cost-effectiveness, maintenance requirements, and resistance to fire and water. The report also discusses the application of concrete encased structural steel, highlighting their combined benefits in high-rise buildings and other composite structures. Overall, this report aims to provide a clear understanding of the properties, applications, and comparative advantages of reinforced concrete and structural steel in the context of modern construction.

Reinforced Concrete
Concrete is manufactured by mixing aggregates like crushed stone, gravel and sand
with a binding agent like cement, water and chemical agents. When water is added to cement,
cement hydrate crystals are formed and the crystals lock the gravel and cement together. This
interlocking provides the necessary strength for concrete and water provides for the chemical
reactions and hydrates the cement. The concrete gains strength and hardens for at least
another 5 years. (ACI committee 116, 1967). The composition of concrete could be varied to
produce concrete that sets and weathers very well, appears different in color or flows quicker.
Manufacturing of reinforced concrete is fairly simple but in order to understand the
procedure first we should know how concrete is manufactured as reinforced concrete is
nothing else other than concrete with steel reinforcements. The first process in the
manufacturing of concrete is the preparation of Portland cement which is processed by drying
and then powdering alumina, silica and limestone into fine powder and mixing them together
in definite proportions (Reynolds, et al, 2008). It is then preheated, calcined and burned at
2550º F in large rotary kiln to form clinker, which is then cooled and grinded in a rotating
drum to form Gypsum which consists of tetra-calcium alumino-ferite, tricalcium aluminate,
decalcium silicate and tricalcium silicate and this is called cement (McCormac and Brown,
2014).
This cement is then mixed with crushed stone, gravel, sand, water, fibers and
admixtures so as to form a uniform blend. Fibers are added using hand laying, impregnating,
premixing or direct spraying techniques with the help of a dispersing agent like silica fume.
Now this concrete is transported to the work site using pumps, buckets, wheelbarrows or
special trucks. The next step would be placing and compacting, but during the manufacturing
of reinforced concrete this step is slightly modified by casting the wet concrete around
reinforced steel bars. The concrete is uniformly placed inside the formwork using bull floats
and magnesium floats. The surface of concrete is smoothened using trowels, float blades,
edgers, brooms and polishers.
The final step is curing, where once the compacted concrete should be cured in order
to make sure that the concrete does not dry quickly as the strength of concrete depends on the

moisture level while it hardens. Concrete has good compressive strength but poor tensile
strength and steel reinforcement helps to improve the tensile strength of concrete (Skalny and
Mindess, 1989). Steel is preferred for reinforcement because the expansion and contraction of
steel due to heat and cold is same as that of concrete (Neville and Brooks, 1987). The steel
bars are held firmly inside concrete because they are made by twisting strands with ridges or
nobbles so as to eliminate the risk of slippage inside the concrete.
Reinforced concrete is subjected to a lot of tests to evaluate its structural, fire and
safety integrity. The structural integrity of concrete is evaluated based on the following test,
slump test is used to find out the workability of concrete, a compressive strength test is
performed to determine the compression strength of concrete, initial surface absorption, rapid
chloride ion penetration, water absorption and water permeability tests are performed to find
out the durability of concrete. Then there are tests for determining the density, compaction
factor, air content, flow, vebe time, static and dynamic modulus of elasticity, flexural strength
and tensile splitting strength of concrete. All tests are performed as per BS 1881. Some of the
nondestructive tests used to evaluate concrete are as follows.
 Concrete Cover Measurement by Laser Based Instrument.
 Core Extraction for Compressive Strength Test.
 Ultrasonic Pulse Velocity (UPV) Test.
 Rebound Hammer (RH) Test.
 Ingredient Analysis of Concrete Core.
 Combined UPV & RH Test.
The advantages of using reinforced concrete in building construction are as follows.
 Use of reinforced concrete gives rigidity to the building.
 The compressive strength per unit cost of reinforced concrete is lower than similar
materials.
 The erection of reinforced concrete does not require highly skilled labor as compared
to similar materials such as structural steel.
 It requires very low maintenance.
 It can resist fire and water better than similar materials as it suffers only surface
damages in case of a fire outbreak.

 Most of the materials used in the manufacture of reinforced concrete are relatively
inexpensive such as water, gravel and sand and it requires relatively small amounts of
the expensive reinforcing steel and cement.
 It can be manufactured in a variety of shapes like shells, columns, beams, slabs and
arches.
 As far as piers, walls, basement, floor slabs and footings are concerned reinforced
concrete is the only economical option.
 It has very long service life so it could be used almost indefinitely without any
decrease in its load carrying capability. As cement takes years to solidify the strength
of concrete only increases with time.
The disadvantages of using reinforced concrete in building construction are as follows.
 In order to set concrete in place formworks are required and without this formwork
concrete would not harden properly. Additional shoring is required to keep the
formwork in place for floors, walls and roofs until the structure attains the required
strength to support itself.
 The tensile strength of concrete is low and therefore it requires reinforcement.
 Large structures tend to be heavier due to the low strength per unit weight and this
increase in weight may bend large structures. In order to reduce the weight of
concrete lighter materials could be used but this in turn increases the cost of
construction.
 Placing and Curing of concrete is usually not controlled properly resulting in
unevenness.
 Concrete structures will be very large because of the relatively low strength per unit
volume (Mindess, 1991).
 If the concrete is not mixed proportionately then its properties may vary and it would
not meet the desired target.
 The cost of formworks is high which in turn increases the cost of construction.
Structural Steel
The process of manufacturing steelwork to form the structural frame by assembling
and jointing individual steel components is known as fabrication. The entire steel structure is

made from locally available standard sections, protective coatings and bolts. The
effectiveness of steel construction depends on the efficiency of fabrication and erection.
Structural engineer holds the responsibility of erection and fabrication of steel structures.
Structural steel fabrication can be executed on site or in shop. Fabrication completed
in shops is specific and of assured quality, whereas fabrication carried out on site is
comparatively inferior (Bowles, 1980). The procedure adopted for on-site fabrication is
similar to that used in shop but the equipment used are less sophisticated and so is the talent
of employees and hence the quality of finished product tends to be fairly inferior. The type of
fabrication determines the significance and sequence of operation followed for fabricating
structural steel. The sequence of procedures followed during structural steel fabrication is as
follows (Brockenbrough and Frederick, 2011).
 Cleaning the Surface is used to eliminate mill scales before the procedure of
fabrication starts. Cleaning can be carried out either by hand or manually, but
fabrication shops prefer blast cleaning. Blast cleaning is carried out either by
compressed air or by centrifugal impeller for removing rust and roughening the
surface before applying coating on the surface. Other methods of cleaning used by
fabrication shops are flame cleaning using oxy-acetylene torch and by immersing
steel in acids.
 Cutting the steel to required lengths follows surface cleaning and this process is
carried out with the help of any of the following procedures cropping and shearing
using hydraulic shears, cold sawing, arc plasma cutting using an electric arc, burning
or flame cutting using propane like gases.
 Drilling and Punching used to punch holes of desired size in flanges and webs of the
steel components.
 Rolling, Bending and Straightening of the steel components is the next procedure in
fabrication. Straightening is done by gag pressing, pattern heating is carried out to
remove misalignments.
 Reaming and Fitting the steel components is done temporarily using bolts, rivets and
welds. Riveting is best done manually.
 Proper fastening using bolts and rivets gives strength to the entire structure.
 Finishing is one of the final steps of fabrication and it is carried out to transmit the
bearing load so as to support each other. It is carried out using milling or sawing.
 After finishing the steel surface is treated by coating it with paints or metallic coatings
(Gehringer, 1990).

Structural Steel testing is carried out to ensure the quality of different process in steel
structures (Duggal, 2000). Welding is verified using tests like radiographic examination,
ultrasonic examination, penetration flaw detection test and magnetic particle flaw detection
test. Surface defects such as inclusions and cracks are detected using Magnetic particle test,
sub-surface flaws and thickness are detected using ultrasonic test.
The Bolts in Structural steel is tested for proper tightness and strength, holes are
tested for proper diameter. Load test should be carried out to test any part of the defective
steel structure. Galvanized steel’s strength is evaluated using stripping test. Fire protection
coatings that should be applied on the surface of steel structures should comply with the fire
precaution standards. The thickness of the spray, coatings, boards and way to install the
coating should be tested as per the fire precaution schemes. Investigations should be carried
out to check whether the protections codes and standards are followed or not.
The advantages of using Structural Steel in commercial buildings are as follows.
 It is durable as it can withstand extreme conditions like hurricanes, snowfall,
earthquakes, etc.
 It is cost effective and is lighter than wood, since it is lighter than wood it could be
transported easily and could help in saving fuel which further reduces the cost of
transportation (Gambir, 2013).
 It is sustainable and is environmental friendly as steel could be recycled easily when
its life span ends.
 It is highly versatile as it could be molded into any shape as per requirement and is
therefore it is highly adaptable.
 It could be used to stylize any building and is malleable thereby it provides the
designers the freedom to aesthetically design the interiors.
 Steel is highly ductile and therefore it won’t clink, wrap, distort or buckle easily and
can be converted to a variety of shapes without changing its physical properties.
The disadvantages of structural steel can be listed as follows.
 Steel structures have high support cost due to the process of rusting in steel, costly
paints are required to provide resistance against the formation of rust.

 Steel cannot be shaped toward any path you need and It should be used as a part of
structures in which segments exists.
 Steel provides very low resistance to propagation of flame.
 If steel loses its ductility, then it is prone to brittle breaks.
 If steel of different tensile quality is used, then more pressure forms on steel to more.
Because of which steel tensile properties diagram tumbles down.
 If structural steel is subjected to cyclic loading, then its strength reduces due to
fatigue.
Concrete Encased Structural Steel
The blend of steel and concrete finds application in high rise business structures,
production lines, and also in spans. These materials can be utilized as a part of blended
structural frameworks, for instance concrete centers surrounded by steel tubes and in
composite structures of concrete and steel. Both these materials have nearly same thermal
expansion, perfect blend of qualities with steel effective in tension and concrete in
compression, concrete likewise gives thermal protection and corrosion assurance to steel at
raised temperatures and also limits lateral torsional buckling (Kim, et al, 2011).
In composite beams steel and concrete are interconnected using mechanical shear
connectors. Watchful enumerating and development of precast concrete floor or deck
guarantee sufficient control for the connectors. The utilization of precast deck units
diminishes nearby development operations and evades wet exchanges. The units themselves
are thrown on steel formwork in a shop to guarantee high caliber and little resilience.
The proficiency in structural execution will be most prominent in the event that it is
conceivable to guarantee that the concrete slab and steel part act compositely consistently.
For this reason, all heaps, including the dead weight of the structure, ought to be opposed by
the composite segment. This necessity can be met by supporting the steel pillar until the point
that the concrete has solidified. Such help is known as propping. The quantity of
impermanent supports doesn’t require to be high; propping at the quarter span focuses and
mid-span is by and large adequate (Levy, 2005). The props are left set up until the point that
the concrete slab has created satisfactory resistance.

Diverse development strategies prompt distinctive stress states, force disseminations
and avoidances under administration conditions. Be that as it may, composite beams stacked
up to disappointment fall flat at a similar twisting minute regardless of whether propped or un
propped development has been utilized. Their twisting resistance can be effectively
ascertained by methods for rectangular stress squares.
In composite steel concrete structures, be that as it may, huge extra resistance and
stiffness can be given basically by putting ceaseless reinforcing bars in the slab around the
columns. Total cooperation must be guaranteed by methods for mechanical associations. The
associations must be given at any rate at the section closes and where loads or forces are
acting. They ought to be dispersed over the entire cross-area. Such connectors could be going
studs, shear heads, vertical gusset plates, appropriate sections, or other structural means.
Concrete encased columns have favorable position that they meet imperviousness to
fire necessities with no other insurance. Likewise, they can be effectively fortified by
reinforcing bars in the concrete cover. On account of prefabricated encased columns, the
structural steel segments are created in a workshop and incorporate association plates, welds
and other vital connections. These steel columns would then be able to be transported to
another workshop, where cementing happens. After curing the concrete encasement is
conveyed to the development site.
The most vital component of such an in part encased segment is its inalienable high
imperviousness to fire (Macdonald, 2001). The imperviousness to fire is because of the way
that the concrete part keeps the internal steel parts structural steel and also reinforcing bars
from warming up too quick. The concrete parts are thrown in a workshop or on location
before erection. This method empowers quick development with prefabricated composite
individuals. The concrete between the spines ought to be reinforced by longitudinal bars and
stirrups, and ought to be appended to the web by welded bars, stud connectors, or bars
through gaps.
Not-withstanding the upgraded imperviousness to crippling, fire and nearby buckling
of steel is avoided and the resistance of steel bars against lateral torsional buckling is
altogether expanded (Williams, 2011). These beams additionally have more noteworthy

vertical shear and stiffness under twisting which brings about a diminishment of conclusive
redirection.
Some of its advantages are listed here.
 Comprise of profiled steel decking with an in-situ reinforced concrete fixing.
 The decking not just goes about as perpetual formwork to the concrete, yet
additionally furnishes adequate shear bond with the concrete so that, when the
concrete has picked up quality, the two materials act together compositely.
 In the event that the slab is un propped amid development, the decking alone opposes
the self-weight of the wet concrete and development loads. Consequent burdens are
connected to the composite segment.
 On the off chance that the slab is propped, the greater part of the heaps must be
opposed by the composite area.
 The different shapes give Interlock amongst steel and concrete.
 Decking may likewise be utilized to balance out the beams against lateral torsional
buckling amid development.
 Balance out the working all in all by going about as a diaphragm to exchange twist
burdens to the dividers and columns.
 Impermanent development stack for the most part represents the decision of decking
profile.
 Assurance from flame.
 It is expected to Resist a little axial load.
 To decrease the powerful slimness of the steel part, which builds its imperviousness to
axial load.
Some of the disadvantages are as follows.
 The primary strides of utilizing encased structural steel are curing, casting and
mixing. The majority of this influences the last quality.
 Shrinkage causes split improvement and quality misfortune (Bentz and Jensen, 2004).
 The elasticity of encased structural steel is around one-tenth of its compressive
quality.
 For high rise building the RCC column area is bigger than steel segment as the
compressive quality is bring down on account of RCC.
 The cost of the structures utilized for casting RC is generally higher.

Glass as Architectural Façade
Structural glass facades are utilized as a part of longer traversing applications with an
aluminum extrusion as the primary spreading over component ends up plainly unimaginable.
The structure is uncovered, and accordingly turns into a predominant component of the
façade plan. Great consideration is commonly put upon the craftsmanship and enumeration of
the supporting structure. A steady advancement towards a dematerialization of the facades
have been observed recently and this resulted in the increased utilization of tension
components in the structural framework, prompting the utilization of pure tension based
frameworks like link nets (Button and Pye, 1993). Frameless glass frameworks, frequently
called point-settled or point-supported frameworks, are regularly utilized for a similar reason.
Framed board or stick sort frameworks using aluminum extrusions are additionally utilized
viably in structural glass facades, yet they are integrated in plan with the structural
frameworks that support them, and are considerably different than curtain divider
frameworks. Transparency property has pushed glass to its prominent position as structural
glass façade and is used widely as an architectural material (Behling and Behling, 1999).
Architectural glass is produced from a well-known form of glass known as soda-lime
glass (Compagno, 1999). Various material properties of glass like resistance to high
temperatures and corrosion, transparency and durability combined with tremendous
production limitation and relative ease in the industry, make it an extraordinarily appropriate
material for architectural applications. The glass utilized as a part of structural glass facades,
vary significantly among projects. It is quite often strengthened to yield buoy glass process,
subject to adjustment through some form of secondary processing including value in some
way or the other (Rice & Dutton, 1995). Secondary processes incorporate various blends of
warmth treating, covering, fritting and covering, like others. Level glass can likewise be
bowed for an interesting architectural effect (Loughran, 2003).
Fabrication requirements vary as an element of structural and glass framework sort.
Contingent on the product cost, specification and accessibility, glass may be imported,

presenting strategic and planning issues. The issues and requirements are not trivial, as
consumption, cost of work and quality are determined by the way in which they are managed.
Uncovered steel structures require a phenomenal level of craftsmanship in their fabrication.
Steps should be adopted to properly determine the requirements on the outline side and to
ensure that these specifications are actually met on the manufacture side. Once more, a
portion of the processes and materials used in structural glass facades, are not new by any
methods and are unfamiliar to a significant part of the construction industry, affecting
configuration, erection and fabrication processes (Fleming, 1999).
Advantages of utilizing glass as architectural facade are as follows
 It can be pressed, drawn and blown to any shape and therefore can be utilized for
general coating purposes in doors, windows, shop fronts and workshops.
 Accessible in a range of colors and if the glass sheet in overlaid or protected units are
consolidated, glass changes its appearance and color.
 It can be used in furniture production by overlaying with metal sheet or plywood.
 It is a fantastic insulator of electricity and is therefore difficult to direct an electric
current through it.
 Glass enables natural light to enter the house regardless of the possibility that
windows or doors are shut so accordingly it spares energy and furthermore lowers the
electricity bills, brings out the magnificence of the home, brightens up the room and
helps the inclination of inhabitant (Pellacani and Manfredini, 1991).
 It is completely weather resistance which helps it to withstand the impacts of rain,
breeze or sun without losing its integrity or appearance.
 It can transmit up to 80% of accessible natural sunshine in two directions with no
weathering, clouding or yellowing.
 It is not affected by rust so it does not degrade gradually.
 Glass provides a perfect approach to exhibit a product.
 Glass that transmits, absorbs or refracts light can be made translucent or transparent,
which adds extraordinary magnificence to the building.
 At the point when utilized as a part of the interiors, glass spares space.
 Glass has a smooth lustrous surface so it can be easily cleaned.
 Glass can influence the structure to look more dazzling, advanced and excellent. It is
utilized to accomplish the architectural view for external decoration (Rogers, 2003).

 It is unaffected by water, air, clamor and acids thus it prevents swelling, softening,
alteration in the degree of sparkle, discoloration and blistering, thereby giving
protection against outside barriers. It is also UV stable.
 It is astounding abrasion resistant and therefore it will prevent surface wear caused
due to level rubbing and contact with another material.
 It is 100% recyclable and it doesn't degrade during the recycling process and therefore
glass can be easily recycled without much loss of purity or value.
 It is steady over an extensive variety of temperature so it is utilized in high-
temperature areas where low development is required, cooking tops, wood burning
stoves, high-temperature light lenses and fireplace glass are required.
 Glass is also utilized to manufacture superior liquid crystal displays by utilizing
combination draw manufacturing process and powers electronic device screen
revolution.
Disadvantages of utilizing glass as architectural façade are as follows
 It is affected by external hydrofluoric corrosive thus at some point drawings appear on
glass surface.
 Glass façade building creates a lot of glare which is a major problem.
 Utilization of glass additionally upgrades the cost of security.
 Glass has poor ability to withstand sudden connected loads.
 Glass is highly brittle therefore it breaks easily when it is subjected to stress. Broken
bits of Glass can injure people easily.
 Manufacturing of glass requires high temperatures for processing the raw materials
and is therefore a high energy devouring process.
 It is a costly material which further increases the cost of a building.
 R-value is considered as a standout amongst the most important factors for protection
and Glass has a relatively low R-value because it offers superior transparency of
warmth which is to be adjusted (Nijsse, 2003).
 It is additionally perilous for earthquake proven area.
 It is poor in terms of warmth preservation, thereby increasing the operational cost of
air-conditioners.
 The Glass is influenced by soluble bases particles due to which glass corrodes at a
uniform rate.

 It absorbs warm and consequently go about as a greenhouse and subsequently not
appropriate in hot and warm atmospheres.
Partition Walls and Ceramic Floorings
Partition walls are built to utilize more space to the existing situation and the proper
procedure in which a partition wall should be constructed is as follows. A partition wall
requires wall studs, floor plate and top plate. Wall studs should be divided 16 inch separated,
of focus to focus remove (Brock, 2005). Begin by cutting the floor plate and top plate that
will be utilized on the partition wall. These plates should be made by utilizing long lengths of
wood, twelve or sixteen-foot length. Make sure to quantify the floor plate and recall that it
won't go through an entryway. Once the floor and top plate are cut, stamp the coveted stud
appropriation, sixteen crawls on focus.
Utilizing a chalk line, stamp on the floor where the plate will be introduced. Nail the
floor plate in position. Utilizing a 3/16 masonry bit, bore an opening through the wood into
the concrete. Bore another sledge penetrate openings each sixteen inches along the plate,
close to the focal point of the board. Finish an effect driver. Utilize the effect driver to drive a
three-inch concrete screw into each gap. Since the base plate is connected to the floor, utilize
a ling 2 x 4 to position the top plate specifically over the base plate.
On the off chance that the partition wall keeps running over the joists in the roof, nail
the top plate to every joist. On the off chance that that is not the situation, at that point you
should introduce connecting of 2 x 4 between the joists to give a strong surface that can be
utilized to nail the top plate. Spanning should likewise be introduced on sixteen-inch focuses
and connect them to the joist utilizing two nails on each finish of each crossing over piece.
You can guarantee legitimate arrangement of the top plate by hanging a plumb bob.
To fabricate the partition wall quicker, all studs and top plate should be amassed on
the floor as a solitary piece (Langdon, 1998). By doing this you ought to have the capacity to
nail the top plate straight into the top of each wall stud. Place them around four feet up, end-
on between each stud. Some of the time studs may have distinctive lengths, so in such cases,
introduce the top plate and toenail each stud set up. The privilege toenailing might comprise