Construction Technology 2 presentation

1. Structural steel framing is a durable, reliable, cost-effective,
sustainable option for low-rise, mid- rise and high-rise building
projects and typically refers to building frame systems where the
vertical and horizontal structural elements are formed by a
system of structural steel beams and columns.
Question:

2. a) What type of workers are required to erect structural steelwork frame
especially for tallest building.
1) IRONWORKERS
• When building tall structures such as a skyscraper, ironworkers
erect steel frames and assemble the cranes and derricks that
move structural steel, reinforcing bars, buckets of concrete,
lumber, and other materials and equipment around the
construction site.
• Workers also connect steel columns, beams, and girders
according to blueprints and instructions from construction
supervisors. A few also may install precast walls or work with
wood or composite materials.
2) SITE MANAGERS
• Site managers oversee the various construction activities and
coordinate the day-to-day activities on the site.
• They make sure that the building work is finished on time, within
budget and to a high standard, managing teams of workers.
• They schedule contractors and material deliveries.

3. b) List out TWO (2) types of steel section are available in the market.
Support your answer with THREE (3) sketches of each sections.
Hot roll formed sections Cold roll formed sections

4. Hot rolled steel is steel that has been roll-pressed at very high temperatures—over 900˚C, which is
above the re-crystallization temperature for most of the steels.
• Often used for :
• Railroad tracks
• Construction projects
Universal beam Equal Angle Section Channel Section
HOT ROLL FORMED SECTIONS

5. COLD-ROLLED FORMED SECTION
• Cold rolled steel is manufactured at temperatures below its
recrystallization temperature, typically at around room
temperature.
• Because the steel is manufactured at a much lower
temperature, there’s no need to worry about the steel shrinking
or changing form or appearance.
• The cold rolled steel end products like cold finished steel bar
has a much smoother appearance and may have square
corners more accurate in dimension and finish.
• Cold rolled steel is much more preferred in the machining
world where the quality of the steel is an important factor of the
quality of the final product, and the appearance of the steel is
also an important factor.

6. WHY FIRE PROTECTION IS IMPORTANT TO STEEL
STRUCTURE ?
-To keep the temperature of steel below critical temperature
-When a temperature of between 500°C and 600°C is reached, in 90%
of cases steel loses more or less 50% of its loadbearing capacity
-Steel is a heat conductor, its temperature easily rises in case of fire
-Produce a lot of noise before the building collapse
C) Explain why the fire protection is required to apply for the steel
structures. Please suggest TWO (2) suitable methods of fire protection.

7. 1. SPRAY COATING
-expand as much as 100 times the original thickness of the material
-undergo a chemical reaction and expand when subjected to extreme
temperatures
-Aesthetics and suitable exposed to the general public
-Cheapest method
2 types of intumescent coatings
• Soft Char
-fire water vapor (the hydrates) is released, resulting in a cooling effect
remaining char will slow heat transfer to the substrate
• Hard Char
-mostly used for plastic pipe protection but can also be used as exterior
steel fireproofing
-unsuitable for interior spray fireproofing.

8. 2.BOARD CASING
• This system uses materials such as mineral fiberboards ,gypsum board,
fire resistant plasterboard and vermiculite to provide fire protection to
steel.
• There are broadly two families of board protection, lightweight and
heavyweight.
• Lightweight boards are not suitable for decorative finishes .Heavyweight
boards will generally accept decorative finishes and are therefore used
where aesthetics are important.
• Suitable for used in conjunction with ceiling and wall finishes but not
external used.
• Boards are specified in terms of thickness required to achieve the limiting
temperature for a particular section factor.
• Offer a clean, boxed appearance, cost effective and can be applied to
non-painted steel members.
• Strong and durable but also compatible with decorative finishes. Boarded
fire protection system is suitable for steel columns and beams with

9. d) Identify the benefits of using the structural steel frame to high rise
building.
DURABILITY
● Structural Steel is superior in strength and it does not age or decay as
quickly as other construction materials.
● With a much higher strength-to-weight ratio (the strength of a material
over its density) and tensile strength (ability to withstand stress from
tension), structural steel will make for a lighter building that requires a
less substantial and expensive foundation.
● Less maintenance cost.
DESIGN FLEXIBILITY
● The advantages that structural steel offers to the construction sector have
long been recognized by the designers and specifiers. The versatility of
steel gives architects, designer and engineers the freedom to achieve
their most ambitious visions.
● The strength, stiffness, toughness, and ductile properties of structural
steel allow it to be fabricated into an endless variety of shapes.

10. SAVE MONEY
• Steel is durable - requires little maintenance. Minimal
maintenance fees, repairs and replacements.
• Steel is recyclable - if you decide to tear down the building, you
will be able to recycle the whole structural frame without buying a
new one.
FASTER BUILD TIME
• Unlike frames from other materials, steel comes pre-fabricated to a
specific design or size to the site and ready to be installed.
• Highly quality-controlled. Reducing the amount of time spent
assembling something only to find out it needs to be re-
measured, cut and installed again.
ECO - FRIENDLY
• Steel is made from recycled materials and can be recycled at the end of its
lifespan.
• Steel buildings can also be energy efficient. Since parts are pre-engineered,
they are able to fit more exactly, so when they’re combined with proper
insulation, a building is completely airtight. Steel roofing panels can also be
primed to prevent solar rays from heating a building.