Midterm exam ( Rebars And Formworks) Flashcards
It’s a steel bar or mesh of steel wires used in reinforced concrete and masonry structures to provide tensile strength and help distribute the load more effectively.
Rebar
What are the type of rebars?
•carbon steel rebar
•stainless steel rebar
•galvanized rebars
•glass fiber reinforced polymer (GFRP) rebar
•epoxy coated rebar
•welded wire fabric (WWF) rebar
•expanded metal rebar
It is one of the most commonly used manufacturing and construction materials in the world due to its strength, adaptability, and affordability.
Carbon steel rebar
This rebar is a type of reinforcing bar made from stainless steel, a corrosion-resistant alloy that contains chromium, nickel, and other elements. This type of rebar is used in concrete structures where corrosion resistance is a primary concern, such as in marine environments, chemical processing plants, and structures subjected to de-icing salts.
Stainless steel rebar
It have a zinc coating that provides corrosion resistance. They are often used in areas with exposure to moisture, such as in bridge decks and highway structures.
Galvanized rebars
It’s a structural ribbed reinforcing bar made of high strength and corrosion resistant glass fibres that are impregnated and bound by an extremely durable polymeric epoxy resin.
Glass fiber reinforced polymer rebar
This a type of reinforcing bar that is coated with an epoxy layer to protect against corrosion and increase durability. The epoxy coating acts as a barrier to prevent the steel from being exposed to corrosive elements
Epoxy coated rebar
It is a prefabricated reinforcement consisting of parallel series of high strength cold drawn or cold rolled wire welded together in square or rectangular grids.
Welded wire fabric rebar
It is commonly used where a considerable thickness of plaster is required, or to reinforce light concrete construction.
Expanded metal rebar
It play a critical role in the strength and durability of concrete structures.
Rebar sizes
The rebar sizes are determined by?
•engineering requirements
•load-bearing capacity
•specific project needs
What are the common rebar sizes?
10mm
12mm
16mm
20mm
25mm
32mm
Rebar replacement :
•SPACING AND COVER REQUIREMENTS
•LAP LENGTH
•SPACING BETWEEN PARALLEL BARS
•DEVELOPMENT LENGTH
•PLACEMENT TOLERANCES
•PROPER FIXING AND SUPPORT
•BENDING AND CUTTING
What are the construction standards and codes?
•PHILIPPINE NATIONAL STANDARD (PNS 49)
•NATIONAL BUILDING CODE OF THE PHILIPPINES (NBCP)
•PHILIPPINE INSTITUTE OF CIVIL ENGINEERS (PICE) CODE OF ETHICS AND STANDARDS OF PROFESSIONAL PRACTICE
•LOCAL BUILDING CODES
•STRUCTURAL ENGINEERING CODES
•RELEVANT INTERNATIONAL STANDARDS
It’s s a mould used to form concrete into structural shapes. Formwork can be made of timber, steel, plastic, or fiberglass.
Formworks
Good formwork system:
- Easy removal and economical
- Less leakage and quality
- Rigidity and smooth surface
- Strength and support
What are the type of formworks?
• timber formwork
• stainless steel formwork
• reusable plastic formwork
• permanent insulated formwork
• stay-in-place formwork
• flexible formwork
It is a Traditional formwork system using timber or plywood sheets.
Timber formwork
Suitable for simple structures and projects with budget constraints.
Timber formwork
It is a Pre-engineered formwork systems that come with integrated components.
Stainless steel formwork
Designed for specific applications and can be quickly assembled.
Stainless steel formwork
It is made of lightweight and durable plastic. Designed for small to medium residential projects.
Re-usable plastic formwork
A lightweight formwork (made from an insulating material) to support concrete walls whilst they are being cast in-situ and which is then left in place as insulation.
Permanent insulated formwork
Used in the construction of load-bearing walls and foundations.
Stay-in-place formwork
The formwork remains in place after the concrete cures, eliminating the need for removal.
Stay-in-place formwork
Innovative formwork that uses fabric or textiles as a mold for shaping concrete.
Flexible formwork
Suitable for creating unique, organic shapes in architecture.
Flexible formwork
Components of a formwork:
BRACES
TIE
STUDS
SHEATHING
WALES
FOOTING
SIDE PLATE
BATTENS
CLEAT
It’s a system of structural members used temporarily to support loads during construction. The forces arising from these loads must be fully resolved, using props or columns
to provide all the support needed for the work under construction such as beams. formwork but are not limited to onlv the above mentioned.
Propping and centring
It’s a Formwork (Shuttering) acts as moulds for pouring concrete
Shuttering
The formation of a sharp nice corner is practically difficult and the concrete at corners is easily chipped and broken into pieces during the removal of concrete formwork. Hence, the provision of chamber could protect the corner from chipping when striking formwork.
Provision of chamber
Fourth step in formwork installation
Cleaning and surface treatment
Allow the concrete to dry before removing the forms. You’ll want the concrete to be hard and strong so that removing the forms does not result in a sagging surface. Allow the concrete to cure overnight.
