What is the primary purpose of providing spacing between reinforcement bars?
A Increase concrete strength
B Improve aesthetics
C Ensure proper bond and compaction
D Reduce cost
Proper spacing between reinforcement bars ensures adequate bond strength between concrete and steel. It also allows for proper compaction of concrete, preventing voids and ensuring structural integrity.
Which of the following is a characteristic of lightweight concrete?
A High shrinkage
B Low thermal conductivity
C High density
D High compressive strength
Lightweight concrete has low thermal conductivity, making it suitable for insulation purposes. It is made using lightweight aggregates and is used in applications where weight reduction is critical, such as in precast elements.
What is the primary purpose of a cantilever slab?
A Reduce deflection
B Support loads on all sides
C Project beyond supports
D Increase bond strength
A cantilever slab projects beyond its supports and is fixed at one end. It is commonly used in balconies, canopies, and staircases, where it resists bending moments and shear forces without intermediate support.
Which of the following is a common cause of punching shear failure in flat slabs?
A Concentrated loads
B Lateral forces
C Bending moments
D Low reinforcement ratio
Punching shear failure occurs in flat slabs due to concentrated loads, such as columns, causing high shear stresses around the load area. Proper design and shear reinforcement are required to prevent such failures.
What is the primary purpose of a raft foundation?
A Reduce construction time
B Improve aesthetics
C Distribute loads over a large area
D Transfer loads to deep soil
A raft foundation distributes the load of the structure over a large area, reducing the pressure on the soil. It is used in areas with weak soil or where differential settlement is a concern.
Which of the following is a key factor in the mix design of concrete?
A Water–cement ratio
B Column size
C Reinforcement spacing
D Beam depth
The water–cement ratio is a critical factor in mix design, as it affects the workability, strength, and durability of concrete. A lower water–cement ratio generally results in higher strength and durability.
What is the primary purpose of providing hooks in reinforcement bars?
A Increase bond strength
B Ensure proper anchorage
C Reduce deflection
D Improve aesthetics
Hooks are provided at the ends of reinforcement bars to ensure proper anchorage and prevent slippage. They help transfer stresses between concrete and steel, enhancing structural stability.
Which of the following is a common method for structural retrofitting?
A Adding new columns
B Reducing loads
C Increasing water–cement ratio
D Applying fiber–reinforced polymers (FRP)
Structural retrofitting involves strengthening existing structures. FRP wrapping is a common technique that enhances the load–carrying capacity and ductility of beams, columns, and slabs without adding significant weight.
What is the primary purpose of a water tank in reinforced concrete design?
A Improve aesthetics
B Increase soil strength
C Store water
D Reduce foundation depth
Reinforced concrete water tanks are designed to store water for domestic, industrial, or firefighting purposes. They must be leak–proof, durable, and capable of withstanding hydrostatic pressure.
Which of the following is a key consideration in earthquake–resistant design?
A High shrinkage
B Ductility
C Low reinforcement ratio
D High stiffness
Ductility is crucial in earthquake–resistant design as it allows structures to undergo large deformations without sudden failure. This helps dissipate seismic energy and prevents collapse during earthquakes.
What is the primary purpose of the working stress method?
A Increase ductility
B Ensure ultimate strength
C Reduce deflection
D Limit stresses under service loads
The working stress method ensures that stresses in concrete and reinforcement remain within permissible limits under service loads. It focuses on elastic behavior and prevents excessive cracking or deflection.
Which of the following is a common type of foundation for high–rise buildings?
A Raft foundation
B Strip foundation
C Pile foundation
D Isolated foundation
Pile foundations are commonly used for high–rise buildings to transfer heavy loads to deep, stable soil strata or rock. They provide stability and prevent excessive settlement.
What is the primary purpose of reinforcement detailing?
A Reduce concrete strength
B Ensure proper placement of bars
C Increase shrinkage
D Improve aesthetics
Reinforcement detailing involves specifying the size, spacing, and arrangement of reinforcement bars. It ensures proper load transfer, structural integrity, and compliance with design requirements.
Which of the following is a key factor in the durability of concrete?
A Low compressive strength
B High shrinkage
C Low permeability
D High water–cement ratio
Durability of concrete depends on its ability to resist the ingress of harmful substances like water, chemicals, and gases. Low permeability, achieved through proper mix design and curing, enhances durability.
What is the primary purpose of torsion reinforcement in beams?
A Resist bending moments
B Resist twisting forces
C Improve bond strength
D Reduce deflection
Torsion reinforcement, such as closed stirrups and longitudinal bars, is provided in beams to resist twisting forces caused by eccentric loads or uneven support conditions, preventing structural failure