Construction Test 1 — Questions and Answers

Question 1: Choose one of the following to represent the false statement:

Before making lime mortar, lime should be slaked.
The walls are pointed with lime surkhi mortar.
The only purpose of adding cement to lime mortar is to improve its hydraulic qualities. (Correct answer)
Concrete with a high early strength is typically utilized in cold climates.

Correct answer: The only purpose of adding cement to lime mortar is to improve its hydraulic qualities.

The statement is false because adding cement to lime mortar, creating gauged mortar, serves multiple purposes beyond just improving its hydraulic qualities. Cement significantly increases the mortar's compressive strength and accelerates its setting time. While it does enhance hydraulic properties (ability to set underwater), it also improves overall strength, durability, and reduces shrinkage, making the mortar more robust for various construction applications.

Question 2: If the soil is _______, a pile foundation is typically offered.

Made up
Soaked in water
Compressible
All options are correct (Correct answer)

Correct answer: All options are correct

Pile foundations are a type of deep foundation typically used when the soil near the surface is weak or unsuitable to support the structural loads. This includes conditions where the soil is highly compressible, loosely 'made up' or unconsolidated, or saturated with water, which significantly reduces its bearing capacity. In such cases, piles transfer the building's weight to deeper, stronger soil layers or bedrock.

Question 3: The soil's bearing capacity cannot be increased by

Making sand heaps
Watering the soil's surface (Correct answer)
Ramming dirt with crushed stone
Removing subsurface water

Correct answer: Watering the soil's surface

Watering the soil's surface generally decreases its bearing capacity, especially for cohesive soils like clay, by increasing the moisture content and reducing shear strength. Conversely, methods such as making sand heaps (implying compaction or replacement), ramming dirt with crushed stone (compaction and reinforcement), and removing subsurface water (reducing pore pressure) are all effective techniques used to improve soil bearing capacity and stability.

Question 4: When drilling in ________, rotary drilling is the fastest method.

Clay soils
Sandy soil
Rocky soils
All of these (Correct answer)

Correct answer: All of these

Rotary drilling is a highly versatile and efficient method for creating boreholes in a wide range of geological conditions. It operates by rotating a cutting bit that grinds or shears through the material, making it effective in various soil types including soft clay, loose sandy soil, and even hard rocky soils. Its adaptability and speed make it a preferred choice for many drilling applications.

Question 5: For beams and slabs, concrete slump should range from ________.

30 to 125 mm (Correct answer)
40 to 100 mm
35 to 125 mm
45 to 100 mm

Correct answer: 30 to 125 mm

Concrete slump is a measure of its workability, indicating the consistency of the fresh concrete mix. For structural elements like beams and slabs, a slump range of 30 to 125 mm (approximately 1 to 5 inches) is generally recommended. This range ensures the concrete is workable enough to be placed and compacted effectively without excessive segregation, while still maintaining adequate strength and durability after hardening.

Question 6: A cross joint is _______ to the plumb line when it is aligned.

Vertical line
Bed block
Perpendicular (Correct answer)
Lintel

Correct answer: Perpendicular

In masonry construction, a cross joint (also known as a bed joint) is the horizontal mortar joint between courses of bricks or blocks. When properly aligned and constructed, this joint should be perfectly perpendicular to the plumb line, which represents a true vertical. This ensures that the masonry units are laid level, contributing to the wall's structural integrity and aesthetic straightness.

Question 7: _______ is a protruding element that is typically used to support a truss.

Frieze (Correct answer)
Cornice
Lintel
Coping

Correct answer: Frieze

A frieze, in architectural and construction contexts, can refer to a horizontal band or element that often serves both decorative and structural purposes. While commonly known for ornamentation, a structural frieze board can be specifically designed and used to support the lower edge of a truss or roof structure, effectively transferring the roof loads to the supporting walls below.

Question 8: ________ are the best kind of piles for soft soil with little resistance to the flow of concrete.

Franki pile
Raymond pile
Vibro pile (Correct answer)
Simplex pile

Correct answer: Vibro pile

Vibro piles are particularly well-suited for soft soils with low resistance to concrete flow because they are driven into the ground using high-frequency vibration. This vibratory action helps to compact the surrounding soil, creating a denser plug and minimizing the loss of concrete into the ground during the casting process. This ensures a more consistent and structurally sound pile formation in challenging soil conditions.

Question 9: Only after ____ days may the formwork on the underside of the slabs be removed.

5
7 (Correct answer)
12
14

Correct answer: 7

The removal time for formwork is critical and depends on the concrete's strength gain, which is influenced by factors like mix design, temperature, and curing. For the underside of concrete slabs, a minimum period of 7 days is generally recommended before formwork removal. This allows the concrete to achieve sufficient strength to safely support its own weight and any subsequent construction loads without excessive deflection or damage.

Question 10: For spans, couple roof is used.

less than 8 m, but 6.5 m
6 to 6.5 m but not less than
less than 3.5 m (Correct answer)
less than 5 m, but 2.5 m

Correct answer: less than 3.5 m

A couple roof is a basic roof structure consisting of two rafters leaning against each other at the ridge and supported by the walls at the eaves. Due to its simple design and the outward thrust it exerts on the walls, it is only suitable for relatively small spans. Typically, couple roofs are used for spans less than 3.5 meters (approximately 11.5 feet).

Question 11: The depth of soil exploration for large embankments and dams should not be less than _______.

1/2 h
2 h (Correct answer)
h/4
h/8

Correct answer: 2 h

For critical structures like large embankments and dams, thorough soil exploration is essential to assess stability and potential settlement. The depth of exploration must extend significantly below the base of the structure to identify all relevant soil layers and their properties. A common guideline is that the depth should not be less than 2h, where 'h' is the height of the embankment or dam, to adequately investigate the stress influence zone.

Construction Test 1

Choose one of the following to represent the false statement: