6.1 Various options are given as possible answers to the following questions - NSC Civil Technology Construction - Question 6 - 2023 - Paper 1

D - A and B only.

A - drop.

B - support light loads.

B - Long-bored piles.

To answer this part, sketch an enlarged base with a concrete plug, ensuring to indicate the symbol for concrete which is typically represented as a filled rectangle or an outlined rectangle with 'C' written inside.

The components of a rib and block floor include:

• Hollow core blocks
• Precast ribs/Pre-stressed ribs
• Steel mat/Wire/Reinforcing mesh/Reinforcing steel
• Spacers
• In-situ cast concrete/Concrete.

Removing the temporary props prematurely can lead to the collapse of the rib and block floor due to insufficient support, causing structural failure and compromising the integrity of the concrete.

In the code:

• 6.5.1 4: Indicates the number of bars in the reinforcement group.
• 6.5.2 20: Denotes the diameter of the reinforcement bar in millimeters.
• 6.5.3 250: Refers to the center-to-center spacing or heart spacing of the bars in millimeters.

The sectional view should include:

• Eight main bars arranged properly in the L-shaped column.
• Stirrup placement indicated correctly.
• Minimum concrete cover specified as per design standards.
• Two labels must be printed, labeling the main bars and stirrups.

To calculate the volume:

1. Dimensions:
   • Length = 7.000 m
   • Width = 6.000 m
   • Height (thickness of blinding layer) = 0.040 m.
2. Volume formula: $ext{Volume} = ext{Length} imes ext{Width} imes ext{Height}$ Substitute values: $ext{Volume} = 7.000 imes 6.000 imes 0.040 = 1.680 m^3$
3. Rounded off: 1.68 m³.