Question

Q2: Determine the number of 8-inch-high by 8-inch-wide by 16-inch-long concrete blocks required to complete the wall in Figures below. The overhead doors are 10 feet wide by 12 feet high. If lintel blocks are required wherever the #4 horizontal bars are located and above the doors, how many plain blocks and how many lintel blocks are needed for the wall?

Answer 1

The image of the elevation and wall section is missing, so i have attached them.

Answer:

Number of concrete blocks = 1020 blocks

Number of lintel blocks = 240

Number of plain blocks = 780

Explanation:

First of all, we'll find the net area of the wall as follows:

The height of the wall is 17' - 4", so we need to convert it to ft, thus, h = 17' + (4/12)' = 17.33'

So, Gross wall area = 80′ × 17.333' = 1,387 ft²

From the image, there are 4 doors, thus, Area of doors = 4 × 10′ × 12′ = 480 ft²

Thus, Net area = Gross wall area - area of doors

Net area = 1,387 – 480 = 907 ft²

We are told that the block is 8 inches length by 16inches width. Thus, converting to ft; (8/12)ft by (16/12)ft.

So area of one block = (8/12) x (16/12) = 128/144 ft² = 0.88889 ft²

So, number of blocks per ft² = 1/0.88889 = 1.125 blocks

So, there are 1.125 blocks per ft²

Thus, Number of concrete blocks = 907 ft² × 1.125 blocks per ft² = 1,020 blocks

From the image attached, there are five rows of lintel blocks, located at 4′, 8′, 12′, 16′, and 17′-4″. The bottom three rows pass through the doors and are only a total of (80′ – (4 × 10′) ) = 40′ long .

The top two rows are 80′ long. Thus, there is 40 feet (4 × 10′) of lintel block above the doors.

Lintel blocks = (3 × 40′) + (2 × 80′) + 40′ = 320 ft

Number of Lintel blocks = 320′ × 12 in per ft / 16″ = 240 blocks

Number of Plain blocks = 1,020 blocks – 240 blocks = 780 blocks