Important Points For Civil site Engineer

Basic Points

A)     Bricks

1)      Bricks should be soak in water for 1 hour and spary water before use.

2)      For masonary work – 1 part cement and 6parts sand.

3)      The bricks should be laid alternate header and stretcher pattern

For block only stretcher pattern

The vertical joints should be staaaered

4)      The joints in bricks bulky filled with morter of 10-12mm

5)      For half partition bricks wall or 100mm thik wall place 6mm diameter rebar in every 4^th course

6)      The masonary wall should not raise 1 m height in day.

7)      Masonary wall cured for 10 days.

B)     Aggregate

1)      The size between 4.75mm to 80mm are coarse aggregate

2)      The rougn and non glacy surface aggregate are considered best for construction

3)      Angular aggregate assure high compressive strength in concreate because of the inter locking the angular aggregate due to their hisher specific surface area .

4)      The aggregate should not absorb water more than 10% of their weight (after 24 hr)

5)      Flaky/ thin, elongate / long aggregate not more than 35% by weight of total quantity.

6)      For RCC works 20mm and down size of aggregates.

7)      For 20mm and 10mm the combined ratio is 60:40 or 70:30

Development length:

“The embedded length in concrete is called development length. The minimum length of steel bars necessary on either side od section to develop bond is called as development length.”

Note: for HYSB steel bars increase value for mild steel by 60%

Overlapping length:

The lap of bar needed to transfer the stressen to other bar. Lap length is provided for overlapping two rebars in order to salely transfer the load from one bar to another

1)      Beams and slabs: 60d

2)      Column                : 45d

Bend:

The anchorage value of bend shall be taken as for each 45degree bend, 4 times diameter of bar to maximum upto 10 diameter of bars