The most important purpose of frog in a brick is to
- AForm keyed joint between brick and mortarCorrect
- BReduce the weight of brick
- CEmboss manufacturer’s name
- DImprove insulation by providing ‘hollows’
Solution
Concept
Primary purpose of frog in building bricks
Formula
NONE
Step-by-step solution
1. A frog is a depression formed on the top face of a brick during manufacturing. 2. When filled with mortar, it forms a keyed mechanical joint between adjacent brick courses. 3. This keyed joint enhances the structural stability and shear resistance of the brick masonry wall. Answer: A
Explanation
A frog is an indentation or depression formed on the top face of a brick during manufacturing. When mortar fills this depression during masonry construction, it forms an effective key that locks adjacent brick courses together. This mechanical keying increases shear resistance and improves overall stability of the wall.
Why the other options are wrong
B) Weight reduction is a minor side effect, not the primary purpose of providing a frog. C) Embossing the manufacturer's name is a secondary branding function. D) Thermal insulation is provided by hollow or perforated bricks, not frogs.
Shortcut
The main purpose of a brick frog is to create a keyed joint for mortar bonding.
Common mistake
Assuming the main function of a brick frog is weight reduction or branding rather than creating a mechanical key for mortar.
Correct answer: A) Form keyed joint between brick and mortar