DETERMINATION OF COMPRESSIVE STRENGTH OF BRICK
Apparatus: A compression testing machine, the compression plate of which shall have a ball seating in the form of portion of a sphere the center of which coincides with the center of the plate, shall be used. Preconditioning: Remove unevenness observed in the bed faces to provide two smooth and parallel faces by grinding. Immerse in water at room temperature for 21 hours. Remove the specimen and drain out any surplus moisture at room temperature. Fill the frog ( where provided ) and all voids in the bed face flush with cement mortar ( 1 cement, clean coarse sand of grade 3 mm and down ). Store under the damp jute bags for 24 hours followed by immersion in clean water for 3 days. Remove, and wipe out any traces of moisture. Procedure: Place the specimen with flat faces horizontal, and mortar filled face facing upwards between two 3-ply plywood sheets each of 3 mm thickness and carefully centred between plates of the testing machine. Apply load axially at a uniform rate of 1