STUDY ON STRENGTH OF CONCRETE USING VARIOUS COARSE AGGREGATES, PART-17

5.4.3.2 Test specimen

The test specimen shall confirm to all applicable requirements. The specimen shall have a test span within 2% of being three times its depth as tested. The sides of the specimen shall be at right angles with the top and bottom. All surfaces in contact with load-applying and support blocks shall be smooth and free of scars, indentations, holes or inscribed identifications.

5.4.3.3 Procedure

First we turned the test specimen on its side with respect to its position as molded and center on the bearing blocks. The loading system is centered in relation to the applied force. Then we brought the load applying blocks in contact with the surface of the specimen at the third points between the supports. The load may be applied rapidly, up to approximately 50% of the breaking load. Therefore the load is applied continuously at a rate which constantly increases the extreme fiber stress, until the rupture occurs.

Fig No. 5.1: Beam specimen for flexure test.

Fig No. 5.2: The failure pattern of beam after rupture.