REINFORCEMENT SPLICING – AS PER IS 456 -2000 It Is recommended that splices (Lap) in flexural member should not be at sections where the bending moment is more than 50 percent of the moment of resistance; and not more than half the bars shall be spliced at a section. Where more than one-half of the bars are spliced at a section or where splices are made at point of maximum stress, special precaution shall be taken, such as increasing the length of lap and/or using spirals or closely-spaced stirrups around the length of the splice. Notes:- 1. Lap splices shall not be used for bars larger than 36 mm ; for larger diameters, bars may be welded; in cases where welding is not practicable, lapping of bars larger than 36 mm may be permitted, in which case additional spirals should be provided around the lapped bars. 2. Lap splices shall be considered as staggered if the centre to centre distance of the splices is not less th...
WORKABILITY OF CONCRETE - AS PER IS-456-2000 The concrete mix proportions chosen should be such that the concrete is of adequate workability for the placing conditions of the concrete and can properly be compacted with the means available. Placing Conditions Degree of Workability Slump(mm) Blinding concrete; Shallow sections & Pavements using pavers Very low In the ‘very low’ category of workability where strict control is necessary, for example pavement quality concrete, measurement of workability by determination of compacting factor will be more appropriate than slump ( see IS 1199 ) and a value of compacting factor of 0.75 to 0.80 is suggested. Mass concrete, Lightly reinforced sections in slabs, beams, walls, columns, Floors; Hand placed pavements; Canal lining; Strip footings Low 25-75 Heavily reinforced sections in s...
Blog By Er. Navneet Kumar Sampling of Concrete Cubes for Test -As per IS 516-1959 Size of Test Specimens - Test specimen cubical in shape shall be 15 X 15 X 15 Cm. If the largest nominal size of the aggregate does not exceed 2 cm. 10 cm cubes may be used as an alternative. Cylindrical test specimens shall have a length equal to twice the diameter. They shall be 15 Cm in diameter and 30 cm long. Cube Moulds- The cube mould shall be of metal, preferably steel or cast iron, and stout enough to prevent distortion. The height of the mould and the distance between opposite faces shall be the specified size + 0·2 mm. The angle between adjacent internal face and between internal faces and top and bottom planes of the mould shall be 90° + 0.5°. The interior faces of the mould shall be plane surfaces with a permissible variation of 0·03 mm. The base plate shall be of such dimensions as to support the mould during the filling without le...
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