## PERMISSIBLE STRESSES (CLAUSE B-2, IS456:2000)

PERMISSIBLE STRESSES (CLAUSE B-2, IS456:2000),Permissible Stresses in Concrete ( IS 456),Permissible Stress in Steel Reinforcement ( IS 456) PERMISSIBLE STRESSES (CLAUSE B-2, IS456:2000) The working stress method is based upon the concept of permissible stresses. Permissible stresses are obtained by dividing the ultimate strength of concrete or yield strength of steel (0.2% proof stress) by appropriate factors of safety. The factors of safety used in working stress method are: (i) For concrete (a) in bending compression - 3.0 (b) in direct compression - 4.0 (ii) For steel - 1.78 There are greater chances of variation of strength of concrete due to improper compaction, inadequate curing and variation in the properties of concrete. The chances of variation in the properties of steel are less as it is fabricated in factories where good workmanship and better quality control is possible. So, lesser value of factor of safety is used for steel as…