Question

A pretressed concrete beam 200mm wide and 300 mm deep , is pretressed with wire (area = 320 mm² ) located at a constant eccentricity of 50 mm and carrying an initial stress of 1000 N/ mm² . The span of the beam is 10m . calculate the percentage loss of stress in wires if (a) the beam is pre_ tensioned and (b) the beam is post_tensioned , using the following data: Es = 210 kN/mm² and Ec = 35 kN/ mm² relaxation of stress in steel = 5 percent of initial stress; shrinkage of concerete=300×10-6 for pre tensioning and 200× 10-power6 for post tensioning ; creep cofficient= 1.6 slip at Anchorage = 1mm ; fractional cofficient for wave effect = 0.0015 per m.
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Answer 1

Answer:

sorry but I can't........