Maximum strain in concrete taken for design is 0.0040 while strain in deformed bar is calculated with an offset at 0.0015. A beam has an effective depth of 550 mm and is reinforced with Fe415 steel. What would be the value of limiting neutral axis depth (in mm) for this beam?

A simply supported post-tension beam as shown in Figure (1), span length is 14m, carries a uniformly distributed service live load of 10 kN/m. Find the value and location of initial pre-stress force (Pi), so that the mid span stresses in concrete at top fiber is zero at initial stage and zero stress at bottom fiber in service stage. Total losses in pre-stressed force are 15%. 100 200 100 750 100 400 Typical Cross section. Figure (1)