Calculate the Modulus of elasticity of concrete
A pre-stressed concrete beam, having a cross-section of 150 mm width and 400 mm depth, is used over a span of 8 m. Straight tendons. which are having a stress of 1200 N/mm2, are provided with a constant eccentricity of 60 mm. The sectional area of tendons is 120 mm2. What shall be the percentage increase in stress in the wires when the beam supports a live load of 5 kN/m over whole of its span. The density of concrete is 24 kN/ m3. Modulus of elasticity of concrete and steel may be taken as 36 kN/m2 and 210 kN/m2 respectively.