A prestressed rectangular beam 0.50m x 0.75m has a simple span of 10m and is loaded with a uniform load of 45 kN/m including its own weight. The prestressing tendon is 0.225 m from the bottom and produces an effective prestress of 1600 kN. Compute the fiber stress distribution in the concrete at midspan due to prestress eccentricity.

Concrete beam.

The cross section of a reinforced concrete beam is shown below .( 5 - No . 10 bars )are designed as the bottom bars and No. 3 stirrups as the vertical reinforcement . Considering a clear cover thickness = 1.5 in , sketch the layout of reinforcement and show bar spacings per AC1318-19 . Assume maximum aggregate size = 1 in and the minimum required effective depth of bottom bars = 20 inches .

PROBLEM TO SOLVE: 600 mm 400 mm 6-25mm diam. 90 mm Using fc' = 28 MPa, Mmax = +320 kNm Determine the following: a. Cracking Moment (kNm) b. Compressive Stress felt by concrete (MPa) c. Tension Stress felt by the tension bars (MPa) d. Moment of Inertia under critical condition e. Demand Capacity Ratio of Concrete under Compression Stress f. Compression force on concrete (kN) g. Distance of the compression concrete force from the neutral axis (mm)