What is the modulus of rupture where the sand-lightweight concrete has an f of 4000 psi? (The result must be written in an integer.) Answer:

A concrete test cylinder with a cross-sectional area of 28.3 in squared is to be tested in axial compression. Before loading two marks are scribed on the cylinder precisely 8 in apart (as shown in the figure below) when the load is 40,000 lb the marks are measured and found to be 7.997 in apart determine the E value for this concrete. Assume an approximately linear relationship between stress and strain.

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)