(Use your own words !!!, similarities will be 2.5. The stress-strain diagram of a concrete specimen under compressive loads is usually represented by a parabola up to the ultimate strength with the following formula. 28 -[2-(A)] , and e, is the stress and strain of concrete, f, is the ultimate strength of concrete and E is the strain at ultimate strength. If the compressive strength is 35 MPa and strain corresponding to 0.002 at this ultimate strength; a) Schematically plot the above stress-strain diagram up to ultimate strength and show , &, J. and on the plot. b) Determine the initial modulus of elasticity (E.) of this material. c) Determine the tangent modulus of elasticity (E) at 70% of the ultimate load. d) Determine the secant modulus of elasticity (E,) at 40% of the ultimate load. e) Sort the three modulus of elasticity in decreasing order.