Given fc' = 35 MPa, solve for the modulus of elasticity of concrete a. 27,800.00 MPa b. 27,805.57 MPa c. 200,000.00 MPa d. None of the above If fc'= 42 MPa, solve for B. a. 0.65 b. 0.75 C. 0.85

A concrete masonry unit has actual gross dimensions of 7@5/8′′ * 7@5/8′′ *7@5/8′′. The unit is tested in a compression machine with the following results:Maximum failure load = 83 kipsNet volume = 312.7 in.3a. Is the unit categorized as solid or hollow? Why?b. Calculate the gross area compressive strength.c. Calculate the net area compressive strength.

2- A steel food is stretches between two rigid walls and carries a tensile load f 6000 N at doc. If the allowable stress is not to exceed 130 MPa at -24°C, what is the minimum diameter of the rod ? Assume + = 11.7 (106) M/C and E= 200 GPa. ST + 7 P=6000 8 Figure: P&CON L

0 ww C. 6.31 A concrete mix includes the following ingredients per cubic foot: a. Cement = 25 lb b. Water = 11 lb c. No admixture Table P6.31 shows possible changes that can be made to the mix ingredi- ents. Indicate in the appropriate boxes in the table what will happen in each case for the workability and the ultimate compressive strength as increase, decrease, or approximately the same. TABLE P6.31 to dignope Cement (lb) 25 28 25 25 25 25 25 amigur Water (lb) 15 11 11 8 11 11 11 Admixture None None Water reducer Water reducer Superplasticizer Air entrainer Accelerator What Will Happen? www.10345 Ultimate Compressive we Strength Workability