Problem 3)

Gr. 60 steel

4500 psi concrete

cover?

inside radius = ?

12"

stirrup size?

S

CE 402-

Homework Assignment #3

3 #11 bars

cover = ?

24" 27"

(a) Determine the provided (P), minimum (Pain), balanced (P), and maximum (P) steel ratios

(for tension controlled, i.e. ,-0.005 or -0.9).

(b) Calculate the nominal moment capacity, Ma

3"

(c) Calculate the strain in steel (,) when concrete reaches its ultimate strain (6,-0.003) and

determine if the reduction factor () is equal to 0.9 [refer to figure 3.5, page 73]

(d) Calculate the design moment capacity, M.

(e) Select the smallest bar size for the stirrup and calculate the inside radius.

(f) If the concrete beam is not exposed to weather and ground contact, what is the minimum cover?

Check if the bottom cover provided is adequate.

Name:

Due Date

(g) Determine the minimum spacing for the primary reinforcing bars. Using the inside radius and

minimum cover determined from part (e) and (f), calculate the available spacing, S. State clearly

whether the spacing is enough?