Let's go through the steps as per **ACI 318** code for determining the **effective flange width** (\(b_f\)) for a T-beam. --- ## **Step 1: List Given Data** - **Beam web width (b_w):** 10 in. - **Slab thickness (h_f):** 5 in. - **Beam span (L):** 30 ft = 360 in. - **Distance to next beam (center-to-center):** 50 in. --- ## **Step 2: ACI 318 Effective Flange Width Criteria** According to **ACI 318-14 (Section 6.3.2.1)**, for T-beams, the effective flange width \(b_f\) **on each side of the web** shall not exceed: 1. **One-fourth the span length of the beam:** \( \frac{L}{4} = \frac{360}{4} = 90 \) in 2. **The web width plus 16 times the slab thickness:** \( b_w + 16h_f = 10 + 16 \times 5 = 10 + 80 = 90 \) in 3. **The center-to-center distance between beams:** \( 50 \) in --- ## **Step 3: Compute the Minimum** The **effective flange width** is the **smallest** of the above three values: - \( \frac{L}{4} = 90 \) in - \( b_w + 16h_f = 90 \) in - Center-to-center spacing = 50 in **The smallest is 50 in.** --- ## **Step 4: Final Answer** **The ACI-specified effective top flange width is:** \[ \boxed{50\ \text{in.}} \] **Answer:** **(B) 50 in.** --- ### **Summary Table** | Criteria | Value | |--------------------------------------------|-----------| | \( \frac{L}{4} \) | 90 in | | \( b_w + 16h_f \) | 90 in | | Center-to-center distance between beams | 50 in | | **Effective Flange Width (\(b_f\))** | **50 in** |