Section 12.2 Development of Deformed Bars in Tension

Section 12.2.2 is used to calculate the development length ℓ_d. The calculated ld never taken as less than 300 mm in accordance with 12.2.1 and f'_c is limited to 8Mpa in accordance with 12.1.2. For sections with multiple concrete strengths, the minimum concrete strength is used to determine the limiting stress.

The ld of deformed bars in tension calculated based on equation 12-1:

ℓ d = 1.15 \frac{k_{1} k_{2} k_{3} k_{4} f_{y}}{(d_{c s} {+ k}_{t r}) \sqrt{f_{c}^{'}}}

The value (d_cs + k_tr) limited to 2.5 d_b, and K_tr is conservatively assumed to be zero.