Problem: A $25\ \text{mm}$ uncoated bottom bar has $f_y=420\ \text{MPa}$ and is embedded in normal-weight concrete with $f'_c=28\ \text{MPa}$. Clear cover is $75\ \text{mm}$, clear spacing to the adjacent developed bar is $100\ \text{mm}$, and $K_{tr}=0$. Determine the required straight tension development length.

Problem: Four $25\ \text{mm}$ epoxy-coated bottom bars are developed in normal-weight concrete with $f_y=420\ \text{MPa}$ and $f'_c=21\ \text{MPa}$. For the bar being checked, $c_b=40\ \text{mm}$. Two $10\ \text{mm}$ transverse-reinforcement legs cross the potential splitting plane within each $s=200\ \text{mm}$ spacing. There are $n=4$ developed bars along that splitting plane. The coating condition requires $\psi_e=1.5$. Determine $K_{tr}$ and $l_d$.

Problem: A $20\ \text{mm}$ top bar has more than $300\ \text{mm}$ of fresh concrete cast below it. It is epoxy coated under a condition that gives $\psi_e=1.5$. Use $f_y=420\ \text{MPa}$, $f'_c=28\ \text{MPa}$, normal-weight concrete, and a confinement ratio capped at $2.5$. Determine $l_d$.

Problem: A $25\ \text{mm}$ bottom, uncoated bar in normal-weight concrete has $f_y=420\ \text{MPa}$ and $f'_c=28\ \text{MPa}$. Its clear spacing and cover satisfy the favorable simplified-table conditions. Determine the simplified development length.

Problem: Determine the compression development length of a $25\ \text{mm}$ deformed bar with $f_y=420\ \text{MPa}$ in normal-weight concrete with $f'_c=28\ \text{MPa}$. No qualifying confinement reduction is taken.

Problem: A $20\ \text{mm}$ uncoated bar in normal-weight concrete has $f_y=420\ \text{MPa}$ and $f'_c=28\ \text{MPa}$. It terminates in a standard $90^\circ$ hook. The applicable cover conditions permit $\psi_c=0.7$, but no hook-confinement reduction is taken, so $\psi_r=1.0$. Determine $l_{dh}$.

Problem: A $25\ \text{mm}$ footing dowel carries compression. From Example 5, $l_{dc}=476.2\ \text{mm}$, but the detail provides only $375\ \text{mm}$ of straight embedment before the bar bends into a $90^\circ$ hook. Is the dowel adequately developed in compression?

Problem: A permitted tension lap splice has a development length $l_d=800\ \text{mm}$. The provided reinforcement is less than twice that required by analysis and all bars are spliced at the same location. Determine the required splice length.

Problem: Two $20\ \text{mm}$ bars with $f_y=420\ \text{MPa}$ are lap-spliced in compression. Use the basic NSCP expression for bars not requiring a higher-strength-steel provision and assume no special low-strength-concrete or confinement modifier. Determine $l_{sc}$.

Problem: A straight $25\ \text{mm}$ bar has an individual required development length of $722\ \text{mm}$ before the bundled-bar modifier. Determine the required length when that bar is part of (a) a three-bar bundle and (b) a four-bar bundle.

Problem: A $3.0\ \text{m}$ square footing supports a $400\ \text{mm}$ square column. Bottom $20\ \text{mm}$ bars have $75\ \text{mm}$ edge cover and a calculated tension development length of $462\ \text{mm}$. Check straight anchorage from the column face to the bar end.

Problem: A normal-weight concrete member uses a headed $25\ \text{mm}$ Grade 420 bar with $f'_c=28\ \text{MPa}$, no epoxy coating, $50\ \text{mm}$ clear cover, $100\ \text{mm}$ clear spacing, and net head bearing area at least $4A_b$. Check the ACI 318M-14 teaching eligibility represented by this topic and calculate $l_{dt}$.

Problem: A beam calculation shows that a selected pair of bars is no longer required for flexure at a theoretical point $1.20\ \text{m}$ from the support. Let $d=500\ \text{mm}$, $d_b=25\ \text{mm}$, the required straight development from the governing critical section be $650\ \text{mm}$, the available development be $850\ \text{mm}$, and the bars physically terminate $600\ \text{mm}$ beyond the theoretical cutoff. Screen the cutoff detail.

Problem: A large bar cannot be lap-spliced under the applicable provision and the construction joint leaves insufficient length for an ordinary lap. Should the designer invent an equivalent lap multiplier for a coupler or field weld?