---
title: "Beam-column joint with ductile details"
subject: "Design of RCC Structure"
chapter: 12
key: "semester_7/design_of_rcc_structure:beam-column-joint-with-ductile-details"
source: https://www.bctengineer.com/q/semester_7/design_of_rcc_structure/beam-column-joint-with-ductile-details
site: BCT Engineering
---

# Beam-column joint with ductile details

Design of RCC Structure · Chapter 12: Introduction to Earthquake Resistant Design and Provisions for Ductile Detailing

- Asked in: 2081 Bhadra, 4 marks
- Video: [Important Notes on Beam Column Joint || Joint Detailing](https://www.youtube.com/watch?v=qLJPQoeri_g) — Civil Engineering
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/design_of_rcc_structure/beam-column-joint-with-ductile-details
- Whole chapter: https://www.bctengineer.com/md/semester_7/design_of_rcc_structure/chapter-12

## Question

Draw a neat sketch of beam-column joint including ductile details.

## Short answer

At an exterior joint, column confining hoops continue through the joint at 75-100 mm spacing, and beam bars anchor into the far face with Ld from the inner face plus a 90-degree bend of 10 phi. Beam stirrups start 50 mm from the face at min(d/4,8phi,100 mm) over 2d; no lap splices in the joint.

## Answer

```text
          Column above (hoops s=75-100)
                  | | | |
           +------#########------+
 top bars  =====>#  joint  #<====  top bars
 anchored  |     #  hoops   #     |  continuous
 Ld from   |     #  s<=100  #     |
 inner face|=====>#         #<====|
 + 90 bend +------#########------+
 (10 phi)         | | | |
          Column below (hoops s=75-100)

  Beam: hoops 50 mm from face, s <= d/4, 8phi, 100
```
Ductile details shown:
- Column confining hoops (closed, $135^\circ$ hooks, $6\phi$ tail) run continuously through the joint at $\le 100$ mm (up to 150 mm if beams frame in on all four faces).
- Beam longitudinal bars at an exterior joint extend to the far face of the column, are anchored for $L_d$ measured from the inside face, and end in a $90^\circ$ bend with a standing leg of $\ge 10\phi$ turned into the joint (top bars bent down, bottom bars bent up).
- Column bars are continuous through the joint; no lap splice is made within the joint (column laps go in the central half of the column height).
- Beam stirrups start 50 mm from the joint face, with spacing $\le \min(d/4,\ 8\phi,\ 100\text{ mm})$ over $2d$; no beam lap splice within $2d$ of the joint face.
- Strong-column weak-beam proportioning, so that hinges form in the beams and the joint and columns remain essentially elastic.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is the column hoop spacing through the joint?
   A. 300 mm
   B. At most 100 mm (up to 150 mm if beams frame on all four faces)
   C. Hoops are omitted
   D. d/2
   Answer: B. Confining hoops continue through the joint at <= 100 mm, relaxed to 150 mm when beams frame on all four sides. (Key point: Joint hoop spacing)

2. Where must lap splices of column bars NOT be made?
   A. In the middle half of the column
   B. Within the joint or within 2d of its face
   C. Between floors
   D. At the base
   Answer: B. Splices there would be in hinge/high stress zones, so they are prohibited. (Key point: Lap splices at joints)

3. How do beam stirrups begin near the joint face?
   A. First stirrup at 50 mm from the face, spacing <= min(d/4, 8 phi, 100 mm) over 2d
   B. First at 300 mm, spacing d/2
   C. No stirrups within 2d
   D. At 150 mm uniform
   Answer: A. Close stirrups over 2d confine the possible hinge region. (Key point: Beam stirrups near joint)

## Close variants set in other exams

- [Define ductility, joint detailing sketch](https://www.bctengineer.com/question.md?key=semester_7%2Fdesign_of_rcc_structure%3Adefine-ductility-joint-detailing-sketch) — Design of RCC Structure, chapter 12, asked 2×

## Related in Design of RCC Structure

- [Ductile design per IS 13920, beam and column](https://www.bctengineer.com/question.md?key=semester_7%2Fdesign_of_rcc_structure%3Aductile-design-per-is-13920-beam) — Design of RCC Structure, chapter 12
- [Column 350x350, 1440 kN, ductile detailing](https://www.bctengineer.com/question.md?key=semester_7%2Fdesign_of_rcc_structure%3Acolumn-350x350-1440-kn-ductile-detailing) — Design of RCC Structure, chapter 10, asked 2×
- [Short column 300x450 with ductile detailing](https://www.bctengineer.com/question.md?key=semester_7%2Fdesign_of_rcc_structure%3Ashort-column-300x450-with-ductile-detailing) — Design of RCC Structure, chapter 10
- [Ductility requirement for beam, column, joints](https://www.bctengineer.com/question.md?key=semester_7%2Fdesign_of_rcc_structure%3Aductility-requirement-for-beam-column-joints) — Design of RCC Structure, chapter 12
- [Ductile detailing of beams and columns](https://www.bctengineer.com/question.md?key=semester_7%2Fdesign_of_rcc_structure%3Aductile-detailing-of-beams-and-columns) — Design of RCC Structure, chapter 12, asked 2×
- [Ductile detailing of columns, confining steel](https://www.bctengineer.com/question.md?key=semester_7%2Fdesign_of_rcc_structure%3Aductile-detailing-of-columns-confining-steel) — Design of RCC Structure, chapter 12, asked 4×

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