What is Confined Masonry? Design, Construction & Benefits

Introduction to Confined Masonry

Confined masonry construction is a structural system in which masonry walls are confined with reinforced concrete (RC) tie columns and tie beams. This system is widely used in earthquake-prone regions because it provides better strength and ductility than unreinforced masonry.

In Pakistan, confined masonry is becoming popular for 5 Marla, 10 Marla, and residential houses due to its safety and cost effectiveness.

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What is Confined Masonry?

In confined masonry:

• Masonry walls are constructed first
• Then RC tie columns and bands are cast around the walls
• Walls act as load-bearing structural elements

⚠️ This system is different from RCC frame structure, where columns and beams are constructed first.

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Main Components of Confined Masonry

🔹 Masonry Walls

• Burnt clay bricks or concrete blocks
• Cement sand mortar (1:4 or 1:5)

🔹 Tie Columns (Vertical)

• Provided at:
  • Wall corners
  • Wall intersections
  • Openings (doors/windows)

Typical size: 9″ × 9″ or 9″ × 12″

🔹 Tie Beams / Bands (Horizontal)

• Plinth band
• Lintel band
• Roof band

These bands improve earthquake resistance.

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Construction Procedure (Step by Step)

Step 1: Foundation

• Strip or raft foundation depending on soil
• Starter bars for tie columns provided

Step 2: Masonry Wall Construction

• Walls built up to lintel level
• Openings left for doors & windows

Step 3: Tie Columns Casting

• Formwork fixed around walls
• Reinforcement placed
• Concrete poured

Step 4: Tie Beams / Bands

• RC bands cast at plinth, lintel & roof level

Step 5: Roof Slab

• RCC slab cast normally

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Confined Masonry vs RCC Frame Structure

Feature	Confined Masonry	RCC Frame
Cost	Lower	Higher
Earthquake Resistance	High	High
Construction Speed	Faster	Slower
Skill Requirement	Medium	High
Suitable for	Low-rise houses	Multi-storey buildings

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Advantages of Confined Masonry

✔ Better earthquake performance
✔ Economical for residential houses
✔ Simple construction technique
✔ Less steel consumption
✔ Ideal for 1–3 storey buildings

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Disadvantages

❌ Not suitable for high-rise buildings
❌ Proper detailing is essential
❌ Poor workmanship can reduce strength

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Confined Masonry in Pakistan (Practical Use)

In Pakistan (especially KPK, AJK, Northern areas):

• Recommended for seismic zones
• Suitable for 5 Marla & 10 Marla houses
• Can reduce construction cost by 10–15% compared to RCC frame

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Common Mistakes to Avoid

⚠ Missing tie columns at wall junctions
⚠ Weak mortar ratio
⚠ Improper anchorage of bands
⚠ Delayed casting of tie columns

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Conclusion

Confined masonry is a safe, economical, and earthquake-resistant construction system. If designed and executed properly, it is an excellent option for residential buildings in Pakistan.