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Structural vs non-structural cracks and causes

Short answer

Structural cracks are wide (>1 mm), growing, and caused by overloading, settlement, design faults, or corrosion, threatening stability. Non-structural cracks are narrow, hairline, stable, caused by shrinkage, temperature changes, or poor curing, mainly affecting appearance.

Differentiate between structural and non-structural cracks and with the help of neat sketches. Write down its causes of occurrence.

PointStructural cracksNon-structural cracks
MeaningCracks due to faults affecting strength and stabilityCracks due to internal stresses in materials
WidthWide (often > 1 mm), growingNarrow, hairline, stable
CausesOverloading, settlement, design faults, earthquake, corrosionShrinkage, temperature, moisture, poor curing
PatternDiagonal, step, vertical through thicknessRandom, map type, horizontal in plaster
DangerCan cause collapseMostly appearance, durability
RepairEpoxy injection, jacketing, underpinningCement slurry, filling, new plaster
 Structural (settlement)     Non-structural (shrinkage)
  _______________              _______________
 |  \  step crack |           | ~~ map cracks  |
 |   \_           |           |  ~~            |
 |     \_  wide   |           |                |
 |_______\________|           |________________|
   foundation settles

Causes

Structural: overloading, unequal settlement of foundations, poor design and detailing, shear and bending failure, corrosion of steel, earthquake and wind, early removal of formwork. Non-structural: drying shrinkage of mortar, plaster and concrete, thermal expansion and contraction, moisture movement of bricks, chemical action (sulphate attack), vegetation, poor materials and workmanship.

✓ Answer checked by Claude Opus 5.5 (high effort)

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