Concrete Structure Damage: Causes, Defects and Common Lesions

External Agents

Physical: water, extreme temperatures, wind

Chemical: leaching, attack by carbon dioxide (CO2) dissolved in water (aggressive) and in air, sulfates, alkali aggregates, chlorides (de-icing salts), seawater

Reinforcement Damage

Manufacturing and storage: impurities, surface defects, surface corrosion

Hardening: oxidation and corrosion

Structural Defects

Design: conception, calculation, documentation

Execution and maintenance: concrete manufacturing and placement, reinforcement manufacturing and placement, maintenance

Lesions

Manifestations

• Cracks due to shrinkage
• Cracks due to movement restrained in the fresh state
• Structural cracks due to behavior
• Settlement cracks during concreting
• Cracks due to reinforcement slip or reduced stirrup spacing
• Cracks due to corrosion
• Frost damage
• Other damage in non-structural elements

Pillars

• Concrete crushing (rapid and very severe failure)
• Concrete disaggregation (very severe)
• Shear failure (rapid and very severe failure)
• Tensile failure (severe to very severe)
• Pillar buckling (rapid and very severe)
• Reinforcement corrosion (severity depends on the corrosion state)
• Corner failure (very severe)
• Stirrup detachment (very severe)
• Cracks due to bending (severe)
• Cracks due to hydraulic shrinkage (slight)
• Cracks due to plastic shrinkage at pillar head (slight if the concrete has adequate strength)
• Cracks in closure due to shortening of pillar head (severity depends on the error)
• Cracks due to deficient transmission of loads from pillar to foundation (severe)
• Corner failure at pillar head (slight)

Beams

• Cracks due to bending (severe)
• Cracks due to lateral bending (severe)
• Shear cracks (very severe)
• Cracks due to insufficient anchorage length (very severe)
• Cracks due to concrete crushing (very severe)
• Torsional cracks (severe)
• Cracks due to bending and shear (very severe)
• Cracks due to bending and torsion (very severe)
• Cracks due to abrupt change in reinforcement section (slight)
• Cracks due to lack of negative anchorage length (medium to severe)
• Cracks due to hydraulic shrinkage (medium)
• Corrosion cracks in the lower reinforcement of the beam (severe)
• Cracks due to restrained movement during hardening (slight)
• Cracks due to thermal shrinkage of the beam (medium)
• Cracks due to hydraulic shrinkage in the lower zone of deep beams (slight)
• Cracks due to poor reinforcement bond (medium to severe)
• Corner failure of beam (medium to severe)
• Cracks due to loose or insufficient negative reinforcement (severe)