The previous article mentioned the analysis, judgment, and treatment of cracks in concrete structures - column section, which is very popular. Today, we will continue to bring you an article on the analysis and treatment of structural cracks in concrete beams.

This article takes the location and morphology of cracks in concrete structures as clues, lists the causes, properties, and impact on structures of 14 common cracks, and provides targeted treatment suggestions.

Analysis, Judgment, And Treatment Of Structural Cracks In Concrete Beams(1)

8.

Cross edge upper area

Vertical cracks from top to bottom, not penetrating

Reasons for crack formation?

Negative bending moment tension

Dismantling the mold too early

Insufficient concrete strength

Insufficient reinforcement

Reinforcement displacement

Accidental overload

Cracks?

Stress cracks

Construction cracks

Impact of cracks?

When the width is large insecurity

Affects visibility

It basically does not affect the bearing capacity

Affects durability

Crack treatment?

Covering cracks

Reinforcement if necessary

9.

Cross edge upper and lower areas on both sides

Vertical cracks in the upper and lower areas, not penetrating

Reasons for crack formation?

Settlement difference

Relative displacement causes restrained bending moment to crack in tension

Crack?

Forced displacement causes stress cracks

Construction cracks

The impact of cracks?

Insecurity when the width is large

Affects visibility

May affect load-bearing capacity

Affects durability

Crack treatment?

Covering cracks

Reinforcement if necessary

10.

Beam side waist area

Equal spacing vertical cracks, wide in the middle and narrow at both ends

Reasons for crack formation?

Insufficient reinforcement in construction

Insufficient maintenance

Dry shrinkage cracks

Crack?

Construction and maintenance defects

Residual cracks

The impact of cracks?

Insecurity when the width is large

Affects visibility

Not affecting load-bearing capacity

Affects durability

Crack treatment?

Masking cracks after stable development

11.

At the junction of main and secondary beams

Octagonal cracks in the lower area of the secondary beam under concentrated load

Reasons for crack formation?

Small cross-section of the main beam

Insufficient concrete strength

Insufficient local reinforcement leads to tensile cracking of concrete

Crack?

Stress induced tensile cracks caused by design and construction defects

The impact of cracks?

Insecurity

Affects visibility

Has an impact on local bearing capacity and durability

Crack treatment?

Covering cracks

Reinforcement treatment is required

12.

Reinforcement overlap connection area

Local transverse cracking at both ends of the overlapped steel bars

Reasons for crack formation?

Joint at high bending moment

Large percentage of joint area

Insufficient overlap length

Insufficient coupling

Insufficient protective layer

Crack?

Construction structure cracks

The impact of cracks?

Insecurity

Affects visibility

When the crack is large, it may affect the local bearing capacity

Affects durability

Crack treatment?

Covering cracks

Reinforcement treatment if necessary

13.

The concave corner area below the folded beam

Cracking in local areas caused by concave corners and corners

Reasons for crack formation?

Insufficient anchoring of steel bars on both sides

Local stress concentration

Insufficient concrete strength

Crack?

Construction structure cracks

The impact of cracks?

Insecurity

Affects visibility

Greater width may have an impact on local bearing capacity

Affects durability

Crack treatment?

Covering cracks

Reinforcement treatment if necessary

14.

Variable cross-section beam concave corner area

Cracking through section along concave angle

Reasons for crack formation?

Tensile cracking caused by temperature and shrinkage

Insufficient reinforcement in construction

Crack?

Construction and maintenance cracks

Temperature shrinkage cracks

The impact of cracks?

Insecurity

Affects visibility

It basically does not affect the bearing capacity

Affects durability

Crack treatment?

Timely sealing of cracks

Reinforcement treatment if necessary