Control of Shrinkage Cracking by Reinforcement
By J. Kodera
Concrete Journal, Vol.44, No.8, Aug. 2006
- Synopsis
- Based on the investigation of shrinkage cracking induced in a single track box type tunnel, sidewalls of underground railway stations, and cantilever slabs of continuous reinforced concrete viaducts, the crack controlling effect of reinforcement was studied, and the minimum amount of reinforcement to avoid wide cracks was proposed. According to this study, the relationship between the amount of the wide cracks and the effective steel ratio Pef=As/Acef is very close. The effective area of concrete Acef was calculated following Euro code No.2. The minimum amount of reinforcement was proposed as follows. For sidewalls near the construction joint between bottom slabs Pef=0.6% or as=12cm2/m, and for the cantilever slabs P=0.8%.
- Keywords:
- shrinkage cracking, thermal contraction, effective steel ratio, crack control
