Cracking of Beams and Walls Subject to Restrained Deformations at SLS

• Published in: Control of Cracking in Reinforced Concrete Structures pp. 1 - 2
• Main Authors: Chauvel, Daniele, Barre, Francis, Cortade, Jacques, Dubois, Jean-Philippe, Erlicher, Silvano, Gallitre, Etienne, Coste, Jean-François, Bisch, Philippe, Mazars, Jacky, Labbé, Pierre
• Format: Book Chapter
• Language: English
• Published: United States John Wiley & Sons 2016; John Wiley & Sons, Incorporated; John Wiley & Sons, Inc
• Subjects: Civil Engineering & Construction Materials; Concrete & Related Materials; concrete cooling time; cyclic thermal shock; surface cracking; tensile strength; thermal insulation; transient thermal gradient
• ISBN: 9781786300522; 1786300524
• DOI: 10.1002/9781119347088.ch8

Cracking on the concrete surface can normally be avoided by adopting a number of precautions, including the thermal insulation characteristics of formworks and by an adequate curing period. There is a risk of cracks occurring up to several days' duration post concreting, dependent on the concrete cooling time. This duration should be considered at an early age of concrete, as it depends on the size of the concrete element concerned. In order to control or limit crack width, in addition to crack distribution, the potential widths should first be calculated. When cracking occurs, the stress in the concrete is equal to its tensile strength. The preliminary step of transient thermal gradient is to assume that this method resulting from thermal shock can be acceptably modelled using an equivalent bilinear curve. Two thermal shock cases may be assessed which includes daily cyclic thermal shock and thermal shock with a constant temperature maintained over time.