Title: Designing for Effects of Creep and Shrinkage in High-Rise Concrete Buildings

Author(s): D.J. Carreira and T.D. Poulos

Publication: Symposium Paper

Volume: 246

Issue:

Appears on pages(s): 107-132

Keywords: age-adjusted modulus; column shortening; concrete; creep; creep superposition; differential shortening; elevation corrections; high-rise structures; modulus of elasticity; shrinkage

DOI: 10.14359/18982

Date: 9/1/2007

Abstract:
Differential shortening caused by creep and shrinkage of reinforced concrete columns and shear walls affects the serviceability of high-rise buildings. For structures up to 30 stories or 400 ft (120 m) high, the effects of creep and shrinkage are usually ignored without serious consequences. For reinforced concrete buildings beyond 30 stories, and for shorter buildings of hybrid or mixed construction, ignoring the effects of creep and shrinkage may create several undesirable conditions in the serviceability of the structure. Owners of high-rise concrete buildings are aware of the potential for undesirable behaviors in service in both structural and in nonstructural elements from the effects of differential shortening of columns and shear walls. Examples include sloping floors; cracking of structural members and interior partitions; buckled elevator guide rails, misaligned elevator stops relative to floors, and damage to façade elements and plumbing risers. To minimize these behaviors, the structural engineer is challenged to predict, design for, and adjust for differential shortening in each of the structural components during construction, as well as forecast future behaviors. The structural design process and related construction requirements are discussed and illustrated within.