Title: Factors lnfluencing Thermal Stresses in HPC Members

Author(s): Arshad A. K t nan William D. Cook and Denis Mitchell

Publication: Symposium Paper

Volume: 172

Issue:

Appears on pages(s): 135-154

Keywords: High-performance concretes; high-strength concretes; mechanical properties; thermal properties

DOI: 10.14359/6130

Date: 12/1/1999

Abstract:
An extensive experimental study was conducted to investigate the concrete properties needed to predict the development of temperatures and resulting restraint stresses in concrete members during hydration. This paper addresses the key mechanical properties including compressive’ stress-strain response, elastic modulus, tensile strength, shrinkage and creep of high performance concrete during hydration. These properties were measured under temperature-matched, sealed and air-dried curing, and results were compared with those of normal-strength concrete. A relationship is proposed to predict the compressive strength development of hydrating concrete in terms of equivalent age. It was also observed that predictions using the 1990 CEB-FIP code creep expressions agreed reasonably well with the measured creep strains of the normal and medium-strength concretes. The high-strength concrete, loaded at very early ages (less than 24 hours), exhibited considerably large creep values. Effect of different curing conditions, early-form stripping and concrete strength on the temperature and stress development in different sizes and shapes of concrete elements is also presented.