Title:
Effects of Atmospheric and Construction Conditions on Concrete Equivalent Ages
Author(s):
Gary S. Wojcik
Publication:
Materials Journal
Volume:
101
Issue:
5
Appears on pages(s):
376-384
Keywords:
bridge deck; concrete; curing; fly ash; silica fume
DOI:
10.14359/13423
Date:
9/1/2004
Abstract:
Concrete maturity, often indicated by its equivalent age, is determined by the interaction of the temperature-dependent exothermic hydration reactions and the atmospheric conditions and curing regimen experienced during early ages. While indexes of concrete maturity have gained wide acceptance in determining proper opening times of structures and in investigations of structural failures, there is a need for a study showing how the maturity in a given structure may change depending on the environmental conditions experienced. In this paper, the SUNY Local Atmosphere Bridge Simulation (SLABS) model is used to predict the equivalent ages of New York State Department of Transportation’s Class HP concrete bridge decks for a variety of atmospheric and construction conditions. After 24 h of hydration, the equivalent ages of the same bridge deck vary from 10 h to more than 60 h depending on conditions when averaged over the deck thickness. They also can vary by more than 20 h through the slab thickness. In cases of self-desiccation, the maturity method may provide misleading results.