Title:
Prediction of Concrete Drying Shrinkage From Short-Term Measurements
Author(s):
Jamal A. Almudaiheem and Will Hansen
Publication:
Materials Journal
Volume:
86
Issue:
4
Appears on pages(s):
401-408
Keywords:
concretes; drying shrinkage; errors; measurement; regression analysis; shrinkage; specimens; volume change; Materials Research
DOI:
10.14359/2178
Date:
7/1/1989
Abstract:
Data from literature on drying shrinkage at different relative humidities of concretes of different sizes and shapes were used to evaluate shrinkage equations proposed by ACI 209, Almudaiheem and Hansen (AH), and Bazant and Panula (BP). The AH and BP equations fit the data well, regardless of specimen size and shape, when optimized to each data set. However, the ACI 209 equation does not satisfactorily predict the influence of specimen size and shape on shrinkage. It is therefore not suitable for shrinkage prediction of structural size members from results on smaller laboratory-sized specimens. When using the AH equation, which is a modified ACI 209 equation, and a single shrinkage measurement at 30 days or later of a laboratory specimen (100 mm in diameter) of the concrete in question, the prediction errors are within ñ 35 percent of the true shrinkage value at any time later than 30 days of drying. This procedure is a significant improvement over the current ACI procedure and eliminates the large uncertainty in shrinkage prediction due to material parameters. The remaining shrinkage error is mainly due to the size effect on shrinkage prediction.