Comparative study between strain gages for determination of autogenous shrinkage

ABSTRACT The Carlson-type strain gages are the most suitable for the measurement of autogenous shrinkage. However, your high cost is usually a limiting factor for your employment. A more economical alternative would be the use of Self-Temperature-Compensation Gages to be embedded in concrete. The main objective of this work was to verify if Self-Temperature-Compensation Gages can be used instead of the Carlson type to determine the autogenous shrinkage in high performance concrete. It was carried out measurements of the autogenous shrinkage, for the same concrete mix, using the two types of extensometers. The difference in the means of the autogenous shrinkage results between these two types of extensometers was typically less than 10x10-6 m/m.

摘要 卡尔森型应变计（Carlson-type strain gages）是最适用于自收缩（autogenous shrinkage）测量的装置。但其高昂的成本通常限制了其推广应用。更为经济的替代方案为采用埋置于混凝土中的自温度补偿应变计（Self-Temperature-Compensation Gages）。本研究的核心目标为验证自温度补偿应变计能否替代卡尔森型应变计，以测定高性能混凝土（high performance concrete）的自收缩性能。研究针对同一配合比的混凝土，分别采用两种引伸计（extensometers）开展了自收缩测试。两种引伸计的自收缩结果均值之差通常小于10×10^-6 m/m。