Method of Test for Restrained Expansion of Expansive Concrete using a Cylindrical Mold
By M. Tsujino, R. Yuasa and H. Hashida
Concrete Journal, Vol.52, No.6, Jun. 2014
- Synopsis
- A new test method to measure restrained expansive strain of expansive concrete for use as a concrete shrinkage cracking countermeasure has been developed. The present test method uses a cylindrical mold fitted with a strain gauge, along with a strain measuring device, to measure the restrained expansive strain of expansive concrete that was subjected to sealed curing. High correlation was observed in the results for restrained expansive strain in the cylindrical mold at the age of 7 days and strain produced with existing JIS A 6202 Annex 2 method A, with both methods yielding nearly identical values. Moreover, the newly developed method allows better evaluation of expansive strain through a compensation formula that takes into account the linear expansion coefficient of the concrete and strain gauge, even in an environment subject to temperature changes. Further, based on the expansion behavior, the strength characteristics, and other results of concrete combining a mineral admixture and expansive additive, the newly developed method was shown to be suitable for use for performance evaluation and quality control of increasingly sophisticated concretes.
- Keywords:
- expansive additive, expansive concrete, restrained expansion, crack, drying shrinkage, cylindrical mold
