Title: Shrinkage and Crack Propagation of Flowing Concrete at Early Ages

Author(s): S. Hiraishi, K. Yokoyama and Y. Kasai

Publication: Symposium Paper

Volume: 179

Issue:

Appears on pages(s): 671-690

Keywords: admixtures; cracking (fracturing) concrete; shrinkage; surface drying

DOI: 10.14359/6067

Date: 6/1/1998

Abstract:
Flowing concrete is a highly flowable and segregation resistant concrete. Shrinkage of the concrete at early ages up to 24 hours under a constant air flow of 8 m/s starting at the age of 2 hours, and crack propagation of the concrete in a restricted form with a thickness of 50 mm have been studied. The experiments were done by controlling the following four mixture parameters, (I) Water - cement ratio: 0.60, 0.45, 0.35, 0.30 and 0.27, (2) Unit amount of water: 185, 175 and 170 kg/m3, (3) Type of cement: normal, high early strength and belite portland cement, (4) Type of inorganic admixture: a ground granulated blast furnace slag and a fly ash and their respective mixture proportions. Effects of the above parameters on crack propagation at early ages were investigated on the basis of authors’ crack evaluation criteria.