Prediction of Drying Shrinkage Cracking of Eco-efficient Steel Chip Reinforced Cementitious Composite Considering Tensile Creep

Abstract

This paper reports on the characteristics of drying shrinkage and creep of steel chip reinforced cementitious composite (SCRCC). In this study, first, four restrained wall specimens made of normal mortar and SCRCC with various numbers of steel reinforcing bars (4 or 10) were prepared to compare drying shrinkage characteristics. The specimens were re-strained on the rigid laboratory floor so that shrinkage cracks were induced. The drying shrinkage strains were measured by the contact gauge method and compared with unrestrained small specimens. The number of cracks was simultane-ously observed. Second, bond tests were prepared to evaluate the bond characteristics between the SCRCC and the steel bar. Third, creep tests were performed to improve the accuracy of the analysis of the drying shrinkage behavior. Twelve block specimens were made and a constant flexural load was applied for 7, 14, and 28 days. The observed shrinkage strains and creep strains of SCRCC were modeled according to CEB-FIP Model Code 1990. These models were incor-porated with bond computation between the SCRCC and the steel bar to predict the number of drying shrinkage cracks. The computed equivalent number of cracks based on the shrinkage strain model, the creep model, and the bond model derived from a pull-out test generally agreed with the test results.