Title: Effect of Non-Ground-Granulated Blast-Furnace Slag as Fine Aggregate on Shrinkage Cracking of Mortars

Author(s): Ilker Bekir Topcu and Turhan Bilir

Publication: Materials Journal

Volume: 107

Issue: 6

Appears on pages(s): 545-553

Keywords: concrete; cracking; fine aggregate; ground-granulated blast- furnace slag; mortar; ring test; shrinkage

DOI: 10.14359/51664040

Date: 11/1/2010

Abstract:
In this study, the effect of non-ground-granulated blast-furnace slag (n-GGBS) as fine aggregate in mortars on shrinkage cracking was investigated. The n-GGBS replaced fine aggregate by weight. The replacement ratios ranged from 0 to 100% in increments of 10%. Unit weight, ultrasonic pulse velocity, flexural strength, compressive strength, and length change due to free shrinkage were determined by producing prismatic mortar specimens for each series. The moduli of elasticity were also determined by producing cubic mortar specimens. The ring test was conducted to determine the effect of n-GGBS on shrinkage cracking. The length and width of the cracks that occurred during the ring test were measured using an optical microscope and a caliper. Consequently, it was observed that the increase in n-GGBS content decreased shrinkage cracking because of the porous structure of mortar specimens related to the structure of n-GGBS. Furthermore, the flexural strength, compressive strength, and modulus of elasticity also decreased for the same reason.