Effects of chloride and chloride-free accelerators combined with typical admixtures on the early-age cracking risk of concrete repair slabs. (30th September 2015)

• Record Type: Journal Article
• Authors: Meagher, Thomas; Shanahan, Natallia; Buidens, Daniel; Riding, Kyle A.; Zayed, A.
• Is Part Of: Construction & building materials. Volume 94(2015)
• Page Start: 270
• Page End: 279
• Publication Date: 2015-09-30
• Subjects: Chemical admixtures -- Cracking risk -- Concrete pavement repair; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2015.07.003
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Ca(NO)3 based accelerator showed increased shrinkage, restraint stresses, and strength. Increase in temperature had a larger effect on setting time of CaCl2 based accelerator. Ca(NO)3 and CaCl2 based accelerators showed similar cracking tendencies at studied dosages. HIPERPAV modeling showed evening and nighttime placements to decrease cracking risk. Abstract: Accelerators are commonly added to concrete mixtures used for concrete repair slabs due to high early strength requirements. This study compared the effects of a calcium chloride-based accelerator and a calcium nitrate-based accelerator in rapid strength concrete mixtures on the early age cracking potential of concrete repair slabs. The results showed more shrinkage, higher restraint stresses, and higher strength for the calcium nitrate-based accelerator mixture. HIPERPAV simulated a lower cracking risk for the calcium nitrate-based accelerator mixture during evening and nighttime placements. Calorimetry, free shrinkage, and rigid cracking frame testing were used with the modeling software to observe trends in these mixtures.