Arosha Dabarera, Warangkana Saengsoy, Krittiya Kaewmanee, Takeshi Nakazaki, Thanapatch Lerdsupavaree and Somnuk Tangtermsirikul

DOI: 10.14456/sjst-psu.2019.149

pp. 1184 - 1191

Abstract

Fly ash and slag are two SCM’s utilized widely as partial replacements of cement in mass concrete. Different chemical,
physical properties and reaction behavior cause fly ash-cement blend to differ from slag-cement blend in terms of thermal
properties and thermal cracking in mass concrete. In this study, the time-dependent behavior of specific heat, thermal
conductivity, and coefficient of thermal expansion (CTE) of hardening cement pastes containing fly ash and slag are
comparatively investigated. Time-dependent models are proposed with satisfactory fit to the test results. A detailed comparison is
done using finite element analysis of a mass concrete sample to evaluate thermal cracking potential, by comparing the predicted
maximum restrained strain to the tested tensile strain capacity. The results indicate that fly ash performs better with lesser
thermal cracking potential than slag in concrete mixes designed for similar long-term strengths.

Keywords

• fly ash
• mass concrete
• slag
• thermal cracking
• thermal properties