Proposed Behavioral Model for Deicer Scaling Resistance of Slag Cement Concrete

Abstract

This study was performed to define and evaluate specific mechanisms that control deicer scaling (freeze-thaw) resistance in slag cement concrete. Modified ASTM C672 procedures were used to measure the deicer scaling resistance of concrete made with grade 120 slag cement substituted for ordinary portland cement at equal mass replacement levels of 30 and 50%. Two types of coarse aggregate, two Type I portland cement brands, and several curing methods were studied. The effects of carbonation were found to be a main cause of reduced scaling resistance in slag cement concrete, as supported by trends among curing methods and by variations in the chemical composition of portland cement. For concrete cured under ambient and low-carbonation conditions, increased carbonation is correlated with an increase in the concrete’s scaling loss. These experimental results supported a proposed behavioral model linking cement hydration, concrete carbonation, and deicer scaling resistance. Decreased scaling resistance in concrete cured under moist conditions did not correlate with carbonation, but was likely caused by other factors related to continuous moisture present during curing.