Long-term scaling performance of concretes containing supplementary cementing materials

As part of a research program investigating the effects of supplementary cementing materials (SCMs) on the performance of concretes subjected to deicer salt scaling, a field trial was initiated in 1994. A series of six in-ground pavement slabs were cast with concretes containing various proportions of SCMs and exposed to a cyclic freeze/thaw environment, deicer salt application, and regular heavy truck loads for a period of 12 years. The concretes consisted of a control mix with 100% portland cement, slag mixes containing 25, 35, and 50% blast furnace slag, a fly ash mix containing 15% Class C fly ash, and a ternary blend mix with 25% slag and 10% fly ash. Two sets of laboratory deicer salt scaling specimens were prepared concurrently with the in-ground slabs; one was immediately cured and tested in accordance with the applicable standard, whereas the second set was left on site and subjected to the same exposure conditions as the in-ground slabs for 4 months (prior to freezing) before testing. Damage exhibited by the in-ground slabs and the 4 month exposed scaling slabs was far less significant than that produced by the specimens subjected to standardized testing.