Influence of Blast Furnace Slag on the Durability Characteristic of Road Concrete Such as Freeze-Thaw Resistance

The present paper assesses the state of degradation from the action of the freeze-thaw phenomenon on the new cement mixes made with addition of granulated and ground blast furnace slag (GGBS) but also with partial replacement of the natural aggregates with different percentages of artificial aggregates from ungranulated and crushed blast furnace slag (ACBS).The purpose of this study is to evaluate the behavior of road concrete mixtures versus blends made with conventional materials for an extended period of repeated freeze-thaw cycles. Thus, from 100 freeze-thaw cycles, as is commonly practiced for road concrete, the test period was extended to up to 150 cycles and then up to 300 freeze-thaw cycles. Three blends were made with 15% addition of slag powder of less than 63 μm and 20%, 40%, 60% of artificial aggregates of 0/4mm that replaced the natural sand.The variation of the dynamic elastic modulus at 150 cycles and, respectively, at 300 freeze-thaw cycles was tested by the non-destructive ultrasonic methodon laboratory samples. It was thus noticed that in the mixture in which 15% added slag powder and 60% artificial aggregates were incorporated the durability performance was affected, especially at 300 freeze-thaw cycles. However, in the mixture with 15% added slag powder and 40% artificial aggregates the durability characteristics improved compared to the previous blend and in the mixture with 15% addition of slag powder and 20% artificial aggregates the results were much better than those obtained in blends made with conventional materials.