Abstract:

Roller compacted concretes are a building material that can be produced using the raw materials used in traditional concrete production, which allows working with dry mix with the production technique, and is preferred for use in road and dam constructions. In this experimental study, the effect of using different aggregates in roller compacted concretes on the freeze-thaw resistance of concrete was investigated. Dolomite, basalt, marble and limestone were used as coarse aggregates in the production of roller compacted concrete. In roller compacted concrete production, concrete mixtures with zero slump value and water/cement ratio of 0.35 were prepared, and these mixtures were compressed in two stages and placed in the mold. The specimens were demolded 24 h after casting and moist-cured. The water-saturated cube specimens, which were kept in lime-saturated water for 90 days, were subjected to repeated freeze-thaw cycles of 12 hours at +20°C and 12 hours at -20°C. At the end of 25, 50 and 75 cycles, the weight and ultrasonic pulse velocity (UPV) of roller compacted concrete specimens were recorded. At the end of 75 cycles, the average compressive strength, standard deviation and coefficient of variation values of the specimens were determined. At the end of 75 freeze-thaw cycles, the compressive strength loss was determined as 12.2% in the samples produced with dolomite aggregate, 13.8% in those produced with basalt, 3.3% in those produced with marble, and 4.6% in those produced with limestone. As a result of the experimental study, it was observed that the aggregate type was effective on the freeze-thaw resistance of the roller compacted concretes.

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