Evaluation of the usability of trachydacitic aggregate in rigid pavements in terms of strength and durability.

The research presented here investigates the usability of trachydacitic, an unexploited material that occurred in nature, as aggregate in the construction of concrete/rigid pavements under two different curing conditions. These curing conditions are specified as 28 days 20 ± 5 ˚C water curing and combined curing including 3 days 20 ± 5 ˚C water curing + 2 days dry oven curing at 200 ± 5 ˚C. Four different combinations of trachydacitic aggregated concrete as conventional concrete (CC) and high strength concrete (HSC), with steel fiber and fiberless, were produced at different cement and water contents. Mechanical (compressive and flexural strength), durability (freeze-thaw and sorptivity) and surface abrasion properties of studied concretes were tested for each curing condition. Additionally, SEM-EDX and XRD analyses were conducted to investigate the microstructural, elemental and mineralogical changes with curing. According to the test results, the highest compressive and flexural strength were obtained from the DLPB (Trachydacitic aggregated fibrous HSC) as 75,09 MPa and 10,09 MPa respectively after the combined curing process. Moreover, the combined curing process increased the resistance of concrete to freeze-thaw and water sorptivity, while reducing its resistance to Böhme abrasion. Microstructural investigations also revealed that HSCs have a denser structure compared to conventional concretes. As a result, it was determined that the powder form of trachydacitic aggregate, unlike its coarse form, can be used in HSC road pavement construction.