The density and water absorption of the cured pellets was determined by exposing the pellets to drying at 80°C or underwater storage. Each step of the procedure (wetting/drying) lasted 24±1 h. The density of the pellets was determined on the saturated pellets based on Archimedes' principle. The tests were carried out on three fractions separately: 8-12 mm, 12-16 mm and 16-20 mm. For each fraction, triplicate samples were collected from a larger batch, each containing at least 50 grams of cured pellets (about 60 pellets, 50 pellets or 20 pellets in a sample for each of the three size fractions, respectively).