They replaced 5%, 10% and 15% in volume of natural aggregate in the concrete mixes by an equal volume of three differently shaped and sized PET-aggregates.

 

Compressive strength and modulus of elasticity deteriorate

 

The results indicate that the slump of fresh concrete increases slightly with the incorporation of pellet-shaped PET-aggregate. Flakier plastic aggregate sharply decreases the slump of the fresh concrete and it further decreases if the content and size of this type of PET-aggregate increase. The compressive strength, tensile splitting strength, modulus of elasticity and flexural strength of concrete deteriorate due to the incorporation of PET-aggregate and the deterioration of these properties intensifies with increasing content of this aggregate.

 

Abrasion resistance of concrete mixes shows good results

 

Differences in size, shape and texture of PET-aggregates change the water to cement ratio as well as the slump of fresh concrete mixes, which ultimately change the mechanical behaviour. Flaky PET-aggregates bridge the two separated concrete pieces and therefore prevent concrete from breaking apart after failure. The abrasion resistance of concrete mixes containing various types of PET-aggregate is better than that of the reference concrete. The abrasion resistance of concrete with incorporation of various types and contents of PET-aggregates can be related to its compressive strength.