(Universidad Central "Marta Abreu" de Las Villas, 2019) Lichtblau, Sandra Marina; Martirena Hernández, José Fernando; Linsel, Stefan
Recycled concrete aggregate from unknown sources has been characterized. A new treatment
method of recycled aggregate, called encapsulation or coating, has been used to enhance the
properties. With the designed experimental program, it has been proved, that the encapsulation
treatment of the coarse fraction from 10-5 mm of recycled concrete aggregate has a positive
effect on the physical properties of the aggregate such as water absorption, as well as in concrete
properties of a 100 % recycled aggregate concrete (RAC). With the incorporation of the coated
aggregate, compressive strength has increased. Microstructural analysis shows a denser
interfacial transition zone (ITZ) between the encapsulated aggregate and the cement paste
compared to the ITZ between a non-encapsulated aggregate and cement paste. The subsequent
durability testing program compared the behaviour of different recycled aggregate concretes
with natural aggregate concrete (NAC) under three environmental conditions. The pore
structure and migration properties of concretes has been assessed during up to 30 month of
exposure, by using several durability test methods. Test results show a viable possibility for
concretes entirely produced with recycled concrete aggregate, when the encapsulation treatment
is applied