Thermal deformability of recycled self-compacting concrete under cyclical temperature variations

Recycled Concrete Aggregate (RCA) has greater elasticity than natural aggregate, due to the presence of adhered hydrated mortar in the coarse fraction, and mortar particles in the fine fraction. To evaluate this aspect under temperature variations, four Self-Compacting Concretes (SCC) made with 100% coarse and/or fine RCA were subjected to cyclical temperature variations between 70 °C and 20 °C and between −15 °C and 20 °C. The addition of RCA, especially in the coarse fraction, increased the thermal deformability, although the difference tended to decrease with the number of cycles, especially in positive temperature variations. This study concludes that the traditional upper limit of the linear thermal expansion coefficient for concrete (1.2·10⁻⁵ °C⁻¹) is also suitable when RCA is incorporated.