*2.3. Mechanical and Thermal Tests*

The flexural and compression tests were carried-out by the use of a MATEST device, Milan, Italy. Compression strengths were obtained on twelve semi-prisms (loading rate in the range of 2400 ± 200 N/s), deriving from the flexural tests carried-out on six prisms (40 mm × 40 mm × 160 mm) (loading rate in the range of 50 ± 10 N/s) [41].

An impact resistance device was made according to the ACI Committee 544 [44]. Specifically, the test was carried-out by dropping a weight of 4.50 kg from a height of 45 cm above a steel ball (63 mm diameter) placed centrally on the upper surface of the specimen. The energy absorbed by the sample before the fracture was obtained after evaluation of the number of blows on the sphere.

Thermal conductivity (λ) and thermal diffusivity (α) measurements were carried-out through an ISOMET 2104 device, from Applied Precision Ltd. (Bratislava, Slovakia). Before the tests, the mortars were dried to a constant weight, followed by final stabilization at room temperature. Specifically, a constant thermal flow was produced by a heating probe that was applied on the sample surface and the temperature was recorded over time. The thermal diffusivity and thermal conductivity parameters

were obtained by comparison between the experimental temperature values and the analytical solution of the heat conduction equation [45].
