*3.3. Dilatometry Test*

Numerous materials present dimensional variations after being exposed to a heating period, presenting dimensional variations under the effect of the contraction and expansion phenomena in their structures. These variations take place due to physical and chemical events that occur in the structures and chemical composition of their materials. In the development of engineered stone, thermal transformations occur in the curing stage because of the matrix/waste polymerization reaction [31].

The ENS, composed of glass and quartz in the epoxy matrix, had excellent test stability and resistance, probably due to the aggregate's properties and characteristics at high temperatures. Figure 2 presents the ENS-15 dilatometry analysis.

In Figure 2, one can observe the structural behavior of ENS-15 in a heated environment in a range of temperature from 0◦ to 1000 ◦C, identifying the structural phenomena presented such as the body temperature at the exact moment.

In the range of 0–300 ◦C, it is possible to see the adaptation of materials to the heated environment, favoring pore expansion and the structure's moisture loss, in addition to a molecular chemical activation, which causes movement expanding the entire structure. Owing to the adaptation, at 338 ◦C, the structure contracts, which is followed by an expansion at 362.6 ◦C and a significant decline at 382.4 ◦C, a temperature where the resin begins to decompose, with a weight loss demonstrated in previous works [17].

According to Silva et al. [17], the epoxy resin thermogravimetry curve registers the first 70% weight loss at about 380 ◦C due to the resin's decomposition. Subsequently, at 382.4 ◦C, there is a weight loss that continues until the end of the process, at 550 ◦C [17]. After 600 ◦C, the structure undergoes another contraction, and there is a total weight loss because of the resin and the melting temperature of the waste glass, which is around 600–1117 ◦C, and of the quartz dust, which, at around 870 ◦C, becomes tridymite, a high-temperature silica polymorph [17,31].

**Figure 2.** Dilatometry curve of ENS-15.
