*3.11. Microscopic Analysis*

As shown in Figure 12, at the age of 7 days, for a W/B ratio of 0.5 and waste PE contents of 1%, 2%, 3%, and 4%, the number of fibers inside the cement mortar specimen is significantly increased. According to the EDS analysis, the main elements were O, Ca, C, and Si. The waste PE is found to increase the specimen porosity, verifying that the compressive strength is decreased with increasing waste PE content.

**Figure 12.** SEM of cement mortar with different waste PE (×1000) (day 7, W/B ratio of 0.5).
