**3. Results and Discussion**

*3.1. Slump*

As shown in Table 4 and Figure 2, with a fixed GGBFS of 20%, 1% of waste PE, and W/B ratio of 0.4, 0.5, and 0.6, corresponding slumps of cement mortar were 1.5, 2.6, and 3.8 cm, respectively. The slump of cement mortar reveals an upward trend. Furthermore, the slump was 1.9~1.2 cm with a W/B ratio of 0.4 and 1~4% addition of waste PE fiber material, and it can be observed that the slump tends to decrease with the increase in the addition of waste PE fiber material. The slump is observed to increase with the W/B ratio. As the waste PE absorbs water, it absorbs the free water in the mortar; when the content of waste PE in the mortar increases, the slump decreases accordingly. Therefore, the slump increases as the W/B ratio increases and the waste PE content decreases, as shown in Table 4.

**Table 4.** Slump and slump ratio of cement mortar with different W/B ratios and waste PE (unit: cm).


\* SR: Slump ratio of PE material added specimen to the control specimen without PE material added.

**Figure 2.** Slump of cement mortar with different W/B ratios and waste PE.

Regarding W/B = 0.4, the slump ratio of the specimen with 1% PE fiber material added to the control specimen without PE fiber material added was 0.79, as shown in Table 4. Still, the decreasing trend of the slump was slowed down with the increase in PE material added, and the maximum slump ratio was 0.63, which occurred in the specimen with 4% PE material added. Similarly, at W/B = 0.5 and 0.6 series, the slump also showed a

decreasing trend with the increase in PE addition. Therefore, the effect of PE addition on the deterioration of fresh mix properties could be improved significantly by W/B. With 2% PE addition, the slump of W/B = 0.5 increased significantly from 1.3 cm to 2.5 cm compared with that of W/B = 0.4, which was 1.92 times. The results showed that the PE fiber material addition has little effect on the fresh mix properties. Therefore, the fresh mix property test results show that the cement mortar can be added with PE fiber material to achieve the impact of waste minimization.
