# Performance of Eco-Friendly Zero-Cement Particle Board under Harsh Environment
## 3 Results
### Failure Mode  
Figure 7 illustrates the failure modes of the alkali-activated particle boards and various degrees of damage. Obviously, the surfaces of all specimens exhibited rough textures, and there was an increase in the extent of corner loss in the specimens subjected to freezing-thawing cycles. For instance, considering the FT300 specimen as a representative, after 10 cycles, its surface underwent minimal alteration compared to the NC300 specimen. However, after 25 freezing-thawing cycles, the specimen's surface became notably rougher. This was accompanied by the detachment of small mortars that fell off from the corners and the emergence of micro-cracks on the surface. Additionally, noticeable swelling was observed on the specimens' surfaces due to agro-waste in the material composition. This swelling became more pronounced after 25 cycles of freezing and thawing conditions.  
Figure 6: The result of the water absorption of the particle board with different slag contents and curing conditions.  
Figure 7: Failure rate of alkali-activated particle board specimens. (Destroyed: significant damage induced by exposure conditions, fail to parts).  
Furthermore, the amount of slag content exerts a notable influence on the deterioration process of the specimens. At the same freezing-thawing cycles, it is evident that lower amounts of slag within the particle board specimens lead to more pronounced degradation. This trend is illustrated in Figure 7, where the NC400 specimen displayed negligible changes (Green Dashed). The specimen exhibits only slight swelling with no noticeable alterations. In contrast, the 25 FT200 specimen experienced significant deterioration, while the 25 FT300 and 25 FT400 specimens demonstrated even less pronounced degradation when compared to the specimens subjected to standard curing conditions.  
Upon the completion of 25 freezing-thawing cycles, discernible damage became apparent on the edges of the 25 FT300 prismatic specimens. Furthermore, the edges of the 10 FT300 specimens began to peel off following 10 freezing-thawing cycles. Remarkably severe surface damage was observed in the case of the 10 FT200 and 25 FT300 specimens. Notably, the mortar layer on the surface of the 25 FT300 specimens had entirely dislodged, leaving the agro-waste aggregate exposed. The degradation of the 10 FT200 specimen was even more pronounced, with substantial peeling of the concrete edges and wider cracks on the surface.  
For the wetting and drying cycles, a higher content of slag was found to contribute to a reduced level of degradation in the particle board specimens, and this was similar to the trend observed during the freezing and thawing cycles. Figure 6 illustrates a discernible contrast in degradation severity between the 25 WD200 (Red Dashed) and 25 WD400 specimens. The amount of degradation witnessed during the wetting and drying cycles substantially exceeded that observed during the freezing and thawing cycles. For instance, the 25 WD300 specimen showed more degradation than its freezing and thawing cycle counterpart, 25 FT300. Upon closer examination, it became evident that after undergoing 25 cycles of curing under wetting and drying conditions, the surfaces of the specimens exhibited significant changes. The mortar layer underwent complete detachment, forming small pits, thereby exposing the agro-waste on the surface. Furthermore, at the edges of the specimens, severe peeling of the alkali-activated material occurred, resulting in wider cracks on the surface.