A materials science researcher presents findings at a civil engineering symposium regarding post-eruption resource utilization:
"Following the 2021 Tajogaite eruption on the island of La Palma, our research team investigated constructive applications for accumulated basaltic tephra. We evaluated substituting traditional Portland clinker with finely pulverized volcanic ash in structural mortar formulations. In controlled laboratory trials, mortar blends containing a 25% volcanic ash replacement demonstrated a 14% increase in compressive strength following a standard 90-day curing period, resulting from dense calcium-aluminate-silicate hydrate gel formation. Furthermore, replacing clinker at this specific ratio lowered the material's embodied carbon footprint by 210 kilograms of carbon dioxide per metric ton. However, when ash proportions exceeded the 35% threshold, early-stage setting times were considerably delayed, requiring the introduction of alkaline sodium silicate activators to accelerate hardening during the initial 48 hours."
Based on the presentation, what specific structural improvement resulted from utilizing a 25% volcanic ash replacement in the mortar?
- AA 35% decrease in overall curing time under standard laboratory conditions
- BAn elimination of the requirement for chemical activators during the first 48 hours
- A 14% rise in compressive strength after ninety days of curingCevap
- DA reduction of 210 kilograms of carbon dioxide in the early hydration phase