Which defensive outcome arose from the Roman adoption of concrete in fortification construction after iterations in hydraulic infrastructure?

💡 Explanation

When the Romans adopted concrete, the pozzolanic reaction created a durable, weather-resistant material that, when used in fortifications, could absorb more impact from siege weaponry like ballistae because of its distributed mass and internal damping rather than tensile strength alone. Therefore increased defense resulted, rather than reduced costs or maintenance which would require easily sourced labor and reusable design/structure.

• Which structural risk increases when Roman roads experience thermal expansion during seasonal heat cycles over decades?
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• Which outcome accelerates depletion of soil nitrogen on pre-Columbian chinampas with intensive maize farming?
• During siege warfare, which countermeasure reduced effectiveness of Roman ballista siege engines targeting city walls?
• Which effect limited Mesopotamian shaduf irrigation systems from irrigating higher elevations near riverbanks?
• Which long-term consequence resulted from vitrified fort construction techniques used by the Picts?