Which structural vulnerability increases when a Roman arch lacks sufficient abutment mass?

💡 Explanation

When an arch lacks sufficient abutment mass, outward thrust increases because the arch's geometry converts vertical loads into horizontal forces that must be resisted. Therefore outward thrust causing collapse results, rather than slippage, cracking, or creep which require different material or environmental factors.

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• During Mesopotamian bronze casting, which consequence occurred from incomplete removal of slag inclusions?
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