RIBVAULT
Rib vault
The intersection of two or three barrel vaults produces a rib vault or ribbed vault when they are edged with an armature of piped masonry often carved in decorative patterns; compare groin vault, an older form of vault construction. While the mechanics of the weight of a groin vault and its transmission outwards to the supporting pillars remained as it had been, the new use of rib vaults demonstrates the skill of the masons and the grandeur of the new ideas circulating at the introduction of Gothic architecture in the end of the eleventh century. This technique was new in the late eleventh century, for example in the roofs of the choir side aisles ...The above text is a snippet from Wikipedia: Rib vault
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