Structural Details In Concrete

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To prevent the capillary rise of water into a slab-on-grade or belowgrade slab,an intervening layer of material must be added which is either impervious to moisture penetration or has a pore structure large enough to prevent capillary suction.Gravel and crushed rock are the materials most commonly used to provide a capillary break under a slab-on-grade or below-grade slab.