الفهرس Only 14 pages are availabe for public view
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Abstract
The chemical materials used as water repellent admix-tures are able to form a thin hydrophobic layer with the pores and voids and on the surface of the concrete . This water repellency conferred on the concrete is only effective in preventing water from entering the surface when the applied pressure is small , e. g . rain fall in windy conditions , or capillary rise . Mineral oils , vegetable oils , paraffin waxes , long chain fatty acids or their salts , hydrocarbon resin and bitumen are claimed to exhibit this property .