There are two types of cement: Grey cement - used only for construction purposes, and White cement - for a variety of uses like mosaic flooring, in cement paints, and as a primer for paints, etc. Grey cement costs more than white cement because the production costs and excise duty are higher. White cement also sets faster. For grey cement, the strength after 28 days of setting is taken as the final strength. White cement achieves this strength in about three days time.
The cement has to be fine in texture. It should be smooth, dry and cool to touch. Fineness gives more strength to cement because the chemical reactions take place faster. Do not buy cement which is in rough, granular lumps. This indicates it has been exposed to moisture. Cement is now available in grades and is easier to buy . For eg: 53 grade cement implies that a cube of cement can withstand a pressure of 530 kgs per square centimetre. You can check this on a compressing machine. This is called the breaking strength of cement. Good cement hardens faster. You can therefore remove the scaffolding / formwork sooner than usual. You save on centering and labour costs, and your building is ready much faster.
(via ChennaiBest.com)
No comments:
Post a Comment