Rapid hardening cement• Finer than opc provide greater surface area for action with water• Gain strength early• 1 day strength of this cement is equal to 3 day srength of 43 grade cement• Used where a rapid strength devlopment is required• Rapid strength gain is accomplained by higher rate of heat devlopment useful in cold enviourment concereting• Not suitable for hot concereting• Prefebricated structure
Low heat portland• Less recative than opc• Initial setting time is greater than opc• Slow devlopment• Used in mass concereting:dam• Slow devlopment of strength less heat
Sulphate resisting cement• Contain silicate content is called sulphate resisting cement• Expansion within hardned structure of cement paste result in crack is called sulphate attack• Used marine enviourment
Masonary cement• Finely gridned• Produce smooth ,plastic surface
Water proof cement• Water proof substance is added in opc• Calcium sterate,aluminium sterate,gypsum with tannic acid
White portland cement• Amount of iron oxide governing greyiesh colour is reduced• Chalk,highly purified lime stone as raw material• Finer than gray cement• Used to minimise temperature effect
Coloured portland cement• Pigment is added for achiving different colours• 10% pigment is added• Permanent pigment should be used so that colour remains for a long time• For decoration purpose
Non portland based cement• High alumina cement• Super sulphate cement
High alumina cement• Very rective• Very high early strength• 80% at 24 hours• Resestive to chemical attack• Rise of temperature
Super phasphate cement• Made by mixing 80-85% well granulated slag with 20% sulphate• Initial setting time 2.5-4 hours,final setting time4.5 to 7 hours• Heat of hydration is very low• Used in foundation which is used in aggressive condition• Requires great care when used in cold weather
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