Endaver

Types of cement:

1. Ordinary portland based cement

2. non opc cement

Ordinaray portland cement• Rapid hardening cement• Low heat portland

cement• Sulphate resisting

cement• Masonary cement• Water proof portland

cement• White portland cement• Coloured portland

cement

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