SPECIAL ADMIXTURES

 

Sugar
 

Introduction: During the preparation of concrete work we add some components to create good quality in concrete. These components as known special admixtures. There are some types of  special admixtures.

 1. Water Proofing Admixtures
 2. Air Entraining Admixtures.
 3. Bonding Admixtures.
 4. Expansion Admixtures.
 5. Pazzolanic Admixtures.
 6. Bacterial Admixtures.

ADMIXTURES

ADMIXTURE
 

 Definition Of Admixtures: During the preparation of concrete without its compulsory components to create expecting of quality in concrete the extra components  mixing as known called admixture. We can say them also additives. Really during the preparation of cement we mix some components in cement is called Additives. When, the preparation of  concrete add some components in concrete is called admixtures. Some admixtures are here. Aluminum, Strict Acid and Polymer Emulsion.



                                                   
Question. Why we use admixtures in concrete?
Answer: We can get many benefits to use admixtures during the preparation of concrete. Some benefits
of admixture are under here.
1. we create extra qualities to use admixtures in concrete. Like that ,these admixtures also use to
reduce the resistance and defects on create high  temperature and low temperature in concrete work.
2. During the design work we enhance the setting time of concrete to use admixtures.
3. Some time we use admixtures in cement to reduce the setting time of cement for the repairing structures.
4. Some area they have water crises .There, we use admixtures to get good structure in minimum water. So,  for this purpose we mix in concrete  Lignosulfonic Acid and Alumina cement.

Retarders and Acceleraters

Accelerators
 

Accelerators:During the concrete work If the temperature

fall into freezing point in cold days. That time the concrete can not set in time and can't get complete strength .So we use accelerators 

to enhance heat in concrete for good setting. Often, this type of situations create on very cold areas. For this purpose we can use  Calcium chloride, Calcium Chloride, Calcium nitrate and Sodium chloride.



Retarders:When we have to do concrete work If the temperature of environment is very hot. So before concrete setting the water of concrete be decrease as result concrete lose his strength and durability. Therefore, we use many type of retarders to maintain the setting time of concrete water and we get good strength. This type of situations  create on hot areas. Some retarders are given under. Sugar and Carbohydrate.



Sugar