CONTENT
01.
02.
03.
ADDITIVES
ADMIXTURES
DIFFERENCE BETWEEN
ADDITIVES AND
ADMIXTURES
DEFINITION
TYPES
USES
EXAMPLES
ADVANTAGES
DISADAVNATGES
ADDITIVES
Additives are chemical components added to
cement during manufacturing to give new
properties or to enhance existing properties.
TYPES OF ADDITIVES
●Accelerators
●Retarders
●Dispersants
●Fluid loss control agents
●Weighting agents
●Extenders
●Loss circulation control agents
●Speciality agents
TYPES OF ADDITIVES
ACCELERATORS:
1. Itspeeds upthe early stage of hydration whichshortens the setting
time of thecement
2. Itincreasestheearly strength of cement, and saves expensive rig
time.
3. Acceleratorsdo not increasethe ultimatecompressive strengthof
cement butpromote rapid strength development.
4. It is used tocounter attackthesetting delaycaused by other
additives such asdispersants and fluid loss agents.
5.Calcium chlorideis the mostly used.
RETARDERS:
1. It is todecreasethespeed of cement hydration.
2. Itinhibit hydrationanddelay setting, allowing sufficient time for
slurry placement indeep and hot.
3. Itincreasesthe thickening times for pumping the cement into place.
TYPES OF ADDITIVES
DISPERSANTS:
1. Itcontrols the slurry flowand helpinduce fluid motionof cement slurry atlow pumping
rates.
2. It allowswater contentofcementto belowered withoutmaking itdifficult to pump.
3. Itneutralize positive chargeson cement particles , they effectivelybreak
upaggregatesintoindividual particles.
4. At right concentration they canimprovecementhomogeneityandlowerit’spermeability.
TYPES OF ADDITIVES
FLUID-LOSS AGENT:
1. They are also known as filtration control additives.
2. When cement is placed across a permeable formation under
pressure, afiltration process is created. Water escapes into the
formation and the cement isleft behind.
3.If this fluid loss is not controlled, thickening time and density of
the slurry willchange and the cementing job could fail.
4. To prevent water loss and slurry characteristics this fluid-loss
control agents areused.
5. There two types of fluid loss agents are used finely divided
material and watersoluble polymers
TYPES OF ADDITIVES
WEIGHTING AGENTS :
1. In high pressuregas wellor unstablewellbores,high density
fluidis required.
2. The easy way is toincrease cement densityis
toreducetheamount of waterfrom cement but itmakestheslurry
difficult to pumptherefore weighting agentsare used
3. They havespecific gravity greater than the cement, consistent
particle sizedistribution andlow water requirement.
4. Chemicallyweighting agents are inertin the cement slurry and do
not interferewith logging tools.
5. They areusedfor cementinghigh pressure formations.
6. If theslurry density is too lowit might getunstable.
USES
•Enhancement of Workability:
•Plasticizersand Superplasticizersare used to improve the workability of concrete without increasing the water
content. This helps in easy handling, especially in large-scale construction projects like bridges, dams, and high-
rise buildings.
•Control of Setting Time:
•Retarders(used in hot climates) and Accelerators(used in cold climates) help manage the setting time of
concrete. Retarders are especially useful in India’s warmer regions to avoid premature setting during
transportation. Accelerators are used to speed up the curing process in cooler temperatures.
•Improvement of Durability:
•Corrosion Inhibitorshelp protect rebars from corrosion, which is especially important in India due to the high
humidity and exposure to coastal environments, which accelerate the corrosion process.
•Air-Entraining Agentsare used to improve concrete's resistance to freezing and thawing cycles, but they also
help in areas of heavy rainfall or humidity in coastal regions.
USES
•Waterproofing:
•Types: Crystalline admixtures, Hydrophobic pore-blocking agents, Densifiers
•Function: Reduce water permeability, enhance durability, and prevent corrosion in reinforcement
•Uses: Basements, water tanks, bridges, and marine structures
•Example: Xypex, Kryton, and Fosrocwaterproofingadmixtures
•Improvement of Strength:
•Pozzolanic Materials, such as Fly Ash, Ground Granulated Blast Furnace Slag (GGBS), and Silica Fume, are added
to increase the long-term strength and durability of concrete. These materials are often used in large
infrastructure projects like highways, bridges, and industrial buildings in India.
MANUFACTURERS OF ADDITIVES
○Product: Superplasticizers, retardants, accelerators (available in 10/25L
drums)
○Product: superplasticizer(high performance, low viscosity) AURACAST
270M
Perma Const. Aids
FOSROC
MANUFACTURERS OF ADDITIVES
○Product:MasterCem
○The Dow Chemical Company
○Product: WALOCEL MKW for cement render, DOW latex powders (DLP),redispersiblepolymer
powders (RDP) for cement-based tile adhesives
○Product: USG Snow White CalciumSulfateFiller, USG CAS-20-4 CalciumSulfateFiller,
USGTerra Alba No.1, USG Industrial Filler No.1, and USG Industrial Ground Gypsum.
○Sterling auxiliariesPvt.Ltd.
○Product: POLYCARBOXYLATE ETHERS (PCE) –for Slump reduction and Compressionstrength
BASF
USG Corporation
ADMIXTURES
It is usedas on ingredient of concrete or mortar and added to the batchimmediately
before or during its mixingto modify one or more of the properties of concretein the
plastic or hardened state.
TYPES OF ADMIXTURES
MINERAL:
•FLY ASH: A byproduct from burning coal in power plants, it enhances workability and reduces water demand.
•SILICA FUME: A byproduct of silicon metal production, it improves strength and durability by filling voids in concrete.
•GROUND GRANULATED BLAST FURNACE SLAG (GGBFS): A byproduct of steel manufacturing, it enhances resistance to
chemical attack and improves long-term strength.
•RICE HUSK ASH: An agricultural waste that can enhance the pozzolanic properties of concrete.
CHEMICAL:
SET RETARDING:
•These admixtures are used where setting time of concrete need to be delayed hence workable for long duration.
•It delays the hydration process but doesn’t affect the eventual process.
•Used in high temperature zones where concrete will set quickly.
•Calcium sulphate, sugar, salt, cellulose, ammonium, ferrous & ferric chloride, hydro carboxylic acid and their salts are
used as retarders.
TYPES OF ADMIXTURES
AIR ENTRAINING:
•It is to increase the durability of concrete under freezing and thawing conditions.
•When added to concrete mix, It will form small stable bubbles of air to form
•uniformly through a concrete mix
•also improve the workability of concrete, prevents segregation and bleeding, improves the
chemical resistance of concrete.
•Most used air entrainment admixtures are vinsolresin, darex, Teepol,etc.
•These admixtures are actually made of Natural wood resins, alkali salts, animal and vegetable fats
and oils etc.
TYPES OF ADMIXTURES
WATER REDUCERS:
•It minimizes the amount of water required in a concrete mix.
•These are also known as plasticizers and these are classified into:
•Calcium and sodium are commonly used plasticizers, new generation superplasticizers are acrylic
polymer based, polycarboxylate, etc.
Water-Reducing Benefits & Required
•Water Capacity Superplasticizers reduce water by up to 30%, improving strength without sacrificing
workability Ideal water-cement ratio: 0.4 -0.6 depending on structurerequirements
ACCELERATORS:
•It increases the rate of hydration of concrete.
•They speed up the process of initial hardening of concrete.
•There are useful in fast-track construction such as early removal of form work, less period of curing,
emergency repair works , for construction in low temperature region.
1.Plasticizer-reduces the water demand upto10%.
2.Mid -range plasticizer -reduces the water demand up to 15%.
3.Super -plasticizer -reduces the water demand upto30 %.
USES
1. Improvement of Workability
Plasticizers and Superplasticizers: These increase the flowability and workability of concrete, making it easier to mix, transport,
and place. They are particularly useful for complex moldsor when the mix is heavily reinforced.
Use Case: High-rise buildings, large-scale infrastructure projects, and concrete elements with dense reinforcement.
2. Control of Setting Time
Accelerators: Speed up the setting time of concrete, allowing for faster curing, especially in colder weather conditions.
Retarders: Slow down the setting time, which is useful in hot climates or for projects that require longer handling and
transportation times.
Use Case: Cold-weather concreting (accelerators) and hot-weather concreting or long-haul projects (retarders).
3. Enhancing Durability
Corrosion Inhibitors: These reduce the risk of steel reinforcement corrosion, making concrete more durable in aggressive
environments like marine areas or areas with high chloride content.
Air-Entraining Agents: Improve freeze-thaw resistance by creating microscopic air bubbles in the concrete, which helps prevent
cracking due to freezing and thawing cycles.
Waterproofing Agents: Reduce water penetration, protecting concrete from moisture-related damage.
Use Case: Coastal structures, industrial plants, water treatment facilities, and foundations exposed to moisture.
USES
4. Improving Strength
Pozzolanic Additives (Fly Ash, Silica Fume, GGBS): These materials enhance the long-term strength and durability of concrete
by improving its density and chemical resistance.
Use Case: High-performance concrete used in bridges, highways, dams, and large buildings requiring high compressive
strength.
5. Shrinkage and Cracking Control
Shrinkage-Reducing Admixtures: These help reduce the shrinkage of concrete during the curing process, minimizing the
potential for cracks, especially in large pours.
Use Case: Slabs, pavements, and floorings in large industrial or commercial buildings.
MANUFACTURERS OF ADMIXTURES
•FOSROC
Product: superplasticizer(high performance, low viscosity) AURACAST 270M
•BASF
Product: MasterCem
•The Dow Chemical Company
Product: WALOCEL MKW for cement render, DOW latex powders (DLP), redispersiblepolymer powders
(RDP) for cement-based tile adhesives
•USG Corporation
Product: USG Snow White Calcium SulfateFiller, USG CAS-20-4 Calcium SulfateFiller, USG Terra Alba
No.1, USG Industrial Filler No.1, and USG Industrial Ground Gypsum.
•Sterling auxiliaries Pvt.Ltd.
Product: POLYCARBOXYLATE ETHERS (PCE) –for Slump reduction and Compression strength
ADVANTAGES OF ADMIXTURES
•They enhance the workability of concrete. Admixtures imparts early strength in concrete.
•Admixtures reduce the early heat of hydration and overcome thermal cracking problem in concrete. If there is
a more heat of hydration then cracks can propagate in fresh concrete.Admixturesimprove the resistance
against freeze-thaw effect on concrete.
•Concrete admixtures boost sustainability by:
1.Reducing cement:Less water needed means less cement, lowering CO2 emissions.
2.Using waste:Enables use of industrial byproducts like fly ash, cutting carbon footprint.
3.Bio-based options:Some use renewable materials, replacing oil-based components.
4.Improving lifespan:Enhances durability, reducing repairs and resource use.
•Concrete admixtures can accelerate the setting time as well as there are admixtures that decelerate concrete
setting time.
•There are some admixtures that act as anti-bacterial agents.
•RMC (Ready-Mix Concrete) & Its RoleFactory-made concrete ensuring uniform qualityReduceswastage,
increases efficiency, and is widely used in large-scaleprojects
DISADVANTAGES OF ADMIXTURES
•Increased dosage initially makes the concrete mix look workable and increases the slump, but the slumpdrops
very quick, thus making the mix unsuitable for working.
•Concrete for slipformingcan be ruined by an excessive amount of PCE additive. Fluid occurs first, and then the
mixture becomes sticky and forms hexagon. Overdosing, temperature, cement problems, poor aggregates, or
an excess of retarders are the causes of this. Fix it with meticulous testing and oversight.
•In case of form finished concrete the high range water reducing superplasticizer results discolourationof the
concrete and gives rise to air voids on the exposed surface.
DIFFERENCE BETWEEN ADDITIVES ADMIXTURES
ADDITIVESARE CHEMICALCOMPONENTS ADDED TO
CEMENTBEFORE MANUFACTURING TO ENHANCE THE PROPERTIES
OFEXISTING COMPONENTS
ADMIXTURESAE CHEMICALCOMPOUNDS THAT ARE ADDED
TOCONCRETE MIXTURES WHILE MIXING TO GET NEW PROPERTIES
ADDED TO CEMENT ADDED TO CONCRETE
ADDED TO CEMENT WHILE MANUFACTURING ADDED TO CONCRETE BEFORE OR DURING MIXING
EG. ACCELERATORS, RETARDERS, DISPERSANTS, FLUID LOSS
CONTROLAGENTS ETC
EG.FLY ASH, SILICA FUME ETC.
ADDITIVES ADMIXTURES
ON SITE TEST
•Slump Test: Measures workability and water-reducing efficiencyWater
•Absorption Test: Determines permeability reduction
•Compressive Strength Test: Evaluates strength gain due to additivesArchitecturalUse
Cases
ARCHITECTURAL CASES
•Burj Khalifa: Used high-range superplasticizers to achieve pumpable concrete for extreme
•heights Lotus Temple: Used white concrete with admixtures to maintain aesthetic appeal
and strength
•Underwater Structures: Water-reducing agents and corrosion inhibitors for
marineconstruction