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Admixtures for Concrete
Admixtures for Concrete
Admixtures Air-entraining admixtures Water-reducing admixtures Plasticizers Accelerating admixtures Retarding admixtures Hydration-control admixtures Corrosion inhibitors Shrinkage reducers ASR inhibitors Coloring admixtures Miscellaneous admixtures
Admixtures for Concrete
Air-Entraining Admixtures
Improve durability in concrete exposed to Freeze-thaw Deicers Sulfates Alkali-reactive environments
Improve workability
ASTM C 260 or AASHTO M 154ASTM C 260 or AASHTO M 154
Admixtures for Concrete
Frost Damage
Admixtures for Concrete
Scaled Concrete Surface
Admixtures for Concrete
Water-Reducing Admixtures
Reduce mixing water required to produce a certain slump
Reduce water-cement ratio Reduce cement content Increase slump
Primarily used to:Primarily used to:
Admixtures for Concrete
Water Reducing Admixtures
Type A ― reduces water content at least 5% tends to retard ― accelerator
often added Type D ―
reduces water content 5% min. retards set
Type E ― reduces water content 5% min. accelerates set
ASTM C 494 or AASHTO M 194ASTM C 494 or AASHTO M 194
Admixtures for Concrete
Water Reducer and Slump Loss
Admixtures for Concrete
Retardation (Initial Set)
Admixtures for Concrete
Retardation (Final Set)
Admixtures for Concrete
Mid-Range Water Reducing Admixtures
Reduce water content 6% to 12%
Reduce cement content Reduce water-cement ratio No retardation Improve placeability and
finishability
Admixtures for Concrete
Admixtures for Concrete
High-Range Water-Reducing Admixtures
Reduce H2O content 12% -30% Reduced W/C produces conc.
with: Compressive Strength > 70 MPa Increased early strength gain Reduced Cl ion penetration
ASTM C 494 or AASHTO M 194 ASTM C 494 or AASHTO M 194
Type F― Water Reducing
Type G ― Water Reducing and Retarding
Admixtures for Concrete
High-Range Water Reducer and Slump Loss
Admixtures for Concrete
HRWR, Water Reducer and Air Loss
0.048825.66.8B0.065593.86.4M0.040714.86.8NHigh-range
water reducer
0.040744.66.2H0.038674.77.0LWater
reducer
0.020563.05.4CControlMixture
Rate of air loss,
%/minute
Percent air
retained
Final air content,
% *
Initial air content,
%
*at point where slump falls below 25 mm
Admixtures for Concrete
Compressive Strength Development
Admixtures for Concrete
Plasticizers for Flowing Concrete
Essentially High-Range Water Reducer
SuperplasticizersAlso known as ―
ASTM C 1017Type 1 ―Plasticizing
Type 2 ― Plasticizing and Retarding
Admixtures for Concrete
Plasticizers for Flowing Concrete
Produce flowing concrete with high slump ( 190 mm [7.5 in.])
Reduce bleeding
Extended-slump-life plasticizer reduces slump loss.
ASTM C 1017ASTM C 1017
Superplasticizers
Admixtures for Concrete
Flowing Concrete
Admixtures for Concrete
Flowing Concrete as Thin Overlay
Admixtures for Concrete
Flowing Concretes and Slump Loss
Admixtures for Concrete
Retardation of Flowing Concrete (Initial Set)
Admixtures for Concrete
Retardation of Flowing Concrete (Final Set)
Admixtures for Concrete
Compressive Strength Development in Flowing Concrete
Admixtures for Concrete
Bleeding of Flowing Concrete
Admixtures for Concrete
Retarding Admixtures
Delay setting or hardening rate for:
Hot-weather concreting Difficult placements Special finishing processes
ASTM C 494 or AASHTO M 194, Type BASTM C 494 or AASHTO M 194, Type B
Admixtures for Concrete
Slump Loss at Various Temperatures
Admixtures for Concrete
Accelerating Admixtures
Accelerate the rate of: Hydration (setting) Early-age strength gain
ASTM C 494 or AASHTO M 194, Type CASTM C 494 or AASHTO M 194, Type C
Calcium chloride accelerators: Increase drying shrinkage,
potential reinforcement corrosion, potential scaling
Darken concrete
Admixtures for Concrete
Maximum Chloride-Ion Content
0.30Other reinforced concrete construction
1.00Reinforced concrete that will be dry or protected from moisture in service
0.15Reinforced concrete ex-posed to chloride in service
0.06Prestressed concreteType of member
Maximum water soluble chloride-ion (CI¯) in
concrete, percent by mass of cement
Admixtures for Concrete
Corrosion Inhibitors
Control Corrosion of Steel Reinforcement
Dosage dependent on anticipated chloride level
Admixtures for Concrete
Shrinkage-Reducing Admixtures
Admixtures for Concrete
ASR Inhibitors—Lithium Carbonate
Admixtures for Concrete
Coloring Admixtures (Pigments)
Admixtures for Concrete
Liquid Admixture Dispenser
Admixtures for Concrete
Videos 1/2
Air-Entraining Admixture Water Reducer
Admixtures for Concrete
Videos 2/2
Retarder/Accelerator Admixture Dispenser