Superplasticising Admixture


Uses

  • To produce high workability concrete without loss of strength. To promote high early and ultimate strengths by taking advantage of water reduction whilst maintaining workability.

  • To produce high quality concrete of improved durability and impermeability.

  • At higher dosages, advantages can be taken of the retardation of initial setting time of concrete especially in large pours.

ADVANTAGES

  • Pumpability: Increased workability provides easier and quicker placing and optimum compaction. Aids concrete placement by pump.

  • Increased strength: Provides higher strength without increase in cement content or reduction in workability. Ideal for precast concrete production.

  • Improved quality and cohesion: Reduce rate of workability loss normally associated with superplasticiser. Reduces shrinkage cracking because of lower water cement ratio. Makes the concrete water impermeable.

  • Bleeding and segregation minimized: Improves durability and impermeability of concrete.

  • Chloride free: Safe in prestressed concrete production.

Description

PLAST-S 337 is based on a blend of specially selected organic polymers. It is supplied as a dark brown liquid, instantly dispersible in water.

PLAST-S 337 disperses the cement particles

effectively in the concrete mix and hence exposes a larger surface area to the hydration process. This effect is used either to increase the strength or to produce high workability concrete or reduce cement content of concrete or to retard the setting time of concrete.

Technical support

Sigmacheme advice can be sought on mix design aspects especially to produce high workability concrete without segregation. Sigmacheme provides advisory service for on-site assistance and guidance on evaluation of trials and usage.

Properties
Specific gravity : 1.18 to 1.20 at 27°C Chloride content : Nil to IS:456 Air entrainment : Approximately 1% additional air is entrained. Setting times : At higher dosage levels without water reduction, retards setting times 1 - 2 hours approximately.
Compatibility with cements:

Can be used with all types of Portland and slag cement except High Alumina Cements. PLAST-337 is compatible with other Sigmacheme admixtures but it is recommended that admixtures if used in combination are added separately.

Workability:

PLAST-S 337 can be used to produce collapse slump concrete without reducing the water content However, minor adjustments to mix design may be required to produce flowing concrete to prevent bleeding and segregation.

Permeability:

Reduced water/cement ratio increases density and improves impermeability Improved workability facilitates easy placing and good compaction.

Cohesion/segregation:

The possibility of bleeding and segregation will be reduced because of increase in cohesion. A uniform close textured surface without sand runs or voids can be produced.

Pumpability:

PLAST-S 337 will aid pumping of concrete by providing lubrication to cement particles and reducing line friction.

Application instructions

The optimum dosage of PLAST--337 should be determined by site trials with a specific concrete mix to facilitate measurement of effects of workability and strength gain.

As a guide, the rate of addition should be in the range of 500ml to 1.5 litres /100 kg cement for high workability concrete.

Sigmacheme should be contacted for advice where higher dosage are to be used.

Dispensing

The correct quantity of PLAST-337 should be used by means of a dispenser. The measured quantity of PLAST--337 should be added along with the gauging water in the case of batching plants.

Alternatively, correct dosage should be used with about 20% of the total water in the last phase after the mix has been pre wetted.

Overdosing

The overdose of double the recommended dosage can result in increased acceleration of setting time and additional air is entrained which may lead to slight loss in strength.

The ultimate strength of the concrete could be increased if advantage is taken of the increased workability by reducing water.

Packaging

PLAST-S 337 is supplied in 200 Ltrs. And 250 Kgs. containers.

Storage
Shelf life

PLAST-S 337 has a shelf life of 12 months from the date of manufacture provided the temperature is within the range of 2°C to 40°C. If the temperature range is exceeded in any respect, advice should be sought from Sigmacheme. It is recommended that the drums be stored in shade.

Precautions
Health and Safety instructions

PLAST-337 is non-toxic, non-flammable and splashes to the skin should be washed with copious amounts of water. If contact with eyes occurs, wash well with water immediately and seek medical advice.

Typical test results

M400 Mix

Cement L & T OPC : 485 kg/m3, Sand 730 kg/m3

Cement aggregate : 998 kg/m3

Test

Dosage of PLAST-S 337
L/50kg cement

W/C ratio

Slump (mm)

Compressive strength
(N/mm2)

Density
Kg/m3

 

 

 

 

 

3 Days

7 Days

28 Days

 

1

Control

-

0.36

50

28.7

41.3

51.0

2430

2

Workability
Increased

0.4L

0.36

155

30.6

42.3

52.1

2422

3

Strength increased

0.4L

0.32

60

34.0

47.4

56.8

2435