CEMWET - AEA

CEMWET - AEA

AIR ENTRAINING, PLASTICIZING & WATERPROOFING COMPOUND

PRODUCT

CEMWET-AEA is a chloride free, short-chain polymeric compound liquid, highly concentrated, homogenous Air entraining agent, having no chemical reaction with cement mortar and concrete. It produces very minute and stable air bubbles that imparts added plasticity and workability to the concrete. CEMWET-AEA has high ability to entrain ainn concrete and a small dose of 0.12 to 0.16% by weight of cement entrains about 5% air which was found to be in the form of extremely small and closely spaced air voids.

APPLICATION:

CEMWET-AEA contributes significant benefits to concrete durability due to its air-entraining, plasticising and water-proofing characteristics and has been recommended for plain and reinforced concrete, mass concrete construction, masonary structures, high­way roads and concrete structures where resistance to frost, freezing & thawing, sulphate attack, drying shrinkage, surface, scaling, crazing, pitting, etc. are required to be improved.

In slip form paving the product provides a high degree of self support to the concrete to give the minimum of edge slump, whilst providing enhanced workability during the placing process.

CEMWET-AEA Should be added either before or during the mixing operation. It is necessary to carry out preliminary site test to determine the amount of air entrained in the fresh concrete. This test can be carried out according to ASTM or DIN 1045 or similar equivalent codes of practice. The volume of air entrained in the fresh concrete should be properly controlled and supervised at construction site and extreme care should be exercised to see that the specified limits are not violated.

CEMWET-AEA is compatible with most of the other admixtures to concrete and this property can be taken advantage of to produce desired results. Especially when high early strength concretes having high resistance against thawing salts are desired as in case of road concretes, a combination of super plasticizer CEMWET-SP-300 with CEMWET-AEA produces excellent results. It can also be used in combination with all CEMWET-SRA, set-retarders and C EM WET- Frost protection aids.

When combining CEMWET-ANTIFREEZE with CEMWET-AEA the admixing operation should be first CEMWET-AEA followed by CEMWET-ANTIFREEZE whereas when a combination of CEMWET-SRA, set retarders with CEMWET-AEA is desired, the retarder should be added prior to addition of CEMWET-AEA, this order of addition will guarantee a good stablization of micropores entrained by CEMWET-AEA. For other desired combinations please refer the mattrer to Technical Advisory Department of ASIAN LABORATORIES, NEW DELHI-20.

ADVANTAGES

IMPROVES WORKABILITY :

CEMWET-AEA improves the workability of concrete and reduces unit water content by 10-12%, while maintaining the slump. Loss of workability due to flaky crushed aggregates is minimised completely and concrete becomes cohesive.

DECREASES SEGREGATION, BLEEDING & PERMEABILITY :

Segregation of aggregates is very much reduced due to increased plasticity. Bleeding of concrete is also decreased.
Permeability of concrete is decreasedsignificantly, reduction in the coefficient ol permeability is to the order of 1 /4 to 1 /5 reduction when tested as per I.S. : 3085-1965.

IMPROVES SURFACE FINISH OF CONCRETE :

Due to improved plasticity in the mix, it is better able to fill all corners and recesses in shuttering. The resultant finish of concrete is very good and less finishing is required when form work is opened.

IMPROVES DURABILITY:

The specimens prepared with Cemwet-AEA, 0.12 to 0.16% by weight of cement and tested as per I.S.: 1126-1957 shows reduction in sulphate attack by 6.0 to 6.2% indicating improvement in the durability of concrete.

The test performed to study the action of freezing and thawing indicates that the resistance of concrete to disintegrating action of freezing and thawing is by more than 80% at 50 cycles.

MAINTAINS STRENGTH OF CONCRETE :

Strength losses are normally associated with air entrainment but concrete made with CEMWET-AEA shows identical results to the control mix, both at 7 and 28 days. The results are as under:


PARTICULARS

Mix 1

Mix 2

Mix 3

ADDITIVE (AEA)

Nona

Normal AEA

CEMWET-AEA

MIX DESIGN :

 

 

 

Aggregates

40-10 mm

40-10 mm

40-10 mm

Sand

Zone 2

Zone 2

Zone 2

A/C ratio

6.0

6.0

6.0

% fines

33.0

33.0

33.0

W/C ratio (Water Reduction, Percent]

0.59 (Nil)

0.56 (5.1)

0.54 (8.5)

PROPERTIES OF PLASTIC CONCRETE :

 

 

 

Slump (mm)

45 mm

40 mm

45 mm

Compaction factor

0.89

0.91

0.93

Ve Be (Sees.)

5.0

3.5

2.0

Air content

1.0

3.9

4.0

PROPERTIES OF HARDENED CONCRETE

 

 

 

Average Compressive strength. 7 days
(N/mm2) 28days


30 1
37.3


28.0
32.5


30.8
37.2

DOSE OF CEMWET-AEA : 0.12 to 0.16% by Wt. of cement.

(i) For 7.5 and 15 cms max. size of aggregate concrete, 2.5 to 3.5% air is adequate.
(ii) for 3.8 cms max. size of aggregate concrete, 4.1% air is optimum.
(iii) for 1.9 cms. max. size of aggregate concrete, 5.0% air is optimum.
(iv)   for mortars, 8 to 10% air is sufficient.

PACKING : Plastic jars/drums of 10. 20 Kg. or steel drums of 220 kg.

NOTE : The benefits likely to be accured with the use of CEMWET-AEA can be appreciated only in a well designed concrete mix which is properly produced and placed. It is important not to exceed entrained air content of 6% in structural concrete, since air content in excess of this will have deterimental effect on strength. Also, it is necessary to measure the volume of air achieved in the concrete.

At all large work sites, it will be economical to have air entrainment meter and the entrained air should be checked periodically to achieve the best results.

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