Chemistry and mechanism of action of GLENIUM 51
Conventional superplasticisers , such as those based on sulphonated melamine and naphthalene formaldehyde condensates, at the time of mixing, become absorbed onto the surface of the cement particles. This absorption takes place at a very early stage in the hydration process. The sulphonic groups of the polymer chains increase the negative charge on the surface of the cement particle and dispersion of the cement occurs by electrostatic repulsion.
GLENIUM 51 is differentiated from conventional superplasticisers in that it is based on a unique carboxylic ether polymer with long lateral chains. This greatly improves cement dispersion. At the start of the mixing process the same electrostatic dispersion occurs as described previously but the presence of the lateral chains , linked to the polymer backbone, generate a steric hindrance which stabilises the cement particles capacity to separate and disperse.
This mechanism provides flowable concrete with greatly reduced water demand.
Typical applications
The excellent dispersion properties of GLENIUM 51 make it the ideal admixture for precast and readymixed concrete where low water cement ratios are required. This property allows the production of very high early and high ultimate strength concrete with minimal voids and therefore optimum density. Due to the strength development characteristics the elimination or reduction of steam curing in precast works may be considered as an economical option.
GLENIUM 51 can be used to produce very high early strength floor screeds. For screed mix designs consult BASF Technical Services.
- high workability without segregation or bleeding
- less vibration required
- can be placed and compacted in congested reinforcement
- reduced labour requirement
- improved surface finish
Packaging
GLENIUM 51 is available in 208 litre drums and in bulk tanks upon request.
Effect on hardened concrete properties
- increased early and ultimate compressive strengths
- increased flexural strength
- higher E modulus
- improved adhesion to reinforcing and stressing steel
- better resistance to carbonation
- lower permeability
- better resistance to aggressive atmospheric conditions
- reduced shrinkage and creep
- increased durability
Compatibility of GLENIUM 51
GLENIUM 51 must not be used in conjunction with any other admixture unless prior approval is received form BASF Middle East Technical Services.
GLENIUM 51 is suitable for mixes containing:
- microsilica
- pulverised fuel ash
- ground granulated blast furnace slag cement
Dosage
The normal dosage for GLENIUM 51 is between 0.5 and 0.8 litres per 100 kg of cement ( cementitious material ).
Dosages outside this range are permissible subject to trial mixes.
Typical properties*
| Form |
viscous liquid |
| Colour |
light brown |
| Relative density |
1.1 @ 20°C |
| pH |
6.6 |
| Viscosity |
128 +/ - 30 cps @ 20°C |
| Transport |
Not classified as dangerous |
| Labelling |
No hazard label required |