Sika® ViscoCrete® SKY 8788

Sika Viscocrete SKY 8788 is a new generation 
superplasticiser with super retention technology. 
It contains polycarboxylate ether polymers and is 
specially formulated for ready-mix concrete 
where slump retention, high strength and 
durability are required in hot climates. The 
excellent dispersion effect makes 
Sika Viscocrete SKY 8788 the ideal admixture 
for the ready-mix concrete industry. The ability to 
work at different water cement ratio and still 
obtain good slump retention allows for the 
manufacture of high quality concrete. 
Sika Viscocrete SKY 8788 is free of chloride and 
also compatible with all cements meeting recognized 
international standards. 
Chemistry and Mechanism of Action 
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. 
Sika Viscocrete SKY 8788 is differentiated from 
conventional superplasticisers in that it is based 
on a unique polycarboxylate 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, 
generates a steric hindrance which stabilizes the 
cement particles capacity to separate and 
disperse. 
This mechanism provides flowable concrete with 
greatly reduced water demand. 
Sika Viscocrete SKY 8788 is not compatible with 
the Sikament series superplasticisers.