Rofluid H is a new generation admixture, which is a yellow to brown aqueous solution of polycarboxylate ether (PCE) with low viscosity. PCEs are compounds with a specific, so-called comb structure, which consists of a long main chain and side chains with lengths resulting from the number of repeating units of ethylene oxide and / or propylene. The product is used as a high-performance batched water reducer in the production of concrete. It is also fully compatible with other products of the Rofluid line.
The mechanism of action of Rofluid H results from its chemical structure. Polymer chains, adsorbing on the surface of cement grains, create a steric hindrance for neighbouring grains. The resulting particles with a specific hydrodynamic volume (different depending on the structure of the polymer) will repel each other when they are too close together. Agglomeration of cement grains is then difficult, which in turn extends the time it takes to produce its hydration products and delays the setting of the concrete mix. In addition, water trapped in cement agglomerates is released, which leads to less consumption of batched water. The addition of Rofluid H also allows for very good workability of the mix, while preventing segregation of ingredients and creating uniform concrete.
A small addition of Rofluid H reduces the water / cement ratio, reducing batched water consumption by up to 35%. This has a direct impact on the durability of concrete, increasing its early strength (which allows faster demoulding of concrete elements) and late strength. Concrete tightness is also improved, i.e. its resistance to aggressive substances and frost, as well as resistance to abrasion.
It should be remembered that the amount of PCE added to the concrete mix depends, among others on the type of cement, the method of preparing the mix, the method of mixing or ambient temperature. To obtain concrete with standard strength it is recommended to use 0.4-1.0% Rofluid H in relation to the weight of the binder, while for obtaining high-strength concrete with high fluidity, the admixture addition should be slightly higher, 0.5-1.5% product to the cement binder mass. Rofluid H does not inhibit cement hydration at low temperatures, so it can be used at an air temperature of -5 ° C without compromising the consistency of the concrete mix.
The use of Rofluid H is recommended primarily in the production of self-compacting concrete (SCC), large-size concrete elements with the required high strength and high workability, bridge concrete, but also precast concrete. It is particularly recommended as an efficient batched water reducer. The concrete mix after applying Rofluid H will have a very good consistency, extended setting time, and the resulting concrete will be more durable and tight.