What benefits can water reducers bring to self-leveling compounds?
Water reducers in self-leveling compounds
Water reducers are an essential component of self-leveling compounds to improve the fluidity of the mortar. Polycarboxylic acid water reducers are commonly used, which can quickly adsorb onto the surface of cement particles and disperse them through electrostatic repulsion and steric hindrance. They have the characteristic of rapid dispersion, which can greatly shorten the time from adding water to maximizing the fluidity of the mortar.
1.Improve the stability of pumped mortar
Compared with traditional manual mixing of mortar, continuous mechanised pumping construction can effectively improve the construction efficiency of large-scale sites. However, the mixing time of this type of special mortar pump is relatively short, which is not enough to allow traditional self-leveling mortars sufficient time to ‘mature’. Therefore, self-leveling mortars need to rely on the rapid dispersing properties of water reducing agents to shorten the time for the mortar to fully mix and react with water, in order to stabilise the fluidity of the mortar and the quality of the product.
2.Improve pumping efficiency
Shortening the time it takes for the mortar to reach its maximum liquefaction point is the key to improving pumping efficiency. Shortening the liquefaction time can be achieved in a number of ways, such as improving mixing efficiency, increasing mixing water, and using high-efficiency water-reducing agents.
However, at the rated mixing power, increasing the mixing water will greatly reduce the performance of the mortar in all aspects. Adding water-reducing agents can effectively improve the speed at which the mortar is wetted and dispersed by water, greatly reducing the mixing time. This quickly disperses the cement mortar and stabilises its rheological state, reducing the occurrence of some problems and improving the conveying efficiency of the mortar pump.
3.Improve the workability of the mortar
Large-area self-leveling mechanised construction places higher demands on the workability of the mortar. Water-reducing agents can effectively shorten the mixing time of the mortar, making it easier to control rapid and continuous pumping construction. Their main effects can be summarised as follows:
(1) They can quickly disperse cement mortar at a low water-cement ratio, opening up the cement to a flocculent state;
(2) It can reduce the power consumption and wear of the mixing paddle, quickly complete the mixing process, and there is no problem of delayed fluidity;
(3) It can reduce the water demand of the self-leveling floor and increase the density of the mortar, thereby effectively improving the strength of the mortar;
(4) It dissolves quickly, reducing surface defects caused by undispersed aggregates;
(5) It can quickly disperse and take effect at both high and low temperatures.
