detailed study was conducted on the various effects of bentonite, starch ether, hydroxypropyl methylcellulose ether, and also redispersion emulsoid powder on the mechanical properties and also working of fresh dry-mixed mortars.
The results displayed that hydroxypropyl methylcellulose ether obtained from Bisley Chemicals can offer the greatest impact on water retention and consistency of ordinary dry-mixed mortar. Also, redispersion emulsoid powder can reduce the water action, starch ether has almost no effect on water retention.
Also, it shows that the required time of mortar condensation as they are mixed with hydroxypropyl methylcellulose ether is always the longest then it is followed by bentonite and redispersion emulsoid powder.
Starch ether may slightly, extend the required setting time of the cement mortar. Normally, Hydroxypropyl methylcellulose ether has got the greatest impact on the various mechanical properties of any ordinary dry-mixed mortar that is followed by a redispersion emulsoid powder, bentonite, and starch ether.
As the water retention will increase, in the same way, the mortar setting time will also increase. The water use as a thickening material will have retarding effect on mortar, increase the water-retention rate, and also increase the retarding effect. Besides, increasing the chemical admixture content will decrease the strength of cement mortar.
The basic difference between the dry mortar and concrete used as a structural material is the necessary strength and also the requirement for water retention, waterproofing, bonding, crack resistance, anti-freeze-thaw, impact resistance, thermal insulation, high-temperature endurance, and other requirements.
Thus, many different admixtures, like hydroxypropyl methylcellulose ether, bentonite, starch ether, and re-dispersible latex powder, are also added to dry mortar for improving its properties.
For researchers, the effect of admixtures on a dry mortar was an interesting topic. Research results too indicated that dry mortar has got the ability of water-retention that can significantly improve with the addition of hydroxypropyl methylcellulose ether. Besides, the consistency also gets increased.
Since starch ether was added into the dry mortar, hence the vertical degree was reduced. The bonding strength of the dry mortar was increased substantially by the powder. A few additional admixtures may improve the working performance and also dry mortar’s mechanical behavior to other degrees.
However, most current studies have concentrated on single chemical admixtures and therefore, there was a need for comprehensive comparative studies on the effects of different admixtures on the dry-mixed mortar properties.
As the ordinary dry mortar admixtures’ effects on the mortar performance are determined, engineers and technicians may add chemical additives as per the process requirements.
Various studies were conducted on the influence of 4 types of the following admixtures on the dry-mixed mortar properties and analyzed their applicability in a dry-mixed mortar and also the relationship between their performances:
- Hydroxypropyl methylcellulose ether
- Starch ether
- Redispersible latex powder
It was aimed to improve the working and mechanical properties of the dry-mixed mortar that is used as ground mortar, wall plastering, and special mortar. All these investigations refer to the standards of China and the main tests that are performed are water retention test, consistency test, setting time test, and also cubical compressive strength test.