The open time of wet-mixed mortar and its solutions
1. The opening time refers to the usable time of the mortar (the period from the production of the mortar to the beginning of the loss of workability).
2. The construction performance and strength of the mortar used during the opening hours will not change. After the opening time, the workability of the mortar deteriorates, and a lot of water must be added and stirred again to barely construct. At this time, the mortar will have many plastic cracks on the wall and the strength will also deteriorate.
3. If the opening time is too short, the construction site mortar will lose construction performance or even harden before it is used up, causing waste.
4. Admixture is the main admixture to adjust the opening time of mortar. The more admixtures, the longer the open time of the mortar. Under normal circumstances, most construction sites close at 18:00. The opening time of the mortar should be adjusted to 20 o'clock in the afternoon (the opening time of the actual construction site is 6 to 10 hours shorter than the setting time of the mortar, depending on the actual temperature and humidity of the construction site) to meet the requirements of most construction sites. If there are special requirements on the site, the amount of admixtures should be adjusted accordingly.
5. When the temperature is high, the amount of admixture in the mortar should be increased accordingly; when the temperature is low, the amount of admixture in the mortar should be reduced accordingly (the technical department will give different formula tables according to different seasons).
6. Different varieties or brands of cement will also affect the opening hours. When using different grades of cement, mortar trial matching experiments are required.