How to judge whether the workability of dry-mixed mortar is good or not

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How to judge whether the workability of dry-mixed mortar is good or not

The workability of the mortar also refers to the workability or workability of the mortar. It means freshMortarEasy construction operation (mixing, transportation, pouring, vibrating) and can obtain uniform quality, forming compact performance. Workability is a comprehensive technical property, which usually contains three meanings: 1. fluidity; 2. water retention; 3. cohesion. Through these three aspects of physical index values to be reflected.
1. Fluidity (consistency)
It refers to the performance of whether the mortar is easy to flow under its own weight or external force. Its size is expressed in terms of the amount of sinking (or consistency value) (mm). That is, the number of millimeters at which the cone of the mortar consistency tester sinks into the depth of the mortar.
2. Water retention
The ability of fresh mortar to preserve moisture is called water retention. It also refers to the nature that the constituent materials in the mortar are not easy to separate. Water retention is usually expressed by delamination degree (mm). The evenly mixed mortar is first measured for its sinking amount, and then the stratification tester is installed. After standing for 30 minutes, the bottom 1/3 mortar is taken and then the sinking amount is measured. The difference between the two sinking amounts is called the stratification degree.
3. Adhesion
There is a certain cohesion between the constituent materials of fresh concrete, and the performance of delamination and segregation will not occur during the construction process. Cohesiveness reflects the uniformity of concrete mixture. If the cohesion of concrete mixture is not good, the aggregate and cement slurry in concrete are easy to separate, resulting in uneven concrete, and honeycomb and cavity will appear after vibration. The main influencing factor is the ratio of mortar.
The workability of concrete mixture is a comprehensive concept, it is difficult to use a simple evaluation method to fully and properly express, usually using the slump test to determine the fluidity of concrete mixture, supplemented by intuitive experience to assess the cohesion and water retention to comprehensive assessment.

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