The main properties of mortar include apparent density, compressive strength, consistency, water retention, pumpability, shrinkage, setting time and tensile bond strength. These performance indicators are crucial to evaluating the quality and application effect of mortar.
Apparent density: It shows the density and viscosity of mortar. The test method is to fill a 1L density container with mortar, and measure its weight as the apparent density value.
Compressive strength: It shows the hardness of mortar. The test method is to pour the mortar into a standard mold, and perform a compression test after curing to the specified age. The result is expressed as the compressive strength of the cube.
Consistency: It shows the dryness and thinness of mortar. The test method is to fill the cone bucket with mortar, and measure the depth of the test cone falling into the mortar as the consistency value.
Water retention: It shows the ability of mortar to retain moisture. The test method is to fill the round test mold with mortar, cover the mortar with filter paper, and measure the proportion of water absorbed by the filter paper to the total water content of the mortar.
Pumpability: Very important for mechanized construction. The test methods include extrusion method and static method, which are judged by observing the fluidity and water retention of mortar.
Shrinkage rate: It shows the volume stability of mortar after hardening. The test method is to put the mortar into the shrinkage test mold and measure the shrinkage length after 28 days.
Setting time: It shows the time from adding water to stirring to hardening of mortar. The test method is to put the mortar into the setting time test mold and record the time required for the test needle to press into the mortar.
Tensile bond strength: It shows the ability of mortar to adhere to the base surface after hardening. The test method is to bond the mortar to the base surface and test the force required to pull it off after 28 days.
These performance indicators are measured by different test methods to help evaluate the quality and applicability of mortar.
