The ready-mixed wet-mixed mortar is used for the tensile bonding test, and the mortar on the specimen quickly falls off. What's the matter?

[Roy]

The compressive strength is the same, and applying on the wall is fine, but only the mortar on most of the test pieces is easy to fall off under the normal maintenance condition, and the 14d will fall off with a slight break. I am still determining the specific reason.

 

[Johnson]

Strength shrinkage may be caused by excessive cement content.

 

[Cassie]

1. Brush the base with a wire brush. Curing in water for one day before forming. During the experiment, take it out and dry it in advance.

2. When forming, oil the frame's inner wall to facilitate demoulding.

3. The demoulding process must be careful; Redo it if the mortar moves relative to the base.

4. For maintenance, the specimen must be wet when the standard requirements are met.

 

[Rony]

It will shrink if the cement content is too high. However, I guess adding too much cement to the wet-mixed mortar is impossible since the cost cannot bear it. It may be that you using too much retarder.

 

[Luis]

Whether the bottom plate is made according to the standard, it should use a rough surface and no oil on it.