Analysis on the Causes of the Hollow Drum of Granite Stone

Analysis on the Causes of the Hollow Drum of Granite Stone

What is a stone hollow drum?

Empty drum is a common quality problem in housing engineering. It means that the decoration surface (plastered layer or tile) and the base layer are not handled well, and the combination is not tight, resulting in a void space between the base layer and the decoration surface. Use hard objects lightly When you hit it, you will hear a sound like a drum, which is called "empty drum" in engineering. After the granite floor is paved, there are different degrees of hollowing. The hollowing is the use of quality inspection tools to hammer across the surface of the stone, or lightly tap the surface of the stone to hear the sound of a drum, which is obviously different from the sound of a firm paving. The sound of light scratching or tapping on the stone surface mainly exists in the corners of the granite stone surface layer, and very few exist in the middle of the stone surface layer. The reasons for granite hollowing are analyzed as follows:

1. Raw materials

If the sand is too fine and the specific surface area is large, it will increase the cementitious material and the water consumption per unit, which will reduce the strength of the mortar, increase the shrinkage rate, and easily produce shrinkage cracks, resulting in cracks and voids between the granite surface layer and the bonding layer. drum. The selection of cement also has a certain impact on the formation of hollow drum. It is recommended to use ordinary Portland cement and Portland slag cement with no less than 32.5 grade, and special cement is not recommended. Otherwise, the bonding performance of special cement and granite stone should be tested and determined. The water used for mixing cement mortar and plain cement slurry contains alkali or acidic substances, which easily reacts with the cement, which affects the bonding strength of the mortar and makes the granite floor hollow.

2. Operational technology

The base layer is not cleaned, not sprinkled and wetted, not brushed with the cement slurry bonding layer, the dry hard mortar is too wet or too dry, the dry hard mortar is not brushed with the cement slurry bonding layer on the upper part, and the stone is not soaked in water. The cause of hollow granite floor. Therefore, the preliminary work needs to be handled well during the laying process. The general process standard does not specify specific requirements for the number of hammers used to hit the granite with a rubber hammer when paving the stone. The author found that the granite floor with more hammers is generally less empty than the granite floor with fewer hammers. The drum phenomenon is relatively rare. Therefore, insufficient requirements for the number of hammers are also an important reason for hollowing.

3. Maintenance

The granite floor was not cured in accordance with the specifications, which caused the cement mortar to shrink and crack due to the lack of moisture during the setting and hardening process, which caused the granite floor to hollow.

4. Protection of finished products

The finished granite floor is not protected by the finished product, and people and equipment will vibrate and load in the early morning, so that the cement mortar that is not completely cured and hardened is not firmly bonded to the granite surface, resulting in hollowing.

5. No strict jointing treatment

makes the ground during use due to rainwater seeping from the joints, resulting in loss of strength of the cement mortar, resulting in hollow granite floor.

The empty drum not only affects the use function of the floor, but also causes the floor to bulge, the surface layer falls off, and breaks over time. The use requirements can be met through rework, but rework and repair will have certain adverse effects on the construction unit and construction unit. It should be strictly controlled during construction, and the quality should be firmly controlled to avoid rework and repair. Therefore, in the process of laying granite, it is still necessary to pay attention to the above aspects to reduce the occurrence of hollowing and increase the service life of granite.