What is a hollow stone drum?
Empty drum is a common quality problem in housing engineering. It means that the decoration surface (plastered layer or facing brick) is not handled well with the base layer, 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 paving, there are different degrees of hollowing. The hollowing is the use of quality inspection tools to hammer across the stone surface, or lightly tap the stone surface to hear a drum sound, which is obviously different from the firm paving. The sound of light scratching or tapping on the surface of the stone 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. In terms of 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 alone, 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 drums. It is recommended to use ordinary Portland cement and Portland slag cement with a grade of not less than 32.5, 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 chemically reacts with cement, which affects the bonding strength of the mortar and makes the granite floor hollow.
2. Operation process
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 wetted with water, etc., are all construction techniques. The cause of hollow granite floor. Therefore, the preliminary work needs to be handled well during the laying process. The ordinary craft standard does not make specific requirements for the number of hammers used to hit the granite with a rubber hammer when paving the stone. The drum phenomenon is relatively rare. Therefore, insufficient requirements for the number of hammers are also an important reason for hollow drums.
3. Maintenance
The granite floor is not cured in accordance with the requirements of the specification, so that the cement mortar shrinks and cracks due to the lack of water during the setting and hardening process, which causes the granite floor to hollow out.
4. Finished product protection
The finished granite floor is not protected by the finished product, and people, equipment, etc. generate vibration and loads in the early morning, which makes the cement mortar that is not completely hardened and hardened and the granite surface layer bond not firmly, resulting in hollowing.
5. No strict jointing treatment
As a result, rainwater infiltrates from the joints during the use of the ground, resulting in loss of strength of the cement mortar and hollowing of the granite ground.
The hollow drum not only affects the use function of the floor, but also causes the floor to bulge, the surface layer falls off, and breaks after a long 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, we still need to pay attention to the above aspects to reduce the occurrence of hollowing and increase the service life of granite.
