Many stone materials are still in good condition when they come out of the factory after placing an order, but after the on-site construction and paving, there are large areas of damage, cracks and other phenomena. Why is this?
This article is about the prevention of stone cracking.
It will be expanded from the following two aspects:
1. Hazard caused by cracking
2. Cause analysis and prevention of phenomenon
1. Hazard caused by cracking
1. Dark crack → open crack → fracture → broken
Many stones, such as Shaanna Beige, can cause a large number of dark cracks, even if they are not broken, if they are not paved correctly. Dark fissures become bright fissures, and open fission fractures will eventually cause the stone to be broken, and the problem will become more and more serious.
Shaanna beige with obvious cracks△
2. Follow-up questions
（1) Back water, hide dirt and grime
The open cracks and dark cracks of the stone will cause back water and form a large number of black seams, causing serious visual and sensory problems.
（2) Back to alkali
Cracks can form channels in the bottom and surface layers of the stone. The water on the surface will seep down, and the alkaline substances in the bottom cement will be precipitated upwards, resulting in the phenomenon of returning to alkali, which is extremely difficult to cure.
2. Causes and Prevention
1. The natural defects of the stone itself
Granite paving is not prone to problems, and most of the problems are marble: there are generally many natural defects, such as cracks, sand holes, looseness, and inclusions.
If it is directly laid on the ground without repairing and filling operations in advance, once it is wet and polluted, lesions and damages will first occur in the defective parts and thus expand.
Spanish Beige (Old Mine)△
dark crack representative
Gold thread beige △
Silver thread beige△
Santa Ana beige △
The higher-grade marble is more prone to breakage and cracking: precious stones such as Saanna beige, Spanish beige, New West beige, golden line beige, silver line beige and other precious stones are most likely to crack during the paving process, so the installation process requires Take special care to protect it and do not install it violently.
1) In the selection of ground marble materials, we must give correct opinions to Party A according to the characteristics of the stone, such as wood grain stone and other soft stone materials, such as golden century beige and other stone with more cracks, it is not suitable Selected as ground stone.
2) Before laying the stone, the board surface should be inspected, and the stone with hidden cracks, inclusions and other hidden quality problems should be removed.
3) In the construction of large-scale ground stone, it is best to leave a natural joint of 1~2mm between the plates, and do not completely close the joint to prevent the stone from bulging and cracking due to temperature difference and internal water pressure in the stone in the future.
2. The ground structure does not meet the paving conditions
（1) Before paving marble, understand the structure of the ground, observe whether the structure is a steel body, and whether the cushion is hollow and cracked.
（2) When laying stone on the expansion joints and settlement joints of the building, you must choose the corresponding method according to the atlas. The disconnected construction must be disconnected for construction, and it is not advisable to lay it directly.
Stone paving floor layering:
（1) Bottom layer: leveling layer
Mix cement and large sand in a ratio of 1:2, add water to semi-dry, the standard is to knead by hand and not form a group, it will be loose and spread evenly on the ground.
（2) Intermediate layer: adhesive layer
①Cement fixing method: add water to the cement, make it thinner, and brush it on the back of the stone. Relying on the adhesion and reverse osmosis of cement, it is bonded with the cement mortar on the bottom layer to fix the stone.
②Adhesive fixation method: Use special stone adhesive or marble glue to bond and fix the stone.
（3) Top layer: Stone
Paint the stone with cement or adhesive, and tap with a rubber hammer to fix it.
3. External force damage and improper construction
1) Tap too hard
When workers lay stone, many times in order to improve efficiency, when they hit with a rubber hammer, the force is too strong, and the stone is shattered. A rubber mallet that is too large will also break the stone.
In addition, many installers’ skills are currently limited to ceramic tiles and artificial marble. These materials are artificial synthetic stones, which are stronger than natural marble. Even if they are knocked hard, they are not easily broken and broken. However, once they encounter natural marble paving, if paving is still used The strength and manipulation of ceramic tiles or artificial stones are most likely to cause stone breakage and fracture.
（2) Hit with a hammer handle, hammer, etc.
Hammer handle (including sticks, bricks) or hammer strikes, the force point is small, the pressure is strong, no shock absorption, it is easy to cause stone breakage.
（3) Rolling of heavy objects on the construction site
Two indicators of stone: compressive strength and bending strength, beyond this pressure, the stone will be broken.
Therefore, the rolling of machinery and heavy objects on the construction site will also cause large-scale crushing of the stone.
1) When paving the stone, it is necessary to use a rubber hammer to hit the stone with a suitable force, lightly and more, and scattered.
2) During the construction period, the marble floor will crack due to the pressure exceeding the load. Therefore, when the project is in the completion stage to write the instructions for use, it should be explained.
If there is a problem with stone decoration, both internal and external factors will affect it. As a project builder, what we need to do is to try our best to avoid problems and make stone decoration more perfect.
You can try when paving fragile marble, you should first find a granite slab of the same size, put it on the leveling layer paved with cement mortar, tap and level it. Then paint the back of the marble slab with grout, tap it lightly, and fix it.
This can prevent more than 95% of the marble from being broken and cracked due to paving.