Stone back reinforcement refers to adding reinforcement into the groove on the back of marble, which is a method to strengthen marble and avoid marble fracture. After the stone is cut into plates, it is very thin and easy to break. In order to increase the strength of the stone, try to ensure that the stone does not break during processing, transportation, and installation, so as not to affect the overall aesthetic feeling.
The stone back reinforcement is actually a kind of “planting reinforcement” technology. “planting reinforcement” technology refers to drilling holes in the original concrete structure, injecting structural glue, and rotating new reinforcement into the hole. This technology is widely used in design changes, reinforcement, and change projects such as adding beams, columns, cantilever beams, and slabs.
What are the materials of stone backing?
The materials of stone backing bars include iron, galvanized, stainless steel, copper, aluminum alloy, and fiber. They have their own characteristics in strengthening marble. The most ideal reinforcement material is stainless steel bar, which will not rust, and has high reinforcement strength but a high cost.
The plastic rod is a flexible material, and the reinforcement strength is not enough when strengthening some large-sized stone materials, slender stone materials, and heavy stone materials. In these cases, the plastic rod cannot be used for reinforcement.
Considering the factors of cost and reinforcement strength, general stone enterprises choose steel bars as stone back bars.
However, everything has its advantages and disadvantages. Although adding steel bars to marble can play a role of reinforcement and protection, it may cause a stone disease, which is also a very difficult stone disease to be treated, that is, steel bar rust. It is difficult to deal with the problem of steel bar rust back, which has brought adverse effects on the stone industry.
Why is the rebar rusted?
1. Iron reinforcing bars are corroded by water during stone processing, gradually oxidized and rusted, and then migrate to the surface of the stone through the pores of the stone to form regular rust spots.
2. After the stone is installed, the back reinforcement strip will be oxidized and rusted after being eroded by the acid water vapor of the cement in the stone base, and will migrate to the stone surface to form yellow rust spots.
Rust caused by iron stone backing bars cannot be completely treated. Since the pollution source is inside the stone, the stone is eroded by acid substances and water vapor in the base course after installation. With the rising of water vapor, pollutants continue to migrate to the stone surface to form stubborn rust spots. Even if some rust stains on the stone surface are temporarily restored with rust removal products, there is still a possibility that the rusty back bars of the pollution source will continue to rust.
Rust spots caused by iron stone back ribs can not be completely eradicated, so it is necessary to strictly control the installation process and correct material selection when the stone is embedded with reinforcing bars. In order to avoid adverse effects on the stone industry, iron backing bars, especially light-colored marble, shall not be used as far as possible. What are the technical requirements for marble back reinforcement?
01. Requirements for plate thickness
Generally, the diameter of reinforcement for marble slab reinforcement is 6mm, and the groove depth for reinforcement is 8mm. If the distance between the 20mm thick engineering slab rebar and the stone surface is 11 mm~12 mm, even if the rebar embedded in the stone is rusted, the possibility that the rust will rise 12mm and penetrate the stone surface is extremely small.
However, the thickness of the large slab is now from 20mm to 15mm, and even thinner. The distance from the rebar to the stone surface calculated by the 15mm thick slab is only 7mm, or even less than 7mm. The rebar is rusty, and the rust can easily rise to the stone surface with the help of the water in the stone. This is a very important reason for the rust of steel bars used as backing bars, which leads to stone surface lesions. For marble reinforced with steel bars as backing bars, the distance between the steel bars and the stone surface should be more than 10mm. Once the steel bars are rusted, the rust will not easily rise to the stone surface.
02. Requirements for rust and oil removal of reinforcement
The rebar is very easy to rust. It will rust quickly when placed in a damp environment. Therefore, the marble must carefully remove rust when using rebar as the back reinforcement, so that the rebar surface is free of rust.
03. Requirements for cleaning and drying in the reinforcement trough
The drying in the rebar groove can prevent the rebar from rusting in the stone, but many stone processing enterprises will not strictly implement this process requirement. As soon as the reinforcement groove is opened, use the air pipe to blow the water in the groove, and add reinforcement when there is no water on the groove surface. In this case, steel bars are added. After the water vapor in the stone is sealed with glue, the steel bars will rust under the long-term effect of water vapor. If the stone is very thin, the rust will easily rise to the surface of the stone, causing yellowing of the stone.
04. Glue and modulation requirements
The reinforcement shall be reinforced with special glue, and glue shall be prepared strictly in proportion. After reinforcement with adhesive, the adhesive and reinforcement shall be firmly combined. Some rebar and glue are not tightly and firmly combined. When the rebar is pulled hard, the rebar and glue are separated, and the glue does not wrap the rebar at all. The water passes through the glue, causing the rebar to rust.
05. Quality requirements for glue repair of a large plate
For marble with many cracks on the surface, the large slab must be repaired. If the surface cracks are not repaired properly, the steel bars will rust after the stone is added to the steel bars, because the water will enter into the stone through the cracks on the stone surface, which will rust the steel bars and cause stone lesions.
06. The marble that is prone to yellowing does not use reinforcement as back reinforcement
Some marbles that are prone to yellowing should not use steel bars as backing bars, such as white crystal, Baoxing white, elegant white, snowflake white, Karala white, and other similar stones. These stones are prone to yellowing even if they are not reinforced. Adding reinforcement may speed up yellowing and increase the severity of yellowing. These stones are expensive, and it is better to add stainless steel bars.
07. Attach importance to the stone surface protection process
Now there is no marble product that is not waterproof. If the waterproofing is good, the marble product that is reinforced with steel bars should not have water inside the stone, and the steel bars will not rust. We should attach great importance to the waterproofing of stone products to ensure the waterproof effect. In order to save cost, do not use an inferior waterproof agent for protection, which may cause rust or reinforcement. Because the lesion caused by the rust of the back rib of marble cannot be cured.
08. Construction requirements
1. The stone specification plate shall be cut as little as possible and not cut on site; The stone cut on site shall be protected again;
2. Stone jointing is not good, the construction is hollow, and water enters into the stone through the gap between the stones, causing stone lesions. The pointing of stone products seems to be a very small thing, but it has a great impact on the final effect of stone. Carefully follow the process, specification, and standard, and do it carefully to ensure that the back rib stone will not be diseased.
