In the high concentration gas environment for a long time, it will cause skin and mucous membrane damage, poison the central nervous system, cause visceral dysfunction to poisoning, and have potential carcinogenic effect.

Therefore, precast building sealant is a very important waterproof material in precast buildings.

The sealant has excellent elasticity, good weather resistance and excellent aging resistance; But the surface finish is poor.

If the material is improperly selected, it will affect the sealing performance and service life of cast buildings, resulting in sealant cracking, water leakage, serious and even sealant failure shortly after assembly, affecting the safety of buildings.

Environmental protection green environmental protection is the demand of economic and social development; PU glue contains a certain amount of free isocyanate, which is harmful to people.

The mechanical properties of sealant for precast construction shall include displacement capacity, elastic recovery rate, tensile modulus, elongation at break and other indicators.

The content is the author’s personal view, and does not represent the official account.

The performance of precast building sealant requires that the exterior wall panel of precast building is located on the building facade and directly in the atmospheric environment, including temperature, humidity, building load, seismic load, sunlight and other factors will affect its performance.

Silicone sealant silicone sealant (SR) is a sealant prepared with polydimethoxysiloxane as the main raw material.

Therefore, it is required that the sealant for precast building should also have various requirements and strong comprehensive performance, The main performance requirements are as follows: mechanical properties: under the action of load and temperature, the precast exterior wall panels will produce relative displacement between the exterior wall panels.

Bubbles and cracks may occur when it is used in a high-temperature and thermal environment.

Once the sealing failure leads to leakage, it will not only affect the appearance and quality of precast buildings, but also seriously affect the residence and use of users.

Moreover, the storage stability of one-component glue is greatly affected by the outside world.

For cast building joints that do not need to be painted, silicone sealant can be used, which can give full play to its aging resistance and have a long service life.

It belongs to an environment-friendly curing system.

Some people feel dizzy, headache, nausea and shortness of breath.

It is proposed that by 2025, the proportion of new precast buildings will reach more than 30%.

Cultivate a number of precast construction production bases, establish a professional, large-scale and digital production system based on standard parts, promote the formation of a complete industrial chain and improve the level of construction industrialization.

Polyurethane sealant polyurethane sealant is mainly composed of polyurethane prepolymer, which has high tensile strength and excellent elasticity; However, it has poor weather resistance, alkali resistance and water resistance, and can not be heat-resistant for a long time.

Silane modified polyether adhesive has the advantages and advantages of silicone sealant and polyurethane sealant.

The molecular structure of sealant determines its performance, and the performance of sealant with different structure is very different.

It is necessary to inject special sealant to play a waterproof role.

After curing, the main structure remains unchanged and still retains the excellent performance of the original structure, but the way of curing and crosslinking is changed.

If there is any infringement, please let us know.

In the whole curing process of silane modified sealant, only small molecules of alcohols are released, which will not cause harm to human body.

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At the press conference of the State Council on February 24.

The performance of sealant will directly affect the waterproof effect of precast buildings.

After long-term use, there is a risk of cracking and water leakage due to its own aging.

Weather resistance # jgj1-2014 technical specification for cast concrete structures expressly stipulates that the waterproof sealing material for building joints should be weather resistant material.

It is mostly used in glue joints not exposed to sunlight (internal joint sealing of buildings).

Sealant is an important supporting material for precast buildings.

Wang Menghui, Minister of housing and urban rural development, said that precast buildings will be vigorously developed this year.

The main chain of polyurethane glue contains a large number of C-N bonds, and its bond energy is the lowest compared with silicone glue and modified polyether glue.

It is not for commercial purposes.

More information is welcome to add customer service to AMI adhesive exchange group.

Even very few people vomit blood immediately after smelling this smell, and in serious cases, they will faint immediately; It can accumulate in the human body.

The official account has the final power to interpret the statement..

It is the first choice of precast building joint sealant.

Magnetic Thread Disc

It shows high displacement resistance, good finishing, adhesion, environmental friendliness, excellent pollution resistance, constructability and good aging resistance.

We will look for the mystery of the world from the professional point of view.

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When using, pay attention to keep good ventilation and take necessary protective measures.

Under long-term sunlight, the C-N bond in the molecular chain of polyurethane adhesive is easy to break, pulverize and crack, which is also the main reason why the weather resistance of polyurethane adhesive is not as good as silicone adhesive and modified polyether adhesive.

according to different chemical compositions.

Silane modified polyether adhesive silane modified sealant modifies the silane functional group to the end of a specific polymer.

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Therefore, the sealant for precast construction must have certain elasticity, certain free expansion and deformation capacity, and excellent recovery energy.

In the process of implementing the precast building, due to the assembly mode of the precast building, there are many joints in the outer wall of the building, which seriously affects the sealing effect.

Moreover, the subsequent maintenance cost may be several times that of the initial sealing rubber material and construction cost.

Classification of precast building sealants common in the market can be divided into polyurethane (PU), silicone (SR), silane modified polyether (MS), etc.

It is very suitable for joint sealing of cement precast components in precast buildings.