China according to its own climatic characteristics of the construction of the wall heat transfer coefficient limit value regulations, that is, according to the actual climate characteristics of each region to consider the heat transfer coefficient of the wall structure, but also to take into account the impact of solar radiation on the energy consumption caused by the building. Therefore, different performance wall materials should be selected for building construction in different regions, and the heat insulation and thermal insulation performance of the materials must be adapted to the local climatic characteristics.
And the reinforced concrete structure is now adopted by a wide range of construction projects because of its material specificity, structural feasibility, flexibility of layout and various advantages such as stiffness and ductility.
1, China’s wall insulation technology common problems summarized
China’s wall insulation technology has more application advantages, can effectively protect the wall temperature, so that the wall from the serious impact of external low temperature, can effectively extend the service life of the building structure, but also to prevent the emergence of thermal bridges, is the temperature stress as much as possible to reduce, but also to reduce the excessive occupation of the building area. However, China’s exterior wall insulation technology in the actual application, there are certain drawbacks, first of all, there is a fire hazard, many buildings using insulation materials are flammable materials, it is easy in the case of open fire, causing a widespread fire.
Secondly, is the need to withstand the wind pressure is larger, because the floor is higher, the more the wind will bear, coupled with the impact of negative pressure, it is easy to make the insulation board appears to fall off the problem. Finally, some areas of its own humidity is larger, which will make the building indoor humidity is also larger, in the case of water vapor infiltration, it will make the building wall structure and insulation layer between the formation of separation off the situation, seriously affect the effect of building engineering exterior wall insulation.
Because of our common wall insulation technology has these defects, so our country’s relevant personnel began to apply a new type of external wall insulation technology, the technology is reinforced concrete wall insulation construction technology, the application of this construction technology, to a certain extent, to solve the problems of the application of common wall insulation technology, so that the external wall insulation effect of the construction project has been effectively guaranteed.
2, reinforced concrete wall insulation construction requirements
2.1 The selected material requirements
First of all, the requirements of the polymer selected to do the insulation layer, the conventional reinforced concrete wall insulation construction of polymer materials selected mostly the following three kinds: the first is a powder material, the second is composed of part of the powder and liquid colloid, the third is composed of quartz sand, the three can be mixed in proportion to the fusion. Secondly, the choice of netting woven fabric.
Usually in the construction of reinforced concrete wall exterior insulation selected mesh braid, is made of waterproof polymer and alkali-resistant fiber woven mixture, it has the effect of enhancing the strength of the wall exterior insulation and enhance its crack resistance. Finally, the choice of anchorages, in the construction of reinforced concrete wall insulation, anchorages are used to fix the insulation board for splicing, often selected plastic nails and metal nails with anti-corrosion coating.
2.2 reinforced concrete wall insulation construction construction requirements
First, out of the consideration of the factors of cracks generated after the construction of reinforced concrete wall exterior insulation, construction operations should be carried out when the temperature is greater than or equal to 5 ℃; wind outside the wall is less than or equal to 5 levels of the premise. To avoid the construction operation wall surface temperature is too high, cut try to avoid the rainy season construction.
Second, before the construction of reinforced concrete wall insulation must ensure that the building’s fire protection system, various pipelines, the wall must be a variety of buried parts, doors / windows are to construction is completed and inspected.
Third, the reinforced concrete wall insulation construction of the base wall requirements, must ensure that its surface is smooth, no convex and concave; to ensure that its adhesion with the leveling layer firmly without “delamination” phenomenon and “drum” phenomenon; at the same time, the base wall wall humidity should be up to standard, too dry or too wet will Affect the construction of reinforced concrete wall insulation.
3, reinforced concrete wall insulation of the specific construction method
3.1 According to the specific construction requirements of the building design and processing of the external wall needs of steel
In the process of construction of reinforced concrete wall insulation, it is necessary to reasonably develop a specific construction plan of reinforced concrete wall insulation, based on the plan to the wall insulation required for the reasonable selection of reinforcing steel, and for the window data for reasonable collection and analysis, the effective realization of the processing and splicing of the window, so that the insulation board can be effectively installed in the reinforced concrete wall, in the buttressing of the insulation board When processing, it is also necessary to effectively smooth the jointed parts and make the corresponding markings, so that the construction can be carried out more smoothly. In the construction, for each part need to be effective cleaning treatment, to prevent because of debris on the construction quality has an impact.
3.2 According to the exterior wall template for the installation of insulation board
In the insulation board installation connection installation, need to be connected to the part of the adhesive coating, to ensure that the insulation board connection installation of dense, so as to prevent the appearance of cracks. Insulation board in the connection installation, need to do a good job of anchoring treatment, if in the process of anchoring treatment, found that the anchor reinforcement beyond the reinforced concrete exterior wall, the relevant construction personnel need to be able to exceed the anchor reinforcement part of the anti-rust treatment.
And in the process of external pouring treatment of reinforced concrete for building construction, it is necessary to determine the building elevation and carry out reinforced concrete pouring construction from the top of the building, and in the external position of the wall, a gap opening adapted to the thickness of the floor slab should be reserved. When the formwork is installed, it is necessary to correct the processing of each formwork to guarantee the solidity and tightness of the formwork installation, and the insulation board and the formwork also need to fit closely to achieve close reliance.
3.3 Pay attention to the level when carrying out reinforcement concrete pouring
In the process of pouring the same reinforcement, it is necessary to adopt the method of layered pouring, divide the pouring area well and adopt the way of continuous pouring for reinforced concrete. To ensure the uniformity of each layer and each area of reinforced concrete pouring, the thickness of the pouring should be thin and thick, generally speaking, the thickness of the reinforced concrete poured should be controlled between 0.8-1m. And in the process of pouring down the reinforced concrete, it needs to be poured from both sides to the middle, and the angle of pouring down the material should be controlled on the same level as far as possible. The height of pouring needs to be set reasonably in accordance with the design requirements to ensure the smoothness and flatness of the reinforced concrete surface.
After the reinforced concrete is poured, it is necessary to carry out corresponding monitoring treatment, and only under the premise of ensuring that the strength of reinforced concrete meets the standard requirements can the demoulding process be carried out. When demoulding, the order should be adopted from outside to inside. If there is a part of the insulation board fall or missing, it should be timely replenished with the corresponding insulation materials.
3.4 Moisture monitoring and quality inspection
When the demoulding step is completed, the humidity of the sampling points should be monitored and recorded regularly, and if the humidity is too low, water spraying should be carried out. Finally, quality monitoring should be carried out. The concrete surface must be flat and smooth, and there should not be slag dropping, exposed tendons, unevenness, frequent holes, etc.
4. Conclusion
Through the analysis of this paper, it can be understood that, as China’s traditional exterior wall insulation construction technology in the practical application of many problems.
Therefore, it is necessary to use the construction of reinforced concrete wall insulation construction technology, in order to ensure that the technology can be reasonably applied, it is necessary to fully meet the relevant construction needs, the selection of suitable reinforced concrete insulation construction materials, the reasonable installation of the exterior wall insulation panels, layered concrete pouring, the development of a specific construction plan, control the quality of construction of reinforced concrete exterior wall insulation construction In this way, we can effectively guarantee the stability of reinforced concrete wall insulation construction, so that the steel structure building can be reasonably constructed and developed.