Common knowledge of coating: some problems in the construction of polymer coating

It is suggested that the polymer waterproof coating is a mixture of non-toxic and pollution-free polymer organic materials and a certain proportion of powder Because of its good bonding performance with the cement based base, and the polymer waterproof material to adapt to various waterproof requirements, it has been widely used In order to make the polymer waterproof coating better meet and serve the engineering waterproof requirements, it is necessary to further discuss and understand its construction characteristics I factors affecting the quality of waterproof layer: the film-forming of polymer waterproof layer has similar characteristics with other waterproof coatings, i.e prevention Paint agent, top 10 Chinese wall paint brands Recommended introduction: interior wall paint and exterior wall paint can achieve beautiful, clean and pleasant effects, but the effects in different environments are different, so the color of the paint will be different There are ten brands of Chinese paint, ten brands of global paint, ten brands of Chinese wall paint, and ten brands of Chinese paint, Famous trademark of Chinese paint and coating In private rooms, most of us choose according to our own personality, personal hobbies and living habits The younger generation will choose the interior wall paint with rich colors and bright colors, while the older ones will have some working experience Coating home news: polymer waterproof coating is a mixture of non-toxic and pollution-free polymer organic materials and a certain proportion of powder Because of its good bonding performance with the cement based base, and the polymer waterproof material to adapt to various waterproof requirements, it has been widely used In order to make the polymer waterproof coating better meet and serve the engineering waterproof requirements, it is necessary to further discuss and understand its construction characteristics I factors affecting the quality of waterproof layer: The film-forming characteristics of polymer waterproof layer are similar to those of other kinds of waterproof coatings That is to say, the film-forming of waterproof layer depends on the surface quality of membrane, that is, the surface quality assurance of waterproof building, the process of waterproof coating coating, and the protection and durability of waterproof layer after forming, The quality factors that affect the waterproof layer of polymer waterproof coating are: the quality of waterproof material itself: the amount of raw materials, whether the mix ratio is appropriate and correct Surface shape of waterproof base course: refers to the slope, flatness, edge angle and detailed surface of the surface to be waterproof Quality of waterproof base course: refers to the internal quality of base course, whether it is firmly combined with the structure without hollowing, cracking, layering, peeling, surface smoothness, smoothness, etc The process and environment of film forming process refer to the process operation method of multiple film forming processes, the process quality of lamination between passes, the control of harmful environment, etc Process and end protection of waterproof layer: the construction process of waterproof coating layer is often in the cross environment of multiple types of work, which requires the protection of the whole process At the end, it is necessary to construct the protective layer in time to ensure the construction results 2、 Analysis on the causes of common construction quality problems and the ways to overcome them According to the analysis of the reasons for the quality of the waterproof layer of polymer waterproof coating, there are many factors In addition to checking the quality of materials according to the regulations and spot check, this paper mainly refers to the common construction quality status quo in the construction site after the completion of the base course, and summarizes the overcoming and treatment methods of construction practice （1） Quality problems caused by improper quality of the base course 1 Cracking of the waterproof membrane: generally occurs at the water outlet, around the embedded parts, the installation joints of the prefabricated objects, the places where the pipes are interpenetrated, etc due to temperature deformation, structural stress, weak embedded parts, false secondary pouring, changes in the pipes or facilities, the cracking and cracks of the structure cause the cracking of the waterproof membrane Overcoming method: during the acceptance inspection at the basic level, it is necessary to understand the structure of the building structure, strengthen the inspection of the parts with appropriate cracks, and negotiate with the design to strengthen the waterproof operation of this part, such as setting the waterproof coating reinforcing layer 2 Irregular waterproof layer damage and crack: the occurrence position is uncertain and the crack is irregular It is mainly because of the hollowing and cracking of the surface cement mortar of the structure, which leads to the cracking of the waterproof membrane; or because the area of the surface cement mortar is too long, which cracks under the effect of temperature, which leads to the cracking of the waterproof membrane Overcoming method: check the surface quality of the base course in detail before operation to see if there are hollows and cracks Whether there is a separation joint measure for a large area of base course 3 External corner trauma: because the external corner of the base is relatively sharp, and the arc angle is not made according to the specification requirements, the external corner is not easy to hang and adhere the coating of sufficient thickness, and the sharp angle is easy to be damaged by external force, resulting in the defect of the waterproof layer Overcoming method: the external corner of the base course must be accepted according to the specified arc angle, and the unqualified ones shall be repaired During the construction process, the protection of the external corner coating shall be strengthened, or the reinforcing layer of cloth tire shall be added, such as in the crossing of frequent people and logistics 4 Exposed sand on the surface of coating: some base courses are free of iron troweling and exposed sand particles; sand particles protrude on the coating layer, making the waterproof layer incomplete or vulnerable Overcoming method: if there is sand bursting in the base course inspection, it can be removed by grinding 5 There are sharp edges on the surface of the coating: the surface of the base course is rough and uneven, forming a strip-shaped sharp edge at the junction of the concave and convex The thickness of the coating at the sharp edge is insufficient and vulnerable, making the waterproof layer incomplete The method to overcome this problem is to use a sanding wheel to make a sharp edge on the film or to level the concave groove 6 Partial isolation: before the operation of the base course, it is polluted and bonded by a certain thickness of silty materials, such as clay and ground ash, so that the waterproof layer cannot penetrate into the base course and combine with the base course, so that the waterproof layer is isolated from the base course Under the external force, the waterproof layer in this part is broken, causing the integrity of the waterproof layer to be damaged Solution: clean the polluted surface carefully 7 Delamination: refers to the construction sequence that the waterproof layer cannot be bonded with the surface of the structure to be waterproof, which is generally the construction sequence of the waterproof layer first and the structural layer second for the external waterproof and internal coating For example, the baseplate of the basement and the waterproof layer can only be used as the cushion of the structure first, and then as the mortar or fine stone concrete protective layer of the waterproof layer after the completion of the waterproof layer, so as to separate the waterproof layer from the structure surface If the cushion breaks in the process of settlement, the waterproof layer will also break, causing the overall damage of the waterproof layer Overcoming method: to improve the current construction method, see another discussion of the author 8 Structural cracking: refers to the damage of waterproof layer caused by unexpected cracking of the structure, which is caused by the deformation of the structure beyond the allowable bearing capacity of the design Such cracking is often unforeseeable Overcoming method: there is no preventive method before coating operation If it occurs, it is necessary to repair the waterproof layer after structural repair 9 Sand inclusion: uncompacted base course: turn up individual sand particles and mix them with coating to form an uncompacted coating of sand holes Overcome the method; check carefully before construction, and remove or reinforce the surface that is likely to sand in case of any inaccuracy （2） Quality problems caused by improper operation of waterproof layer 1 Falling: generally occurs on the facade or slope with large gradient As the base course is relatively smooth, the first layer of coating is not too thick, resulting in sagging; or the lower layer of coating is applied with the upper layer of coating which is not set, and the lower layer of coating which is not set falls together The local coating thickness is insufficient due to the falling waterproof layer, while the falling coating is easy to produce thick wrinkles, which is high and vulnerable Overcome method: strengthen the thickness and time control of brushing, to prevent the occurrence of sagging The existing sags shall be seriously eliminated and repaired 2 Thick wrinkle: it occurs on the flat, small slope, corner, etc because the base course is uneven and has pits, the ductility of the coating makes the coating concentrate on the low-lying part, which makes the coating thicker The covering of the previous coating makes the water at this place difficult to evaporate At the later stage of the molding, the water at this place finally evaporates and the wrinkle occurs The wrinkle with small thickness affects the appearance quality, and the wrinkle with large thickness occurs The skin will produce a linear thinning of the coating layer To overcome the problem, the low-lying part of the surface should be filled with base coating first, or the coating should be applied locally first, so as to reduce and prevent the accumulation and thickening of the coating 3 Layering and peeling: the waterproof layer is formed by brushing several times If the time of layering is too long, the bonding between times of the waterproof layer is poor and layering phenomenon occurs If the time is long and there is foreign matter pollution and isolation on the layer, the separation of the upper layer may be peeling, and layering affects the internal quality of the waterproof layer If peeling, the effective thickness of the waterproof layer is insufficient Overcoming method: strictly control the time interval of the times according to the actual environmental conditions, prevent the pollution of the surface of the times, and remove the existing pollution The peeled parts shall be cleaned and repaired The method of thickening and strengthening shall be adopted for layering as the case may be 4 Wind pollution and rain separation: during construction in windy days, due to the large amount of dust in the environment, the surface of the coating is stained with silt and other pollutants In the construction process of rain separation system, continuous rainy days lead to a long time interval between layers, which affects the combination of upper and lower coatings Overcoming method: referring to the method of layering and peeling mentioned above, it is to overcome the treatment 5 Sand staining: when the sand stained paint is not set, the sand brought in by the operation will form local sand staining For example, if the foot shoes of the personnel are trampled, or the sand stained result is brought in by the movement of machines and tools, it will slightly affect the combination of the layers, and it will cause coating sand holes Overcoming method: the painting operation shall be withdrawn to the channel, and the construction process shall be provided with measures to prevent trampling Before each operation, it shall be checked, and the part stained with sand shall be cleaned or brushed for reinforcement 6 Dry gathering: it is mainly constructed under high temperature and sunlight, and some surfaces are relatively dry After the coating is applied, the water is quickly evaporated or absorbed, so that the organic powder in the coating cannot play a role, resulting in brittle and scattered defects of the coating Overcome method: Brush operation should avoid the high temperature evaporation period, and spray appropriate amount of water 24 hours in advance for base dry heat 7 Trauma: refers to all kinds of injuries caused by improper protection during each operation, such as collision and strike of personnel or machines and tools Generally, it occurs in areas with large personnel and logistics, such as both sides of the passageway, exit threshold, corner, etc., and it is caused by the next or cross process of coating Overcoming method: reliable prevention shall be provided for the parts easy to be damaged The operation area shall be closed and the route of people flow shall be defined Warning and frequent vulnerable points shall be provided with protective covers The next or surrounding cross operation process shall be protected The measures shall be reliable, effective and complete 8 Reinforced cloth layer separation: it refers to the part designed to be reinforced with tire cloth Because the tire cloth cannot invade the coating layer, the reinforced upper and lower separation or partial suspension is formed It is mainly caused by the reinforcement cloth not being pressed in time or partially rebounded and suspended after the next brushing, or the lower coating is too thin to fully dip and stick the reinforcement cloth Some of the details are complicated, which makes the reinforcing cloth crinkle and can't be completely filled with paint The lap joint of cloth is easy to produce dry adhesion Overcoming method: it is better to select textile type reinforcing cloth, so that the upper and lower layers of coating at the reinforcing cloth can be filled with coating through many textile holes, so as to achieve the adhesion and dissolution between the upper and lower layers The next layer of coating to be laid shall be thickened properly, and the cloth shall be soaked and compacted in time The details shall be provided with anti rebound measures, and the parts with wrinkles shall be coated for several times