EPS plastered to external thermal insulation quality problem analysis and research
Wu of the sea blue edges even design and research institute of 201204
As per capita resource shortage of the country, the energy shortage has severely restricted the development of our national economy, in this premise for alleviating the our country the conflict of the energy shortage and improve the people's living quality, reduce the environment pollution, a sustainable development strategy, the energy conservation of the building as a residence construction in China's development of a long-term national policy bai promotion to spread. The energy conservation of the building is an important means of exterior wall thermal insulation system, among the more widely used is plastered EPS of exterior wall thermal insulation system. But, a lot of the EPS plastered external wall thermal insulation engineering, different degree of appeared quality problem such as craze, fall off. This paper mainly to the EPS plastered external wall thermal insulation quality problems are analyzed and studied.
Keywords: EPS plastered external insulation quality problems
Along with the rapid development of China's national economy, the people's living standards improved, and the consumer demand for housing is not the rapid expansion of up, residential construction in our country has become a new national economic growth. But, with housing consumption growth, people to housing comfort requirements also more and more high, a lot of air conditioning and heating equipment purchase and large and medium-sized city central heating of development, they have a lot of energy consumption.
As per capita resource shortage of the country, the energy shortage has severely restricted the development of our national economy, in this premise for alleviating the our country the conflict of the energy shortage and improve the people's living quality, reduce the environment pollution, a sustainable development strategy, the energy conservation of the building as a residence construction in China's development of a long-term national policy bai promotion to spread. The energy conservation of the building is an important means of exterior wall thermal insulation system, among the more widely used is plastered EPS of exterior wall thermal insulation system. But, a lot of the EPS plastered external wall thermal insulation engineering, different degree of appeared quality problem such as craze, fall off, it comes down, the root cause of these problems arise mainly in the following aspects.
A, insulation board quality and its fixed problem
1, insulation board of quality
After years of practice, EPS plastered of exterior wall thermal insulation system formed a set of relatively complete standards and technical regulations, experience shows that, every square metre plank capacity should be not less than 18 kilograms, but, in many engineering application only 15 kg of often, or even individual engineering application in less than 12 kilograms, plank capability of heat preservation and strength can not reach the technical requirements.
2, insulation board fixed problem
Engineering in wall body for fixed EPS sheet many methods, using different fixed method, has fixed effects are also different. Generally speaking, the use of adhesive in quality, use felt way is the most reliable effective way. In addition to bond, the way of the project, according to the different conditions and bilge plug screws, steel wire nets fixed, will make fish tank and the plank concrete way up in, etc. In theory, these methods as long as use proper can make relatively satisfactory fixed effect, for a fixed process, all of the fixed method require plank and metope keep the maximum fixed area.
Use fixed plank binding method, form per square metre pulling force far greater than use bilge plug screws or simple fish tank can resist the pull. In the engineering project for EPS exterior insulation system life general requirement 25, 30 years, but, because of the constant change of the external environment, but, decorated with the surface coating and is unable to achieve the fixed number of year requirements, in the coating to fixed number of year life, and direct contact with the outside world of polymer will take on the surface of EPS sheet protection, therefore, it's the strength, water resistance and weather resistance and resistance to cold sex and deal with the flexibility of the structure swell-shrink aspects technology index demanding.
Second, the problems in the construction of
1, construction cost compressed too low, the construction units purchasing material shoddy
In before construction, for all kinds of engineering cost can be clear calculated, because human cost is basically fixed, other EPS, glass fiber nets, the expense proportion of materials is relatively low, therefore, the construction unit will lead to cost savings focused on the use of adhesive, inferior adhesive use lead to serious engineering quality problems.
2, the basic level processing technology is so poorly
External thermal insulation of the adhesives each square metre of dosage due to dig wall of cement mortar with flat and different situation, wipe flat as opposed to not to wear away the amount of nearly 2 kg difference. Therefore, wall body has a direct effect on the basic level processing technology to the amount of bonding quality and adhesive. Now in many engineering construction, for external wall grassroots don't do plaster processing, direct heat, at this point, if indoor decoration need stiletto, can destroy the thermal insulation layer.
3 and the construction units in order to guarantee their lowest cost of construction and benefit maximization, in insulation engineering unit cost for death, increase water and the dosage of cement, reduce the proportion of polymer mortar polymer, resulting in serious lower quality.
4, use normal be bored with child for polymer mortar paste construction
Because ordinary water resistance and elastic be bored with child is relatively low, in plaster after construction, be bored with child extremely easy craze, and the thermal insulation layer of decorative surface of adornment effect produces serious influence. Therefore, in construction process, should be the first to use water resistant flexibility be bored with child make level, followed by elastic coating, in EPS outer form a layer of elastic protection layer.
Three, for EPS exterior insulation system common quality problem analysis
1, the use of material
Due to the economic interests of the drive, the construction units in engineering bidding adds a false report, choose relatively cheap cost of external thermal insulation materials for construction of inferior, in construction, shoddy, jerry situation occurs frequently, and cause a lot of quality problems appear.
(1) insulation board
(1) EPS low density
Individual construction units in warm system construction is used when 15 kg/m2 the following EPS of polystyrene as wall insulation materials. Due to the low density board, and the deformation resistance to impact extremely easily ability is bad, causing the insulation wall craze.
(2) the Chen don't have enough time
EPS of polystyrene standard requirement of process plank came under natural conditions shall be approved by the China 42 days in 60 ℃ or steam Chen five days, but individual projects in order to catch period, just production out of the EPS directly by fixed on the wall. Cause EPS of polystyrene dimension stability is weaker, the thermal insulation system in after the completion of the continue to contraction deformation. Cause thermal insulation wall craze.
(3) material pulverization
Part of the project due to the construction period is longer or the next year, construction cause for EPS of polystyrene table of flour, lead to plank paste rickety or mortar paste stick 1 rickety, cause thermal insulation layer falls off, plaster mortar cracking and other accidents.
As the heat preservation system of adhesive and new materials, in the engineering project mainly by the two products: a factory production by the liquid adhesives, another kind is in the factory dry powder premixed good adhesive. Acrylic acid emulsion, branches of additive and as aggregate silica sand is the main components of the adhesive, they often appear the following problems:
(1) in the configuration polymer emulsion used when the price is low with a vinyl acetate ethylene resin alternative of acrylic resin, lead to a mixture of the adhesives, permanent, the rapping water resistance performance can not reach the standard request, creates the EPS fixed rickety or not durable, cause thermal insulation layer craze.
(2) the configuration dry powder materials, not in proportion to operation, reduce dry powder material of additives in quantity and variety. Affect the quality of the adhesive stable and crack resistance. Thus affect the entire heat preservation system of durable fixed number of year.
(3) the silica sand aggregate used the untreated sand and iron ordinary quartz sand. Iron composition is higher, easy oxidation reaction, destroy the resin emulsion adhesive molecular, make its various performance indicators down gradually. Cause thermal insulation system open
Crack, fall off.
(4) some adhesive felt too big, strength is too high. Cause contraction deformation is big, easy to cracking insulation board, cause thermal insulation layer craze.
2, construction operation
(1) the basic metope screed-coat not smooth, facade not vertical, Yin and Yang Angle not the phenomenon such as founder, cause EPS of polystyrene and metope contact undesirable, and raising up or board seam is too large, the insulation board after stick rugged, plaster layer caused by uneven thickness crack.
(2) the wall sticks has the oil pollution, dust, take off such as film-former, in the wall and binding mortar isolation effect between up, the influence of polystyrene and grassroots EPS wall body between the rapping, cause the drum, and even fall off.
(3) polystyrene storage time is long, the surface floating dust or oily be soiled processing not clean, the direct plaster layer rubber paste. Cause empty drum craze.
(4) not proportional allocation binding mortar and plaster mortar. Many water or more cement, reduce the bonding mortar bond strength and dispersion of flexible rubber paste cause thermal insulation layer the drum, and even fall off.
(5) rubber paste paste a long time, the state at half solidification plaster and bonding strength is reduced.
(6) and Angle is not use double deck nets cloth bag each 200 mm practice, but single nets straight bag. Yin and Yang Angle caused cracks.
(7) Windows and doors hole not inclined to stick four 200-nmX3OO 'rm enhancement nets cloth, do not make FanBao mouth, cause a crack.
(8) in order to catch period, at low temperature for thermal insulation construction, make the binding mortar, plaster mortar, be bored with child produce frozen clots, spring back after thawing temperature produced changes, resulting in crack surface insulation layer even fall out.
(9) the window sill board, the concrete component, its outstanding metope line leak heat treatment, cause thermal bridge phenomenon, cause the metope inside the damp, mildewy, condensation, etc.
To sum up, the exterior insulation quality problem though exist to completely solve and also is not very difficult. From the domestic affairs, as long as strengthening management, steady promotion, as a practical way of heat preservation, will be in the civil construction energy conservation work play an important role.
 HeZhongKao. Shallow weak EPS plastered outer wall insulation construction technology application [J]. Construction energy conservation, 2008
 wang wei, HaoZhongBin. EPS exterior insulation some problems encountered in the construction of the [J]. Construction energy conservation, 2009, (5).
 QuHuiFeng. EPS plastered exterior insulation system construction of [J]. J architecture construction, 2008, (7).
 JiYongMing. EPS exterior insulation construction technology improvement and discusses [J]. Construction technology, 2008, (8)