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The latest formula and construction process of external wall thermal insulation bonding mortar

External wall insulation bonded mortar

 

Adhesive mortar is made of cement, quartz sand, polymer cement and various additives through mechanical mixing. Adhesive mainly used for bonding insulation boards, also known as polymer insulation board bonding mortar. The adhesive mortar is compounded by high-quality modified special cement, various polymer materials and fillers through a unique process, which has good water retention and high bonding strength.

 

Four characteristics

1、It has a strong bonding effect with the base wall and insulation boards such as polystyrene boards。

2、And water-resistant freeze-thaw resistance, good aging resistance。

3、It is convenient for construction and is a very safe and reliable bonding material for thermal insulation systems。

4、No slipping during construction. Has excellent impact resistance and crack resistance。

 

Introduction to the formula of external wall thermal insulation bonding mortar

 

Exterior wall insulation system is currently the most widely used energy-saving technical measure in the energy-saving of building walls in my country. It is being popularized in a large scale across the country and has made a huge contribution to building energy-saving. However, the external thermal insulation bonding mortar currently sold on the market generally has poor thermal insulation effects, low adhesion, and high cost, which has a huge negative effect on ensuring the quality and safety of external thermal insulation projects. Influence。

 

External wall thermal insulation bonding mortar formula

 

①External wall thermal insulation bonding mortar production formula

High alumina cement 20 copies
Portland cement 10~15 copies
sand 60~65 copies
heavy calcium 2~2.8copies
Redispersible latex powder 2~2.5copies
Cellulose ether 0.1~0.2copies
Hydrophobic agent 0.1~0.3copies

②External wall thermal insulation bonding mortar production formula

Portland cement 27copies
sand 57copies
heavy calcium 10copies
slaked lime 3copies
Redispersible latex powder 2.5copies
Cellulose ether 0.25copies
wood fiber 0.3copies

③External wall thermal insulation bonded mortar production formula

Portland cement 35copies
sand 65copies
Redispersible latex powder 0.8copies
Cellulose ether 0.4copies

 

 

Construction instructions for external thermal insulation mortar

 

 

1. Construction preparation

1、Before construction, the dust, oil, debris, bolt holes, etc. on the surface of the base should be removed, and the spraying should be carried out after the water test has no leakage. The thickness of the interface agent used for the concrete wall is 2mm-2.5mm;

2、The holes should be smoothed, and the base should meet the standard of general plastered base;

3、Impermeable mortar (or cement mortar) powder for the window and door of the exterior wall;

4、Steel wire mesh spread to the window, door 30㎜-50㎜;

5、Powder the large-area exterior wall first, and then powder the corner protection (use impermeable mortar or thermal insulation mortar);

6、For the setting of expansion joints, the height interval of one interconnecting ring (plastic strip) on each layer shall not be greater than 3M;

7、Facing bricks may not be provided with joints from an aesthetic point of view, such as setting expansion joints on the surface layer (the upper opening of the facing bricks must be sealed, and waterproof silicone is used);

8、The plastic strips are glued on with silica gel (the silica gel itself is waterproof) and the steel mesh does not need to be disconnected。

 

2. Construction process of thermal insulation mortar

1、Base treatment – set square, make ash cake – interface agent base layer – 20㎜ thick thermal insulation mortar (apply in two times) – electric hammer drilling (10# drill hole depth should be 10㎜ greater than nails, and the length of the drill bit is generally 10㎝) – laying steel wire mesh – applying 12㎜~15㎜ anti-cracking mortar – acceptance, watering and maintenance;

2、Base treatment: (1) Remove floating dust, slurry, paint, oil stains, hollows and efflorescence on the base walls that have passed the acceptance test, and other materials that affect the adhesion; (2) Check the wall with a 2M ruler, the maximum The deviation value is not more than 4mm, and the excess part is chiseled or smoothed with 1:3 cement;

3、Set the formula and find the rules to make the ash cake and do the same base treatment. The thickness of the ash cake depends on the thickness of the insulation layer. Use 1:3 cement mortar as the corner protection at the front corner of the powder insulation mortar, and then apply the insulation mortar.

 

3, powder insulation mortar

1、When mixing thermal insulation mortar composite materials, the gray-water weight ratio should be determined according to the ambient temperature and the dry humidity of the base. The general powder-to-material ratio is powder: water = 1:0.65. Complete in 4 hours; 2. The mixing time is 6-8 minutes. The first time the dosage should not be too much, it must be mixed with water while stirring to control the consistency; 3. Determine the construction thickness and apply 2㎜~2.5㎜ thick interface agent , followed by powder thermal insulation mortar, (if the thickness exceeds 20 mm insulation layer, the first layer of thermal insulation mortar should be applied from bottom to top, and the operator should use wrist force to compact it), when the material reaches the final setting, that is, the thermal insulation mortar When the layer reaches solidification (about 24 hours), you can apply the second coat of thermal insulation mortar (according to the first coat method). Scrape the surface with the ruler according to the standard ribs, and fill the uneven parts with thermal insulation mortar until it is flat; 4. Do a good job of maintaining the thermal insulation layer according to the ambient seasonal temperature, and wait for the thermal insulation layer to finally set for about 24 hours before watering and moistening. Keep the surface from whitish, water it twice in the morning at 8 o’clock and 11 o’clock in summer, and water it twice in the afternoon at 1 o’clock and 4 o’clock in the afternoon. For parts that are prone to collisions such as aisles, temporary fences should be placed to protect the insulation layer。

 

4. Laying and installation of galvanized wire mesh and matching insulation nails

1、When the insulation layer reaches its strength (about 3 to 4 days later) (it has a certain strength and dries naturally), the elastic line is divided into grids

;2、Drill holes with an electric hammer at a certain interval (the hole distance is about 50cm, plum blossom shape, and the depth of the hole is about 10cm from the insulation layer);

3、Lay galvanized wire mesh (the curved side faces inward, and the joints should overlap each other by about 50㎜~80㎜);

4、Install insulation nails according to the original hole distance and fix them with steel wire mesh。

 

5. Construction of anti-seepage and anti-crack mortar

1、Construction preparation of anti-seepage and anti-cracking mortar plastering surface layer: the plastering of the anti-cracking mortar surface layer must be carried out after the thermal insulation mortar has fully solidified for 3 to 4 days.

2、The anti-cracking mortar should be used immediately after mixing, and the parking time should not exceed 2 hours. The ground ash should not be recycled, and the consistency should be controlled at 60㎜~90㎜;

3、The anti-cracking mortar surface should be cured according to the temperature of the environment and seasons. After the material is finally set, it should be watered and cured. In summer, the watering and curing should not be less than twice in the morning and twice in the afternoon, and the interval between watering and curing should not be greater than 4 hours.

 

6. Facing bricks

1、Play the grid line, and finish it 1 day in advance to wet it with water;

2、Check whether the anti-cracking mortar is compacted before tiling, and there must be no leakage, pitting, hollowing, etc;

3、Bricks should be selected and trial paved before tiling, and cement adhesive should be used. The mixing ratio should be cement: adhesive: sand = 1:1:1 weight ratio. When the construction temperature difference is large, the mixing ratio can be adjusted appropriately. It is strictly forbidden to add water to the configuration of the adhesive;

4、After paving the tiles, the wall surface and joints should be cleaned in time, and the width and depth of the joints should meet the design and specification requirements;

5、Clean the wall, pull-out test, acceptance.

 

Tool preparation:

1、Forced mortar mixer, vertical transport machinery, horizontal transport vehicles, nail guns, etc.。

2、Commonly used plastering tools and special inspection tools for plastering, theodolite and wire setting tools, buckets, scissors, roller brushes, shovels, brooms, hand hammers, chisels, paper cutters, line rulers, rulers, probes, steel Ruler etc。

3、Hanging basket or special insulation construction scaffolding.

 

Frequently Asked Questions about External Wall Insulation Bonding Mortar

Why is the insulation falling off?

1、Basic structure factors. The outer wall of the frame structure is prone to damage to the insulation layer caused by the deformation of the masonry at the joint between the concrete beam column and the masonry. The openings of the scaffolding are not solidified, and the local base of the insulation layer is not strong enough to be damaged. The external wall decoration components are not firmly fixed and shifted, forming a push-pull effect, causing the insulation layer to be partially hollowed out, causing long-term water seepage after cracks, and eventually causing the insulation layer to fall off;

2, Improper anti-pressure measures. The surface load of the insulation board is too large, or the anti-wind pressure resistance measures are unreasonable. For example, the non-nail-bonded bonding method is used for the exterior walls of coastal areas or high-rise buildings, which can easily cause the insulation board to be damaged by wind pressure and hollow out;

3、Improper handling of the wall interface. Except for the clay brick wall, the other walls should be treated with interface mortar before applying the slurry insulation material, otherwise the insulation layer will be directly hollowed out or the interface treatment material will fail, resulting in the interface layer and the main wall being hollowed out, and the insulation layer will be hollowed out. drum. The surface of the insulation board also needs to be treated with interface mortar, otherwise it will cause local hollowing of the insulation layer.

 

Wy is the plaster cracked?

1、material factor. The density of the thermal insulation board for external wall insulation should be 18~22kg/m3. Some construction units will shoddy and use thermal insulation boards below 18kg/m3. The density is not enough, which will easily lead to cracking of the plastering mortar layer; the natural shrinkage time of the thermal insulation board is In the natural environment for up to 60 days, due to factors such as capital turnover and cost control of the production company, the insulation board with an aging time of less than seven days has been placed on the wall. The plastering mortar layer on the board is pulled and cracked;

2、Construction Technology. The flatness of the surface of the base layer is too large, and the adjustment methods such as the thickness of the adhesive, multi-layer board, and surface grinding and leveling will lead to defects in the insulation quality; the dust, particles and other substances on the surface of the base layer that hinder the adhesion have not been treated at the interface; the insulation board is bonded The area is too small, does not conform to the specification, and cannot meet the quality requirements of the bonding area; when the rice surface mortar layer is constructed under exposure or high temperature weather, the surface layer loses water too quickly, resulting in cracks;

3、The temperature difference changes. The thermal conductivity of the expanded polystyrene board and the anti-crack mortar is different. The thermal conductivity of the expanded polystyrene board is 0.042W/(m K), and the thermal conductivity of the anti-crack mortar is 0.93W/(m K). The thermal conductivity differs by a factor of 22. In summer, when the sun shines directly on the surface of the plastering mortar, the surface temperature of the plastering mortar can reach 50-70°C. In case of sudden rainfall, the temperature of the mortar surface will drop to about 15°C, and the temperature difference can reach 35-55°C. The change in temperature difference, the temperature difference between day and night, and the influence of seasonal air temperature lead to a large difference in the deformation of the plastering mortar layer, which is prone to cracks.

 

Wy are the bricks on the outer wall hollow and falling off?

1、Temperature changes. The temperature difference between different seasons and day and night makes the decorative bricks affected by the three-dimensional temperature stress, and the decorative layer will produce local stress concentration on the vertical and horizontal walls or the junction of the roof and the wall. The local extrusion of adjacent bricks will cause the bricks to fall off;

2、material quality. Because the plastering mortar layer was deformed and hollowed out, the facing bricks fell off in a large area; the composite wall was formed due to the incompatibility of the materials of each layer, and the deformation was not coordinated, resulting in displacement of the facing bricks; the waterproof measures of the outer wall were not in place. Cause moisture to infiltrate, cause freeze-thaw repeated freeze-thaw cycles, cause the tile adhesive layer to be damaged, and cause the tile to fall off;

3、external factors. Some external factors can also cause the facing bricks to fall off. For example, the uneven settlement of the foundation causes the deformation and dislocation of the walls of the structure, resulting in severe cracking of the walls and the falling of the facing bricks; natural factors such as wind pressure and earthquakes can also cause the facing bricks to fall off.


Post time: Feb-09-2023
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