Plastering on aerated concrete wall surface processing

1 scope

This standard applies to aerated concrete blocks and aerated concrete wall surface plastering.

2 construction preparation

2.1 materials and equipment

2.1.1 cement: No. 325, Portland or Portland slag cement.

2.1.2 sand: sand; aperture 5mm sieve before use, and clay content of not more than 5% shall not contain debris.

2.1.3 lime cream: one month before using massive lime cream and pour ash 3mmx3mm with aperture of sieve filters. Or use the pulverized quicklime, stored in the sedimentation tank, soaked in water for not less than 3D, making it fully cured, lime paste may contain particles and other impurities that are not cured. Gypsum mortar in advance into a mortar, mixed with cement mortar mix.

2.1.4 paper reinforced white bars and toilet paper bar, soaked in water before use and mash. Overlay paper bars suitable for grinding fine, does not contain impurities. Straw, wheat straw should be tough, dry, free of impurities, the fibre length must not exceed 30mm. Straw, wheat straw before using the lime dipping.

2.1.5 Ma DAO: must be uniform, flexible, dry, free of impurities, 10~30mm in length. Flapping loose.

2.1.6 anti-cracking agent: anti-cracking agent should meet the performance targets set in the programme for construction, such as pH value, viscosity, density, initial setting time, volatile components for testing.

2.1.7 fly ash, perlite powder (density is 40~300kg/m3), 107 rubber and so on.

2.1.8 main machines: General should has mortar mixer, and Shang material frame, and vertical transport mechanical, and sieve (aperture for 50mmx50mm, and 30mmx30mm), and hand sprayer, and supporting gray Board, and wood wipe child, and iron wipe child, and by feet Board, and half big barrels, and iron, and shovel, and Yin angle wipe child, and Yang angle wipe child, and small round angle (triangle iron) stroked child, and hair brush, and big bar, and small bar, and supporting Board,.

2.2 operating conditions: to verify the main structural engineering inspection and access to structured inspection procedures, before plastering.

2.2.1 aerated concrete wall repairs completed, completion of door and window frames, partition walls, plumbing, electrical, piping, Fire Hydrant Cabinet, distribution box related embedded parts, wood cabinets, tile installation, Embedment work.

2.2.2 prior to plastering wall was tick cut line Groove, made perfect. Check for proper door and window frames, install a solid connection, gap between door and window frame and wall 1:3 cement mortar or impaction of 1:1:6 cement mortar-sealed.

2.2.3 according to the grey wall height, scaffolding, high stools for set plaster. Operating platform and wood should be 200~250mm left the wall and door and window openings to facilitate operations. Wood should be stable, firm and reliable.

2.2.4 winter construction of plastering mortar and anti-cracking agent insulation measures, operating the place cold, freezing facilities. Temperature should not be below 5 degrees Celsius.

3 operational processes

3.1 process:

Treatment of base → water wetting → → ash cake, Red labels reinforcement cement kick →

Door window corner → cement mortar scratch coat spray head → anti-cracking agent →

Repairing walls, trough the hole → cover grey spray two times → anti-cracking agent

3.2 base treatment: check before plastering aerated concrete walls, loose, mortar, not full of seams and head joint under the beams, plates, padded Compact with 10% 107 adhesive mortar mixed with water. Tongue of exposed wall ash blown away, rejection of chisel flat-convex parts of the wall. Crater wall inequality, block short of cord angle and tick pipeline slot cut, hole, plastic ash renovation of dense, smooth. Sizing with a Board check the vertical deviation and smoothness of the wall, plaster base treatment intact.

3.3 water wet: the clean wall surface, score over watering moist. Because of aerated concrete block water absorption speed from fast to slow water slow and long duration, it should increase the number of water, plaster layer has a good setting and hardening conditions, not in the water during the hardening of the mortar was sucked away by aerated concrete. Infiltration of water to water depth 8~10MM block is appropriate, and watering should be in plaster for the previous day. Event of dry weather, plaster wall is still dry, not wet, should be sprayed over water, plaster walls do not float, to mortar strength growth, less prone to hollowing and cracks.

Spray brush and again immediately after mixing water of 20% 107 adhesive cement slurry, and then began plastering.

3.4 paste ash cakes, Chong tendons: Care Board test over different parts of the wall vertically, flat, with the actual height of wall ash cake and punch the number of bars. Average height and the distance to 1.8M is appropriate. 1:1:6 cement-lime mortar, gray 100mm square pie. Thickness of the ash cake to meet the requirements of plastering the walls reach the verticality is appropriate. Ash cake Board find up and down vertical, horizontal plates, on foot or line level, after first. Ensure the surface of the walls, ash cakes in the same plane, as a basis for screed Strip.

Screed Strip: in accordance with the already good ash cake, from the horizontal or vertical direction between each gray pie mixed with cement mortar screed Strip, repeatedly rubbing, hanging vertically up and down.

3.5 cement mortar skirting, Dado: in cement mortar within height range, brush it again 10% 107 adhesive plain cement slurry mixed with water, immediately 1:1:6 mixed mortar scratch coat, thick 5mm. Then wipe it again (middle gray), and rib rub smooth surface with a wood float-filled hairs. In the middle gray when they reach five or six, 1:1:5 cover grey cement mortar, trowel, calendering, it tastes good with foot flush cutting. After plastering the wall is complete, the wall thickness should be the same, usually in convex wall of ash-5~7mm.

3.6 door window of cement mortar corner: corner of interior door window and door and window sets, cylinder angle, should cement mortar angle, the height shall be not less than 2m, corner edge on each side of a width not less than 50mm, Sun angles, doors and Windows from top to bottom and underside of the lintel to founder. How to brush a mixed with water of 10% 107 adhesive cement, l:1:6 cement mortar base. Second time with 1:0.5:3 cement mortar and reinforced screed. Corner sides stuck on foot, slightly dry and then using mortar cement poured into small fillets (with angle iron beard), edge thickness should be beyond the end of the wall thickness of the ash cover grey, rear flush with the wall surface ash layer.

3.7 ash:

3.7.1 brush mixed with water wall of aerated concrete block of 10% 107 adhesive cement should be timely after plastering, not plain water mud dry and then plastering, otherwise, the isolation layer is formed, is not conducive to grass-roots bonding. When plastering gluten should not be damaged. First time mixing mortar, mix 1:1:6, 5mm thick. Sweep hair or draw lines, conservation, dry, and 1:3 lime mortar, thickness and the gluten-filled level. Or 1:3:9 cement mortar mix to wipe it a second time, walls with a big bumper scrape, rub wood trowel flat. Sizing with a Board examination, require vertical, smooth, Yin, Yang Kok founder, top plate (beam) intersection angle with the wall straight, it tube internal corner straight, smooth and clean.

3.7.2 scratch coat on aerated concrete panel: generally after the screed Strip 4H, first brush of 10% 107 rubber cement mixed with water consumption, then mixed with 1:3:9 mortar scratch coat, the thickness of 6~8mm and plastering with a big bumper in accordance with the standard bar to scrape, rub coarse wood trowel pock marks.

3.8 repair wipe wall surface Shang of box, and slot, and holes; Dang end of gray leveling Hou, should immediately put heating, and electrical equipment of box, and slot, and hole hole around 50mm of end of gray mortar cleanup clean, using 1:1:4 cement mixed mortar put mouth around repair wipe flat align, and founder, and smooth, wipe gray Shi than wall surface end of gray high out a cover surface gray of thickness, ensure slot, and hole around dressing intact.

3.9 spray (first round) anti-cracking agent: anti-cracking agent is to ensure that the wall plastering of aerated concrete does not appear hollow, crack the key measures, the process used to decide according to their specific conditions. When the scratch coat after wiping out immediately with sprayer anti-cracking agent sprayed directly on the scratch coat, anti-cracking agent to mist spray, for spraying evenly, do not leak spray, and is not excessive, concentration. When nozzles tilted upward, and distance from the wall, spraying to ensure even moderate, and it is not washed the plaster layers as appropriate. Anti-cracking agent not to twist spray 2~3h, so as not to damage the surface structure.

3.10 cover gray:

3.10.1 paper reinforced gray overlay: dry bottom ash for about six or seven when the thickness of 2mm cover grey. To scrape a layer of thin, smooth, rough pressure again, and then put it again, from top to bottom, order, compaction, catch the light. Then with an iron trowel smooth, light, and finally with hard plastic trowel smooth lines light. Pollution should be cleaning a clean, not dumped broken lives.

3.10.2 the mortar mix cover: 1:0.5:3 cement mortar overlays, 5mm. Two survived, also in scratch coat dry start five or six cover gray, brushes on the bottom ash of 10% 107 rubber cement mixed with water consumption, followed by cement mortar, trowel, compacting, and catch the light.

3.10.3 cement mortar overlays: brush element when mud, water, 1:2.5 cement mortar in two times with survival, overlay, 5mm.

3.11 spraying (second time) anti-cracking agent: cover gray finished, slightly dry, with initial hardness, generally after the initial setting of the mortar before you shrink, sprayed it again anti-cracking agent in a timely manner. When the temperature is moderate, moist environments, anti-cracking agent can also save not to do.

Winter construction of 3.12: indoor plastering on aerated concrete wall surface, measures should be taken, using a variety of materials shall not be subject to freezing, plastering mortar temperature shall not be less than 5.

Of plastering on aerated concrete wall surface temperature should not be lower than 5 ℃, indoor plaster should be prepared in advance for warmth, heat and cold. In winter by freezing method in construction of masonry walls, in front of the plaster should take measures to thaw. All wall after thawing, and ambient temperature 5 ℃ above, may be carried out on aerated concrete wall surface plastering jobs. Not under negative temperature environment and plastered on the wall not yet thawed.

Winter construction of appropriate ventilation in indoor air, the moisture out. Should have special responsibility for switching Windows and doors, insulation, temperature. Strictly control the indoor temperature, plastering layer must not be allowed to freeze.

4 quality criteria

4.1 project:

4.1.l material of the variety, performance and quality must comply with the design requirements and the relevant provisions of the standard, plaster grades, is in conformity with drawings provided.

4.1.2 the plaster layer and must bond between plaster layer and the substrate, no delamination, hollowing and cracks. Non explosive dust, cracks and other defects.

4.2 Basic project:

4.2.1 surface:

Common plaster: the surface is smooth, clean, Cha and smooth.

Intermediate plasters: smooth, clean surface, Cha flat, corners straight and clear, uniform rough surface texture.

Advanced plastering: the surface is smooth, clean, uniform color, no lines, and gray line straight line angle, founder, clear and beautiful.

4.2.2 corner and doors between the window frame and wall cracks, corner in accordance with provisions of the code. The surface is smooth, smooth. Gaps between the door and window frames and wall packing density, surface roughness.

4.2.3 holes, troughs, boxes, pipes behind the plaster, the correct size, founder, clean, and smooth. Behind the pipeline, smooth and clean.

Section 4.2.4 (seam): width, depth, uniform (seam) is flat and smooth, Leng corners neatly, horizontal even vertical, smooth.

4.3 allowable deviation, as shown in table 9-3.

Aerated concrete wall tolerance table 9-3

Project tolerance (mm) test method

Regular intermediate advanced

1 façade vertical-5 3 2m supporting plate check

2 surface flat 5 4 2 2m m on foot and wedged feeler Gage check

Angular vertical-4 2 3 Yin and Yang with 2m supporting plate check

4 point founder-4 2 20cm feet of yin and Yang and wedge feeler Gage check

5 points (seams) straight-3-5M line and length check

5 finished product protection

5.1 Windows angle finished, cement wash with water on the door window frames, aluminum Windows and doors must be protected against pollution.

5.2 roots above the door frame before plastering 500~600mm range, nailed metal or wood to protect, prevent construction of smash.

5.3 ground, skirting, Dado and pipeline behind the clean up, back prior the radiator brush (spray) overlay with good material.

5.4 aluminum alloy door and window protection film not torn, and gaps between the wall no cement impaction, to prevent corrosion. Design requirements the caulking material, such as when there is no clear, gap fill insulation cotton, inside and outside the rubber seal. To prevent pollution and damage of aluminum alloy doors and Windows.

5.5 material handling light and water down the scaffolding to lift, handle with care, debris removal, tools, materials, neatly, don't crash and pollution of doors, Windows, walls and corner. Not to damage the surface layer, no ash mix on the ground, to avoid bruising. Protect the ground intact.

5.6 protection of embedded parts of the great wall, air grate, pipelines tanks, boxes, electrical, plumbing equipment, the hole he has made not to die.

5.7 before plastering in the setting and hardening to prevent fast-drying, water, impact, pick your chisel. Ensure the ash layer grows to sufficient strength.

5.8 sprayed mortar in the overlay at the bottom of anti-cracking agent before the ashes do not twist, so as not to reduce the effect of crack.

6 quality problems to be noticed

6.1 bond is not strong, hollow, crack: plastering of aerated concrete wall, one of the most common problems is the ash layer bonded with the matrix in prison, hollowing and cracks. Main reason is basic cleaning not clean wash away with water, moist enough, don't scratch grain cement slurry. Due to mortar in strength, the hardening process, their uneven shrinkage stresses, formed in cracks. Improvements can be used to spray crack agents of gum or brushing with about 107 plain cement slurry to increase adhesion, reducing mortar shrinkage stresses, improving the early strength of mortar improved plaster base and mortar mix is the solution of aerated concrete wall surface hollow, crack the key. While the surface tensile strength of mortar improved enough to resist the shrinkage stresses on the surface of mortar, mortar strength growth, capable of withstanding the effects of shrinkage stress, thus preventing the air drum, desiccation, emergence of cracks.

6.2 the plaster layer too thick: plastering layer thickness significantly in excess of the prescribed, especially coated concrete, plastering crack. Plastering layer thickness should be controlled by Chong tendons, keep 15~20mm. Operations should be stratified and intermittent plastering every thickness for 7~8mm should first pass ash after the final setting and then put it again, never again.

6.3 frame edges are not grey or gray solid, embedded spacing between wood bricks, wooden bricks loose repeatedly switch vibration hollowing and cracks on both sides frame: doors and Windows should be sewn as a process by the person in charge, wood bricks must be embedded in a concrete block, with the wall placed on the required spacing. Aerated concrete wall around the door frame should be made of reinforced concrete column, column embedded in wooden block is most appropriate.

6.5 wipe gray tie than using not right, Foundation gray of strength too high, makes gray layer appeared empty drum, cracking: improved approach: the layer gray of tie than to suitable, especially Foundation gray of material, to priority used and added gas concrete of material performance phase close of material, its strength, and modulus and contraction rate basic close suitable, and wipe gray layer strength too high, makes grass-roots and Foundation gray Zhijian easy produced big area empty drum, and crack. So the proper mix is necessary.

6.5 plastering bubbling with obvious trowel marks, wall flowers::

6.5.1 after finishing the cover gray, also does not have the strength, working with tight ash layers have not received water, light appeared after popping. Cover gray after the ash layer has a certain degree of hardness, deformation is small, gray layer of surface water has been received, then compaction, catch the light.

6.5.2 excessively scratch coat is dry, and no water permeable, overlay after the ashes, water is absorbed by the scratch coat, so easy when lines and light leakage. When ash should begin to cover five or six usual grey, if it is too dry to fit water spray. Cover gray should have a good time, eliminating lines.

6.5.3 cream soak gypsum mortar and lime powder, to chronic, excessive lime with lime materials and impurities without filtering, gypsum mortar curing time is short, especially for grinding lime powder, not required soaking time, fire particle fails to fully cure, wall water continue to ripen, volume expansion caused by plastering the surface burst, flowering occurs, bursting the skin. Cream ground lime gypsum mortar, or prepare, maturing period must meet the qualifying days. Prepare in advance. Gypsum mortar shall not be not fully ripen on the wall.

6.6 plaster surface, angle not perpendicular, not founder of yin and Yang: the main reason is hanging before the plaster line, ash cakes, Chong tendons are not serious, Chong tendons time too short or too long, resulting in shrinkage of different appears rough, angle is not straight, not founder of yin and Yang. Before plaster application supporting Board and on foot on the grey wall surface size prediction mapping, arranging angle two different surface layer thickness of yin and Yang and the founder, earnestly ash cakes, Chong tendons. Corner square sets of yin and Yang. Wall vertical, flat, angle founder of yin and Yang.

6.7 Dado, skirting and cement hands out the wall sill plate thickness are inconsistent, it tastes good and Burr quarrel not founder, roots appear eight glyphs Askew: the main reason was operating fine, not complying with the provisions of hanging wall vertical, not party, Latrun not straight lines attempt to find rules. Improvement: while the operation requiring careful hanging,,. Catchy with a anti-scraping, compaction, catch the light. Cut the roots. Make it square and straight.

6.8 pipe behind the plastering inside, not only, it tube cracks, Heating tanks on both sides of the upper and lower plaster not fluent: improvements are, line the wall required casing, where plumbing installed in advance before Ash site and cleaned. Groove, Duo-sized hanging straight, level, pressure. Edges neatly, don't dump jobs.

7 quality records

This standard shall meet the following quality records:

7.1 cement factory prove and test reports.

7.2 sand material proof.

7.3 fly ash and expanded Pearlite material proof.

7.4 adhesives, anti-cracking agent factory certificate.

7.5 quality inspection and assessment of records.