Common quality problems and prevention measures of

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Common quality problems and prevention measures of facing brick wall

facing engineering is the primary product composition process in the construction and decoration construction, but there are common quality problems of ceramic material facing and stone material facing in the composition process of facing products

in order to win in the fierce market competition, construction enterprises must rely on outstanding enterprise generality and reputation. It is well known that the generality of construction enterprises is closely related to their products. Therefore, it is necessary not only to strictly control the production and quality, but also to prevent the elucidation and prevention of common quality problems in the process of product composition

ceramic facing bricks are used for the external facing of buildings, which have two effects on the construction of shelter and decoration. However, in case of improper construction, it is easy to show hollowing, scattering, uneven joints, uneven walls, wall pollution and uneven colors

1. Hollowing and scattering

1. Notice analysis

(1) because the quality of the wall decoration surface course of the facing brick is large, there is a large shear stress between the base ash and the base course, and there is also a relatively high shear stress between the adhesive course and the base ash. If the base course is added, the approximate error is large, the base course processing or construction operation is improper, and the bonding strength between the layers is poor, the surface course will produce hollowing, and even fall from the building

(2) the common ratio of mortar is not correct, the consistency control is not good, and the mud content in the sand is too large. On the same construction surface, adopt the different common ratio of mortar, resulting in the cracking and hollowing due to the different shrinkage rate

(3) the durability of each layer of the facing layer is affected by the temperature of the atmosphere. The temperature gradient and thermal expansion and cold contraction from the outline to the base layer will also produce stress between the layers, causing hollowing; If the mortar pasted on the face bricks is not full, the joints of the face bricks are not tight, and the rain seeps out, it will be frozen and shrink, which will easily lead to hollowing and scattering

2. Prevention measures

(1) during the layout and construction, the external wall should be flat and vertical according to the standard of the clean wall as far as possible, which is the premise for the creation of the decorative construction

(2) before using, the tiles must be washed and cleaned, soaked in water overnight, and dried (dry outside and wet inside). Using non soaked dry bricks, there is probably ash deposition, and the mortar is not easy to bond, and because the face brick has strong water absorption, the water in the mortar will be quickly received and dropped, so that the adhesion between the mortar and the brick is greatly reduced; If the face bricks are not dried after soaking, the wet face bricks will generally contain water, which will cause the floating of the face bricks when they are pasted, which can lead to the hollowing of the face bricks

(3) the paste of face bricks should be full, but if the mortar is excessive, the face bricks are not easy to paste flat; If you knock too much, it will cause the slurry to concentrate on the bottom of the face brick or overflow, and form an empty drum after collecting the water, especially when sticking face bricks at the crenels and external corners, you should pay more attention to it, otherwise it is easy to produce uneven and empty drums at the external corners, resulting in the scattered face bricks

(4) in the process of pasting face bricks, it is advisable to survive at one time and not move, especially after the mortar is collected, it is easiest to cause hollowing. Generally, 1:0.2:2 dissimilated mortar can be used to paste mortar, and the common ratio is accurate. In the process of using mortar, do not mix water and ash casually

(5) make joint pointing. 1:1 cement mortar shall be used for jointing and sand through the window screen; Stop in two times. For the first time, point the joint with ordinary cement mortar, and for the second time, prepare colored cement mortar according to the color required by the design, and make a concave joint with a depth of about 3mm into the face brick. The joints of adjacent face bricks without joints shall be wiped with cement slurry of the same color as the face bricks. When wiping the joints, the residual slurry on the split face bricks must be cut off in time without leaving traces

2. The dividing joint is uneven, and the wall surface is uneven

1. Notice analysis

(1) before construction, the size of the drawing is not followed, the actual environment of layout construction is checked, and brick dividing and large-scale sample drawings are stopped

(2) the setting out of each part is not enough, and the control points are less

(3) the quality of face bricks is poor, the specification and size error is large, the bricks are not strictly selected in the construction, and the addition operation is improper, resulting in uneven dividing joints and uneven walls

2. Prevention and control measures

(1) before construction, verify the actual error environment of the layout according to the size of the design drawing, determine the paving thickness of face bricks and the module of brick arrangement, and draw a large-scale construction sample map. It is generally required that the horizontal joint should be level with the revolving face and the windowsill, and the external corner window should be made of whole bricks vertically. For example, the checker should be divided evenly by the whole block, and it is sure that the seams are large or small, and the dividing strips and leather poles should be drawn. According to the size of the large-scale sample drawing, the middle line, horizontal dividing line and vertical line of internal and external corners shall be measured in advance for each window core wall and brick stack, and the parts with large errors that are not suitable for the requirements shall be chiseled and repaired in advance as the basis for installing the window frame, making the windowsill, waist line, etc., so as to prevent uneven dividing joints and untidy brick arrangement at these parts when veneering bricks

(2) after the base course is bottomed, use dissimilated mortar to stick it in front of the face brick to make ash cake. The external wall should be hung with lines, and the internal and external corners should be hung straight on both sides. The bonding layer of ash cake should not be less than 10mm, and the spacing should not be greater than 1.5m. And snap several degree lines from top to bottom on the base ash according to the leather pole, and snap a vertical line at the window as a mark for tiling

(3) during the operation of paving face bricks, the upper mouth of the face bricks should be kept straight. After pasting a piece of bricks, the upper mouth ash should be scraped flat, and the uneven parts should be leveled with small wood chips or bamboo sticks, and then the dividing strips should be placed before pasting the second piece of bricks. The vertical joint shall be subject to the snapping line of the base mortar, which shall be checked at any time. After paving, the mortar at the vertical joint shall be cleaned at any time

(4) improve the selection of predecessors before using face bricks. Those with inclined appearance, missing corners, falling edges, warping, cracking and uneven color should be picked out, and the same size that needs to be regularly cleared should be classified into large, medium and small by using a sheathing board, and they should be used separately in different parts; Some shortcomings can not be used, because the quality of the face bricks makes the seams of the tiles not straight, the grids uneven and the colors uneven

3. Wall pollution

1. Notice analysis

the storage of split tiles and the protection of finished products after the wall is finished are not good; The mortar was not eliminated in time during the construction operation, resulting in wall pollution

2. Prevention measures

(1) from the beginning of tiling, it is not allowed to pour dirty water and garbage from the scaffold and outside. The operating staff should strictly ensure that the work is finished smoothly. The jointing of face bricks shall be stopped from top to bottom; When dismantling the scaffold, pay attention not to damage the wall

(2) face bricks packed with straw rope or colored paper should be protected from rain or moisture during transportation and storage

(3) after the completion of the face brick wall, if it is tarnished by mortar, cement slurry water, etc., and it is not easy to wash it with clean water, it can be washed with 10% dilute hydrochloric acid solution. Hydrochloric acid and calcium hydroxide at the mouth of the cement slurry can produce a chemical reaction, and become calcium chloride which is very soluble in water and has a low strength. The tarnished wall is easier to wash and clean. When washing, it should be from top to bottom, and then wash with clean water, otherwise the surface is easy to turn yellow

4. Whitening pollution

1. Notice analysis

(1) the primary cause of whitening pollution is calcium carbonate. The previous data of ordinary facing bricks are cement mortar (or mixed with a small amount of glue). During the hydration and hardening process, the cement mortar reacts with natural calcium hydroxide and other alkaline aqueous solutions, and roughly precipitates from the seams or facing bricks. Under the influence of carbon dioxide in the air, Peking Opera becomes water-insoluble and tolerant calcium carbonate. In addition, after the mortar hardens, it is immersed in rain water from the joints and other places, and the rain water will melt the water-soluble components in the mortar, and then precipitate from the face bricks or joints. When the precipitates are exhausted for many years and gradually expand, it will form a very beautiful whitening scene

(2) some face bricks have high water absorption. For example, when porous ceramic face bricks are used, lime water will be unfairly separated from the joint, and will be roughly separated out through the pores of the face bricks, becoming non melting materials, showing that all the face bricks are white. Because it is the whitening precipitated from the pores of the face brick, it is difficult to remove the whitening material (roughly, it will precipitate after removing the left behind)

2. Prevention measures

(1) do a good job in jointing, and change the nature of the jointing data, such as adding some aggregates, or appropriate polymers with waterproof properties, such as metal soaps, etc

(2) treat the joint with liquid waterproof agent to reduce the water permeability. In this way, although the waterproof agent can only penetrate mm from the hardened jointing data, it has a good result in preventing the infiltration of external rainwater

(3) stop fire prevention treatment for ceramic tiles. In order to reduce the water permeability of ceramic tiles and make the whitening pollutants not easily adhere to the outline of tiles, waterproof agents can be used to treat tiles

glazed tiles (also known as ceramic tiles, ceramic tiles and glazed clay tiles) are decorative

glazed tiles, which are glazed sheet-shaped fine pottery construction materials, and are mainly used for the internal walls and surfaces of buildings, as well as for pasting countertops, etc. Because of the material and construction, there are often common quality problems such as discoloration, pollution, hollowing, scattering, uneven joints, uneven joint width and rough cracks

1. Discoloration pollution

mainly shows whiteness reduction, yellowing, blooming, ochre and blackening

1. Notice analysis

(1) the back of glazed tiles is an unglazed body. If the water absorption is large and the texture is loose, various colors melted in the liquid gradually penetrate and disperse into the depth of the body until they are reflected from the front

(2) the body of glazed tiles in China is mostly white, and the glaze surface is transparent or translucent milky white glaze. The thickness of glaze before glazing is about 0.5mm, and the emulsion turbidity is lack, and the finishing ability is low

(3) the glazed tile is loose in texture and impervious to soaking before construction. When pasting, the slurry or dry water in the mortar seeps into the brick from the back of the glazed tile and gradually reacts from the transparent glaze, resulting in the discoloration of the glazed tile

2. Prevention measures

(1) when producing glazed tiles, appropriately increase the glaze thickness. If the glaze thickness is greater than 1mm, the result of color blocking is good. In addition, improve the compactness of glazed tile body, reduce water absorption, increase emulsion turbidity, etc

(2) during the construction process, soak the glazed tiles, use dry water, paste the mortar of glazed tiles, and stop mixing with clean raw materials; The paste should be dense, the brick joints should be well caulked, and the brick surface should be scrubbed and cleaned in time

(3) glazed tiles must be soaked thoroughly before pasting, and hidden injuries should be picked out. Try to use mortar with good workability and water retention. Do not knock the brick surface hard during operation to prevent hidden injuries, and scrub the mortar on the brick surface at any time

2. Empty and scattered

1. Notice analysis

(1) the base course is not handled well, the wall is wet and impermeable, and the mortar drops water too fast, resulting in low adhesion between glazed tiles and mortar

(2) the glazed tiles are lack of soaking, and the mortar is dehydrated at the initial stage of formation; The soaked bricks are pasted before drying, and the floating water makes the bricks float and fall

(3) improper operation, insufficient mortar, uneven thickness and uneven force

(4) the mortar has been drained, and then stop correcting and moving the pasted glazed tiles

(5) the glazed tile itself has hidden damage, which was not found in advance, and the caulking is not dense or missing

2. Prevention and control measures

(1) the base course shall be cleaned, roughly repaired and leveled, the concave places shall be made up by times, and the wall shall be watered and soaked

(2) the glazed tiles must be washed and cleaned before use, soaked in water until the glazed tiles do not emit bubbles, and many of them take out for 2h, and then roughly dry

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