What are the bricklaying methods?

The commonly used masonry method is Sanshun Ding Yi masonry method, which has good wall integrity. See the code for brick masonry for details.

5 brick masonry project

5. 1 General provisions

5. 1. 1 This chapter is applicable to masonry projects such as sintered ordinary bricks, sintered perforated bricks, autoclaved lime-sand bricks and fly ash bricks.

5. 1.2 Bricks used for drywall and column surfaces shall have neat edges and consistent colors.

Note: 5. 1.2 The bricks used on the surface of drywall and column should be blocks with neat edges and uniform colors according to the requirements of the appearance quality of masonry.

5. 1.3 In areas with frost heaving environment and conditions, porous bricks should not be used for masonry below the ground or below the moistureproof layer.

Note: 5. 1.3 Masonry under the ground or moistureproof layer is often in humid environment, and some are below the water level. Under the action of frost heaving, the durability of perforated brick masonry is greatly affected. In areas with freezing environment and conditions, it is not suitable to use perforated brick under the ground or in the moistureproof layer.

5. 1.4 When building brick masonry, the brick should be watered and wetted in advance 1~2d.

Note: 5. 1.4 Watering before brick masonry is a part of brick masonry construction technology, and the wetting process of brick has great influence on the construction quality of brick masonry. The comparative test shows that the appropriate moisture content can not only improve the bonding force between brick and mortar and the shear strength of masonry, but also keep the normal growth of mortar strength and improve the compressive strength of masonry. At the same time, the appropriate moisture content can also make the mortar maintain a certain paving fluidity on the operation surface, which is convenient for construction operation and conducive to ensuring the fullness of the mortar. These are very beneficial to ensure the construction quality and mechanical properties of masonry.

According to the comparative test of relevant scientific research units and the test of construction enterprises, the suitable water content value is put forward. The moisture content of sintered common brick and perforated brick should be 10%- 15%. The moisture content of lime-sand brick and fly ash brick should be 8%- 12%. The simple method to detect the moisture content of bricks on the spot is the broken brick method. When the melting water depth around the brick section is 15-20mm, it is regarded as the appropriate moisture content that meets the requirements.

5. 1.5 When the mortar masonry method is adopted in the bricklaying project, the mortar masonry length shall not exceed 750mm；; When the temperature exceeds 30℃ during construction, the slurry laying length shall not exceed 500mm.

Note: 5. 1.5 brick masonry should be built with mortar. When masonry is laid with mortar, the length of mortar has obvious influence on the shear strength of masonry. The test of Shaanxi Institute of Building Science Design and Research shows that when the temperature is 65438 05℃, the shear strength of masonry is 30% different, and masonry is done immediately after grouting and 3 minutes after grouting. When the construction temperature rises, the impact is greater.

5. 1.6 The top skin brick of each bearing wall with a thickness of 240 mm, as well as the floor elevation and brick masonry of the selected layer shall be built with whole bricks.

Note: 5. 1.6 From the perspective of ensuring the integrity, integrity and stress rationality of masonry, it is emphasized that the parts mentioned in this article should be built with whole bricks.

5. 1.7 The mortar joint of brick flat arch lintel should be wedged. The width of mortar joint at the bottom of lintel should not be less than 5 mm; The top of lintel should not be greater than15 mm. ..

Below the arch foot, it should be no less than 20mm into the wall, and the arch bottom should have 1% super arch.

Description: 5. 1.7 brick flat arch lintel is a special case of brick arch structure, which is a slightly rising arch structure. Considering its mechanical characteristics and construction technology, it is necessary to ensure the length of the arch foot protruding into the wall and the amount of arching at the arch bottom, and to maintain the wedge-shaped mortar joint shape.

5. 1.8 The formwork at the bottom of brick lintel can only be removed when the mortar strength of mortar joint is not less than 50% of the design strength.

Note: 5. 1.8 lintel bottom formwork is the load-bearing structure in the process of masonry. After the mortar reaches a certain strength, the masonry at the lintel can bear the load and the bottom die can be removed. Mortar strength is generally subject to actual strength.

5. 1.9 The holes of perforated brick shall be laid perpendicular to the compression surface.

Note: 5. 1.9 The holes of perforated brick are perpendicular to the compression surface, which can make the masonry have a larger effective compression area, which is beneficial for the mortar bonding layer to enter the holes of upper and lower bricks to produce the "pin key" effect and improve the shear strength and integrity of masonry.

5. 1. 10 The product age of autoclaved (convex) bricks laid during construction shall not be less than 28d.

Note: 5. 1. 10 lime sand brick and fly ash brick have larger early shrinkage value after leaving the kettle. If it is used on the wall at this time, it is easy to have obvious shrinkage cracks. Therefore, it is required that the parking time after leaving the kettle should not be less than 28 days, so that the early shrinkage value can be mostly completed during this period, which is an important technical measure to prevent the early cracking of the wall.

5. 1. 1 1 Vertical mortar joint shall be free from penetration, blind joint and false joint.

Note: 5. 1. 1 Plumpness of vertical mortar joint generally has little influence on compressive strength of masonry, but has obvious influence on shear strength of masonry. According to the research of Sichuan building science and the test results of Nanjing Xinning Brick and Tile Factory, it is concluded that the shear strength of masonry will be reduced by 40%-50% when the vertical joint mortar is not full or even completely mortar-free. In addition, transparent joints, blind joints and false joints will also have an adverse impact on the use function of the house. Therefore, the quality requirements of vertical mortar joint in masonry construction are stipulated accordingly.

5. 1. 12 When repairing temporary discontinuity in brick masonry construction, the joint surface must be cleaned, watered and wetted, and filled with mortar to keep the mortar joint straight.

Note: 5. 1. 12 The joints at the temporary breaks in brick masonry construction are themselves weak points. In order to ensure the integrity of masonry, the requirement of repair must be emphasized.

5.2 Master control project

5.2. 1 The strength grade of brick and mortar must meet the design requirements.

Sampling quantity: after the bricks from various manufacturers enter the site, 6,543.8+0.5 million pieces of sintered bricks, 50,000 pieces of perforated bricks, 6,543.8+0,000 pieces of lime-sand bricks and fly ash bricks are accepted as a batch, and the sampling quantity is 654.38+0 groups. The sampling quantity of mortar test block shall comply with the relevant provisions of Article 4.0. 12 of this specification.

Inspection method: check the test report of brick and mortar test block.

Note: 5.2. 1 The strength of brick and mortar meets the design requirements, which is the basis to ensure the mechanical properties of masonry and must be qualified.

The number of inspection lots for sintered common bricks shall be determined with reference to the number of basic inspection lots for masonry (250m3 masonry); The number of inspection lots for perforated bricks, lime-sand bricks and fly ash bricks is indeed determined according to product standards.

5.2.2 Mortar plumpness of horizontal mortar joint of masonry shall not be less than 80%.

Sampling quantity: each inspection lot should not be less than 5 sampling points.

Inspection method: Check the bonding trace area between brick bottom and mortar with grid. 3 bricks are detected at each place, and the average value is taken.

Note: 5.2.2 The stipulation that the plumpness of horizontal mortar joint is not less than 80% has been used for a long time. According to the research and test results of Sichuan building science, when the mortar plumpness of horizontal mortar joint reaches 73.6%, it can meet the compressive strength of masonry specified in design code. Masonry with special requirements refers to masonry with clear requirements for mortar fullness in design.

5.2.3 The corner and junction of brick masonry should be built at the same time, and it is forbidden to build the internal and external walls separately without reliable measures. For temporary breaks that can't be built at the same time and must be kept, they should be built into oblique forks, and the horizontal projection length of oblique forks should not be less than 2/3 of the height.

Sampling quantity: 20% for each inspection lot, and no less than 5.

Inspection method: observation and inspection.

5.2.4 For temporary breaks in areas with non-seismic fortification intensity of 6 and 7 degrees, if oblique gaps cannot be left, straight gaps can be left except at corners, but the straight gaps must be made into convex gaps. Stay straight if Rachel should be added, the number of Rachel reinforcement is per 120mm wall thickness 1 φ 6 Rachel reinforcement (2 φ 6 Rachel reinforcement are placed on 120mm wall thickness), and the spacing along the wall height should not exceed 500mm；; The embedding length is not less than 500mm from each side of the indwelling point and not less than1000mm; Areas with seismic fortification intensity of 6 degrees and 7 degrees; The ending should be 90? Hook (Figure 5.2.4).

Sampling quantity: 20% for each inspection lot, and no less than 5.

Inspection method: observation and ruler inspection.

Eligibility criteria: the retention is correct, the number and diameter of Rachel reinforcement are correct, the deviation of vertical spacing is less than 100mm, and the retention length basically meets the requirements.

Note: 5.2.3-5.2.4 The quality of masonry and jointing at the corner and junction of brick masonry is one of the keys to ensure the overall performance and seismic performance of brick masonry structure, which has been fully proved by the lessons of earthquake damage in Tangshan and other areas. According to the introduction of Shaanxi Building Science Research and Design Institute, the joint masonry at the same time has the best connection performance; Leave the second step if (oblique if); Leave straight if and Gallas knot reinforcement and then deal with it according to regulations; Keep it straight only if you don't add Rachel reinforcement. The ratio of the connection performance of the above different masonry and masonry forms is 1.00: 0.93: 0.85: 0.72.

For temporary breaks in areas with seismic design intensity of 6 and 7 degrees, straight joints are allowed, and Rachel bars are added according to regulations, which is slightly relaxed compared with the original Code for Construction and Acceptance of Masonry Engineering (GB50203-98). This is mainly based on the premise of ensuring the construction quality, the connection performance is limited compared with the diagonal connection, so it is feasible to allow the vertical connection to add Rachel bars in areas with low seismic design intensity.

According to the specifications and dimensions of brick, the length-width ratio of inclined brick masonry is generally 1: 2.

5.2.5 The allowable deviation of the position and verticality of brick masonry shall comply with the provisions in Table 5.2.5.

Table 5.2.5 Allowable deviation of position and verticality of brick masonry

Inspection method of allowable deviation (mm) of the project

1 axis position deviation 10 check with theodolite and ruler or check with other measuring instruments.

2 The verticality of each layer shall be checked with 2m support plate.

Total height ≤ 10m 10 shall be checked by theodolite, messenger wire, ruler or other measuring instruments.

〉 10m 20

Sampling quantity: check all load-bearing wall columns along the axis; Exterior wall verticality full height check Yang Angle, should not be less than 4, each layer of 20m check a place; Interior walls shall be drawn as per 10% of representative natural rooms, but there shall be no less than 3 rooms, each room shall have no less than 2 places and no less than 5 columns.

Note: 5.2.5 Axis position deviation and verticality of brick masonry are key testing items that affect structural mechanical properties and structural safety. Therefore, they are included in the main control items. The allowable deviation value and sampling quantity still follow the provisions of the original construction acceptance specifications and inspection and evaluation standards.

5.3 General projects

5.3. 1 Brick masonry shall be assembled correctly, with staggered joints up and down, internal and external masonry, and brick columns shall not adopt the core-wrapped masonry method.

Sampling quantity: sample one place for the external wall every 20m, 3-5m for each place, and not less than 3 places; According to the representative natural rooms, the interior wall of 10% should be drawn, and there should be no less than 3 rooms.

Inspection method: observation and inspection.

Qualification standard: There is no joint between drywall and window wall except meeting the requirements of this article; There should be no more than three joints with a length greater than or equal to 300mm in the mixed water wall and they should not be located on the same wall.

Note: 5.3. 1 This article is the basic requirement of masonry assembly method from the perspective of ensuring the integrity of masonry structure and benefiting the bearing capacity of the structure, which should be met in construction. "Straight seam" refers to the part where the overlapping length of the upper and lower tiles is less than 25mm.

5.3.2 Brick mortar joint should be horizontal, flat and vertical, with uniform thickness. The thickness of horizontal mortar joint should be 10mm, but not less than 8mm and not more than 12 mm.

Sampling quantity: every 20m of masonry laid by scaffolding is sampled 1 place.

Inspection method: Convert by measuring the height of 10 skin brick.

Note: 5.3.2 The mortar joint is horizontal and vertical, and its thickness is even, which is not only a requirement for the beauty of the masonry surface, especially for the drywall, but also conducive to the uniform force transmission of the masonry. In addition, the test shows that the thickness of mortar joint also affects the compressive strength of masonry. For ordinary brick masonry, compared with the standard horizontal mortar joint thickness 10mm, the compressive strength of masonry with horizontal mortar joint thickness 12mm is reduced by 5%; The compressive strength of masonry with 8mm horizontal mortar joint thickness is improved by 6%. For perforated brick masonry, the change range is greater. Therefore, it is stipulated that the thickness of horizontal mortar joint should not be less than 8mm or greater than 12mm, which is also the data that has been used all the time.

5.3.3 The allowable deviation of the general dimensions of brick masonry shall comply with the provisions in Table 5.3.3.

Table 5.3.3 Allowable deviation of general dimensions of brick masonry

Allowable deviation of the project

(mm) Sampling quantity of inspection method

1 top surface of foundation

And floor elevation+15. Check at least 5 places with a level and a ruler.

2 surface

Smooth and clear

For walls and columns, 65,438+00% representative natural rooms should be inspected with 2m guide rule and wedge feeler, but there should be no less than 3 rooms, and each room should be no less than 2 rooms.

Turbid water

Wall, column 8

3. Height and width of door and window openings

(Rear plug) 5 Check 10% inspection lot holes with a ruler, and there shall be no less than 5 holes.

4. The deviation between the upper and lower windows of the external wall is 20, and the bottom window shall prevail. Use theodolite or messenger wire to check 10% of the inspection lot, and there should be no less than 5 places.

5 horizontal mortar joint

The straightness of the 7-pull 10m line and ruler of the drywall shall be 10% of that of a representative natural room, but there shall be no less than 3 rooms, and no less than 2 places in each room.

Mixed water wall 10

6.20 messenger wire and ruler are used to check the sewing condition of drywall. The first leather brick on each floor shall prevail. There are 10% representative natural rooms, but there should be no less than 3 rooms, each with no less than 2 rooms.

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Note: 5.3.3 Although the general dimensional deviation of brick masonry listed in this article will not have an important impact on the mechanical properties and structural safety of the structure, it will have an impact on the construction quality, economy, simplicity, aesthetics and effective use area of the whole building, so the deviation should also be controlled in the construction.