Explanation of super-high construction case of masonry operation?

The following is a case of super-high masonry construction brought by Zhong Da Consulting for your reference.

I. Overview of the Project

The studio is the ground floor with three floors locally, and the building height ranges from 20m to 25m. The structural forms are all frame structures, and the large-space roof adopts steel trusses.

The building height of each floor (including the height of scaffolding beam) varies from 3m to 8m. The main enclosure structure of the shed is built with sintered shale solid bricks, and the wall of the auxiliary room of the studio is built with autoclaved aerated concrete blocks.

Due to the ultra-high masonry operation of the main part of the studio, it is necessary to build an ultra-high operating frame, and the transportation operation efficiency of masonry materials with single-layer structure is seriously low, which makes the construction difficult. At the same time, from the perspective of construction quality, the design of sound insulation wall has strict requirements for sound insulation, high detection index, and few similar construction cases for reference, so masonry construction must be strictly controlled. The main overview of masonry engineering is as follows:

Table 2.2- 1 Overview of Masonry Works

1000,2000,3000m2 studio (straight room)

Second, the masonry structure construction method

1, pay-off

Before each layer and section of the wall is laid, the wall should be bricked, especially the retention of doors, windows and constructional columns, and the operators should be given safety technical disclosure. Before masonry construction, accurately set out the axis, sideline and control line of the wall according to the construction drawing and brick arrangement drawing.

2, planting steel bar

The concrete members of the infilled wall, such as Rachel reinforcement, constructional column, lintel, ring beam and coping, all adopt the technology of planting reinforcement. According to the setting-out of the wall, find out the location of the rebar planting hole and mark it. When drilling, use a drill with a diameter of 4mm larger than the designed reinforcement to form a hole. After the hole is formed, use a blower to clean the hole. The drilling depth of rebar planting is 15d(d is rebar diameter). See table 2- 1 for technical parameters. Then fill the hole with glue to ensure that the hole is full. Insert the steel bar into the hole by rotation, and do not disturb the steel bar within 24 hours. According to the requirements of the specification, reinforcement planting must be carried out on-site pull-out test, and the next working procedure can be carried out only after passing the test.

Table 2- 1 technical parameter list of rebar planting

3. Vertical measuring rod

At the corner and end of masonry, a number of skin poles are set. The number of bricks, the thickness of mortar joint, the size and elevation of doors and windows, precast concrete blocks, Rachel bars, ring beams and lintels are indicated on the skin poles. The number of leather poles is vertical and firm, and the elevation is consistent.

When laying the shale brick wall of the studio, a few plasters are pasted on the frame columns on both sides of the infilled wall, and the thickness of mortar joint is strictly controlled according to the ruler.

Step 4 arrange bricks

According to the block arrangement diagram, the block is cut into a certain length and marked in the wall line, and the first skin masonry is tested.

The shale brick wall is 240mm thick, and the method of brick by brick is adopted (as shown in Figure 4- 1). The upper and lower staggered joints are 1/2 bricks, the internal and external joints overlap, and there should be no vertical joints. The width of mortar joint of shale brick should be 10mm, and it should be controlled at 8- 12 mm. Due to the acoustic requirements of shale brick masonry room, the wall must be full of mortar masonry without gaps.

Figure 4- 1 shale brick 240 wall assembly method

When laying autoclaved aerated concrete blocks, the laying length should not be less than 1/3 of the block length, and the width of horizontal mortar joint and vertical mortar joint should not exceed15 mm. The pendulum blocks should be arranged according to the actual size of the wall section and the specifications of the block. If it is less than a whole block, it can be sawed to the required size, but it shall not be less than 1/3 blocks long. See Figure 4-2 for the layout of autoclaved aerated concrete blocks.

Figure 4-2 Schematic Diagram of Aerated Concrete Block Brick Arrangement

Step 5 pull the cable

According to the skin pole standing at the wall end or corner, lay the wall at both ends and draw a double line in the middle. When laying the intermediate block, control the mortar joint and elevation according to the alignment.

Fig. 5- 1π rod traction double-line schematic diagram

6, mortar mixing

This project adopts ready-mixed mortar according to the design requirements. Mortar is mixed by mechanical stirring. After mixing, put it into the ash storage device, and do not dump it on the ground at will. Mortar must have high adhesion, good workability and water retention. If the mortar oozes water, mix it again before laying. Mortar should be used when mixing. Cement mortar should be used within 3-4h. Overnight and floor mortar are strictly prohibited.

7, masonry

1) If there is backfill at the position of the first-floor infilled wall, concrete foundation is needed, as shown in Figure 7- 1.

Figure 7- 1 Foundation method under partition wall

2) Block arrangement: according to the block arrangement diagram, cut the blocks into certain lengths and mark them in the masonry line. The methods and requirements for arranging blocks are as follows:

A, block masonry, according to the engineering design and construction drawing, combined with the varieties and specifications of the block, draw the Pareto diagram of the masonry block, and arrange the block according to the diagram after verification.

B, sintered shale brick adopts brick-by-brick masonry method, with a wall thickness of 240 mm ... Aerated concrete block adopts transitional masonry method, with a wall thickness of 200 mm, and the vertical mortar joint between upper and lower skins is staggered 1/2 block length.

3) Block wetting: The sintered shale brick should be watered and moistened 1-2 days before the upper wall, and the relative moisture content is 60-70%. Aerated concrete blocks should be watered and wetted on the day of masonry to wash away floating dust.

4) When the aerated concrete block is laid by mortar laying method, the mortar laying length should not exceed 750 mm The sintered shale brick is laid by "three-in-one" masonry method, that is, one brick is shoveled and squeezed, and the mortar extruded from the wall is hung at will.

5) Block positioning and correction: masonry positioning should be far before near, down before up, outside before inside; At the beginning of each floor, start from the corner or positioning block; Hanging build by laying bricks or stones a skin, correction of a skin, pipi stay control masonry elevation and wall flatness.

6) When laying, the horizontal mortar joint and vertical mortar joint of shale brick shall be 10mm, but not less than 8mm and not more than12mm; ; Mortar plumpness requirement of mortar joint 100%. The horizontal and vertical mortar joint of aerated concrete block should not be greater than 15mm, and the mortar fullness of mortar joint should be 80% or higher.

7) Masonry walls shall be built at the same time, and no straight holes shall be left, and no feet, hands or eyes shall be left when laying sound insulation walls. The daily masonry height shall not exceed 1.5m (it shall not exceed 1.2m in rainy days).

8) When building the whole building in the corner and other parts, bite the oblique if at the temporary discontinuity, and the horizontal projection of the oblique if is not less than two-thirds of the height of the building. When picking up the if, clean it up and water it first.

9) C20 concrete precast blocks with the same thickness as the wall shall be set at every 150mm× 150mm on both sides of doors and windows, so as to fix doors and windows, as shown in Figure 7-2.

Figure 7-2 Schematic Diagram of Precast Blocks at Doors and Windows

10) wall masonry must be hung on both sides. When the masonry and Rachel are at the same height, the Rachel prepared in advance should be adjusted in place and completely pressed into the mortar joint, and the wire tied to Rachel should be thrown out of the wall and marked. There should be a certain gap between the infilled wall masonry and the bottom of the beam, which will be filled by oblique masonry after 14 days of masonry. In the wall, precast equilateral triangular concrete blocks are used at the top of the plug, and right-angled triangular blocks are used at both ends, which are laid at a 60-degree inclination from the middle to both sides. As shown in Figure 7-3, the blocks must be plugged, compacted and filled with mortar one by one.

Figure 7-3 Method of Filling the Top of Wall

8, Rachel, lintel, constructional column, ring beam.

1) Rachel reinforcement settings:

At the junction of masonry and concrete wall and column, Rachel reinforcement is set by planting reinforcement. Set 2C6 Rachel bar. The length of Rachel bar embedded in concrete shall not be less than 15d(d is the diameter of reinforcement), and it shall run through the wall or reach the edge of doors and windows. Wall Rachel reinforcement binding connection, lap length is 55d and not less than 400m, Rachel reinforcement exposed mortar protective layer thickness is not less than 15 mm ... Rachel reinforcement should be set every 500mm high.

The setting of Rachel reinforcement is shown in Figure 8- 1:

Figure 8- 1 Schematic diagram of Rachel

2) Setting of lintel, ring beam and capping beam:

A, lintel: reinforced concrete lintel is needed when there is no beam at the top of the hole of the wall, door and window, and lintel is also needed when the width of the reserved hole exceeds 400 mm ... The lintel reinforcement is planted and implanted into the wall column 15d(d is the diameter of reinforcement). See Figure 8-2 and Table 8- 1 for lintel specifications and reinforcement:

Figure 8-2 Schematic diagram of lintel specification reinforcement

Table 8- 1 lintel selection table

B. Ring beam (horizontal tie beam): When the height of the wall is more than 3.6m, a ring beam connected with the column and running through the whole length of the wall is set at half the height of the wall or at the elevation of the ceiling of doors and windows, and the concrete strength grade is C25；; The width of ring beam is the same as the thickness of infilled wall B, and the height of ring beam is 120mm. Steel bar φ 410 (put four corners), stirrup φ 6 @ 200. Longitudinal reinforcement shall be bound and overlapped, and all longitudinal reinforcement shall be overlapped in the same connection area. The lap length of reinforcement is 50d, and the thickness of reinforcement protective layer is not less than 20mm. Post-planting reinforcement is adopted for ring beam reinforcement, and the depth of planting reinforcement is 15d. See Figure 8-3 for ring beam setting.

Figure 8-3 Schematic diagram of constructional column and ring beam setting

C capping beam: C20 concrete capping beam with a height of 200mm is set on the windowsill, the width is wall thickness, and there are four φ 6 long steel bars and φ 6 @ 200 stirrups inside.

3) constructional column setting

A, the filler wall is provided with constructional columns. The cross section of constructional column is a×200mm, and a is the wall thickness; At the intersection of the walls, the cross-section size of the constructional column is a×a, and a is the thickness of the wall. See the following figure for reinforcement of masonry constructional column:

Figure 8-4 Schematic diagram of reinforcement of constructional column

B, constructional column up and down the floor within the scope of 600mm height, stirrup spacing encryption to φ 6 @ 100. The stirrup spacing within the overlapping range of constructional column shall not be greater than 100mm, and there shall be no less than 4 stirrups. Longitudinal reinforcement of constructional column shall be bound and lapped, and all longitudinal reinforcement can be lapped in the same connection area, and the lap length of reinforcement is 50d. After the constructional column reinforcement is bound, build a wall and build it layer by layer from bottom to top.

C, constructional column rebar is planted together with rebar, and the length of rebar embedded in concrete is not less than 15d(d is rebar diameter).

D, according to the requirements of specifications and drawings, when the length of the infilled wall is more than 5m or twice the height of the wall, constructional columns are set at intervals of 4000mm along the wall length in the middle of the wall. When the wingless wall at the end of the infilled wall forms the free end, the constructional column is set, and when the wall length of the door and window sleeve is less than or equal to 120mm, the constructional column is set. When the width of the openings of the doors and windows of the infilled wall is greater than 2. 1m, constructional columns shall be set, with the dimensions of wall thickness × 150mm and reinforcement of 4 φ 12.

E, attention should be paid to the construction of constructional column: first build a wall and then pour it, and the wall will be built into a horse tooth shape with a mouth of 60mm and a height of 250 mm ... Mayacha is set to "return first". Horse teeth if lien as shown in figure 8-8.

F, Ma Yacha side mouth should be messenger wire laying constructional column with double-sided tape, the thickness is not less than 5mm, and a bell mouth is set at the top of the constructional column template. When pouring concrete, 30 vibrating rods should be inserted into the column to vibrate, and vibration cannot be transmitted by vibrating templates. After concrete pouring, chisel away the support.

Figure 8-8 Schematic diagram of rubber limit of constructional column saddle

Fig. 8-9 Schematic diagram of structural column bell mouth

Figure 8- 10 Structural Column Layout Schematic Diagram

9, guide wall and threshold settings

C20 concrete anti-ribs with a height of 150mm (away from the building facing) are set at the bottom of the infilled wall of the indoor room with water, toilet, tube well and elevator shaft. High concrete threshold with a height of 300mm and a width of 100mm shall be set at the entrance of electrified rooms such as strong and weak current rooms and power distribution stations, which shall be flush with the wall endothelium. C20 plain concrete anti-sill is poured at the bottom of the external wall filler wall, which is 250mm above the ground. For the parts with waterproof requirements, after the concrete pouring is completed, the root of the wall should be painted in a figure of eight in time, and the masonry part within the height range of 300mm at the same time should be plastered and calendered to facilitate waterproof construction.

After the setting-out of the anti-sill position is determined, before the formwork is erected, the joint between the floor and the wall should be chiseled, and the concrete can be constructed only after it is qualified.

10, matters needing attention in masonry construction

1) Block yard must be flat and well drained. The stacking height shall not exceed 1.6m, and proper passages shall be maintained between stacks. And there should be rain protection measures. At the same time, to ensure that the age of aerated concrete block is not less than 28 d..

2) The sintered shale brick shall be watered and wetted one or two days in advance, and the aerated concrete block shall be watered and wetted to the masonry surface on the same day. Blocks should be cut from the oily surface, and there should be no chips on the cutting surface. Sawing wood blocks should use special tools, and it is not allowed to chop them with axes or tile knives at will. Regular pulleys should be used on both sides of the hole.

3) The position of Rachel reinforcement retained by masonry is consistent with the number of blocks. Rachel reinforcement is placed in mortar joint, and the embedding length is the length of the whole wall.

4) When there is no constructional column at the corner of the wall, the blocks will be split and staggered.

5) The mixed mortar is transported to the masonry site by the ash truck. Before the block is in place, the block is paved with a shovel and an ash spoon.

6) When laying the foundation, check whether the surface elevation is appropriate according to the bottom elevation of the skin pole. If the horizontal mortar joint of the first layer brick is greater than 20mm, it shall be leveled with fine stone concrete.

7) When repairing the temporary discontinuity in masonry construction, the joint surface must be cleaned, watered and moistened, and filled with mortar to keep the mortar joint straight.

8) The size of the reserved hole for installation shall be reserved according to the plan of the reserved hole for pipeline, and the lintel shall be set as required, and it shall be blocked after the subsequent installation is completed.

9) Block the reserved hole on the wall. After the installation of pipeline equipment, C20 expansive fine stone concrete is used to fill the reserved holes in the masonry wall.

10) The construction team should be equipped with skilled foreman and technicians with high political quality as the heads of masonry, testing and other processes, and carry out the responsibilities, formulate the responsibility system of rewards and punishments, strictly reward and punish, check and deal with them in time, resolutely rework the stabilized sand if it fails to meet the quality standards, and investigate the responsibilities of those responsible.

1 1) All blocks can be constructed only after passing the acceptance test, and the next working procedure can be constructed only after each working procedure is accepted by the supervisor.

1 1, sampling rules and methods of masonry mortar

I. Sampling regulations

(1) Take at least one set of test pieces for each layer of masonry mortar with the same mixture ratio.

(2) For each inspection lot and masonry mortar of various types and strength grades of masonry with no more than 250m3, each mixer shall sample at least once.

(3) The test size of cement mortar is 70.7mm×70.7mm×70.7mm, with a bottom. When the temperature is low at (20 5)℃, the time can be appropriately extended, but it shall not exceed two days and nights. The sample shall be immediately placed in a standard curing room with a temperature of (20 2)℃ and a relative humidity greater than 90%. During the curing period, the interval between specimens shall not be less than 10 mm ... After curing for 28d, pressure test shall be conducted.

B, autoclaved aerated concrete block the same variety, the same density grade, the same strength, with ten thousand pieces as a batch, the shortage is also counted as a batch.

C, the same variety, the same strength grade of sintered shale solid brick, with100000 pieces as a batch, the insufficient part is also counted as a batch.

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