In modern residential roof construction, the most used is slope roof construction, mainly because the shape of slope roof is not limited with one, and there are bright colors, and the slope roof has strong heat insulation.
Therefore, it is used more often in residential construction. It can be contrasted with the traditional flat roof construction, which is difficult to construct, and also has long leakage because the roof is inclined and difficult to compact, and also not easy to vibrate. In order to improve the quality of slope roof construction, we have to control the quality of the structure, and this article analyzes the slope roof construction technology combined with the specific project.
1 Project Overview
The slope of the roof of this project is large, and there are three kinds of slopes, namely 30°, 52° and 62°. In addition, there are tiger windows at the bottom of the sloping slab, and the structure is more complicated, with more detailed nodes, which makes the construction more difficult. In order to ensure that the roof shape is consistent with the design effect, the construction of the roof must strictly control the elevation of each detail such as roof slab and beam. During construction, special attention should be paid to the plan position and elevation of beam and slab nodes, as well as to the control of concrete pouring quality of cast-in-place slope roofs.
2 Technical points of slope roof construction
According to the actual characteristics of the project, the roof panel construction is determined according to the load of the formwork, the self-weight of the formwork and the bracket for the steel pipe full hall scaffolding, the vertical and horizontal spacing of the uprights is 800m, the steel pipe stands at the crossroads of the inner and outer horizontal flutes; the two-way horizontal rods are arranged between the uprights, the horizontal rod step distance is 1.5m, a horizontal rod is added along the slope of the roof in the direction of the bottom mold of the cast-in-place roof panel, and a scissor brace is set at the outer edge and the central axis. The scissor brace is set up at the outer edge and the center axis, so that the support system forms a tic-tac-toe structure.
And three horizontal shear braces are set at the top, middle and bottom. The spacing between supporting rods and internal and external horizontal flutes at the main beam of the top plate should be encrypted, and the middle of the bottom plate of the beam should be arched by 0.3%. The bottom diagonal brace of the beam shall be added, the steel pipe fasteners, the intersection of the horizontal flute and the vertical bar shall be double fasteners, and the square column shall be combined with nine plywood wooden moulds, hooped with steel pipes and rolled heads, and then supported.
2.2 Steel reinforcement works
The sampling of various steel materials is done before the steel material is imported, and after it is imported, according to the information requirements, various test data meet the specification requirements before it can be used in the project. As the length of the steel bars of the roof panel is not regular and the bending and demolition is more, therefore, the steel bars in each turn should be finished in the processing shed with cold bending machine according to the design angle to ensure the section size of its structure at the turn. The slope of the slope roof is large, in order to ensure the convenient operation of the reinforcement tying, a steel pipe picket is built on the top of the slope plate to ensure the convenient operation on the slope plate. The longitudinal and transverse bars on the slab surface should be drawn first and tied afterwards to ensure uniform spacing.
2.3 Concrete works
Due to the large slope of the roof, the slump of concrete should not be too small or too large. If the slump is too large, the concrete will not be easily formed, and the flow will occur when it is slightly pounded, and the pouring thickness cannot be controlled; if the slump is too small, although it is easy to be formed, it is difficult to lay the concrete, and the pounding cannot be fully compacted, which will easily cause honeycomb and pockmarked surface and cause quality defects. According to the calculated elevation and positioning size of each node, a 300mm long short steel head is used to weld a small upright rod in the corresponding part and mark it well with red paint or tape on it.
After the concrete is fabricated and leveled, remove the reinforcement head and seal the small hole left before the light is collected. Note that the reinforcement head should not be welded too tightly so that it cannot be removed. Roofing concrete is poured along the roof with the ridge as the dividing line, all around at the same time. The first step is to pour the concrete around the eaves of the edge first, in a clockwise direction in a circular interlocking circle. After the gable is poured, the concrete is poured clockwise in three layers from the slope of the roof panel at the outer ring line of the ridge, and the concrete is crossed before the initial concrete is poured, and then the second ring is poured again according to the route of the ring line, gradually approaching the ridge in turn, and finally completing the closing to complete the construction of the whole roof concrete.
2.4 Construction process of slope roof building
2.4.1 Construction of thick extruded polystyrene sheet
There are two general methods when laying insulation boards: one is dry laying; the other is bonding. And before laying, to consider a variety of factors, such as the specific situation of the roof, the direction of the roof and the specific slope, etc., in addition to consider the insulation board specifications. And also reasonable arrangement of insulation board.
If the edge of the board is beyond the specified position, then the excess part should be cut off. When laying, pay attention to the order of laying, to the laying process of the board reasonable plan, in laying can not be arbitrary cutting. In order to make the plate flat and straight, you need to lay it with the help of pulling lines or flat bullet lines. When the panels are laid, they should be smooth and dense, and the height of the two adjacent panels should be consistent. If the local, especially the corners of the location can not be completely paved, then you can cut according to the specific situation, and then use the broken pieces of inlay.
In the time of inlay, you need to first choose the waste edging, if the edging is not suitable in the choice of other materials. The same material should be used for the joints.
2.4.2 Fine stone concrete protection layer
Pre-embedded long wooden strips in the residence, the length of which should be determined according to the slope of the roof, and the long wooden strips generally used are made of pine wood. On the surface of the wooden strips, a layer of waste machine oil is applied. The strip is divided into two parts, the top part is 20mm and the bottom part is 10mm, the shape is wide at the top and narrow at the bottom, and the height of the strip is the same as the height of the mortar layer in the building, so that the strip can be taken out after use.
In the design of the sloping roof reinforcement, a two-way reinforcing mesh is used, and the location of the reinforcing mesh should be in the upper part of the protective layer of the roof, and the reinforcing mesh should be matted with blocks so that it can control the cracks. It is important to note that the reinforcement mesh is not continuous and is broken at the location of the parting joints.
The concrete should be configured in the laboratory and then constructed grid by grid. During the construction, it should be constructed from the far position first, and only after the construction in the far position is finished, the construction in the near position should be started, and it is constructed in the low position first, and after the end of the construction in the high position.
When pouring concrete, it is also necessary to spread out and scrape the slab with the height of the slab as a reference. Vibrate the slab with a plate vibrator and work the vibrator back and forth in a cross pattern. Work until mortar appears on the surface. Then use a wooden trowel to smooth the surface, the bottom of the building’s daughter wall, to be in a circular shape, when the concrete has just set, to immediately pull out the grid plate, while using the iron trowel to smoothen the surface of the concrete, check the defective places, to ensure that the surface is neat, before the concrete is completely set, start the third calendering, after the concrete has set, start to pour water on the surface maintenance, usually for the concrete maintenance of The concrete is usually maintained for more than 7 days.
After the concrete has been cured, flush the slit joints and let them dry. The sloped roofs have the same slit joints and start cleaning them after they are dry.
The slope roof is used in residential buildings with its beautiful shape, flexible combination and good drainage, heat insulation and thermal performance, but the rise of slope roofing also brings certain influence and hidden danger to the quality of roofing construction, therefore, the construction technology and method of slope roofing should be emphasized in the construction, emphasizing human factors, and the key parts and key processes should be strictly controlled, and the problems that appear in the construction should be analyzed and solved in time. problems and solve them, in order to meet the design requirements of construction specifications.