With the transformation of the form of architectural development in China, the concept of building a city is not only the pursuit of modernization, but also pays more attention to green, environmental protection, humanities, wisdom and livability. Prefabricated buildings have the characteristics of green construction and environmental protection and efficiency. Therefore, comprehensively promoting the development of prefabricated buildings has become the top priority of the construction industry.
As China's prefabricated buildings gradually enter the development stage of large-scale and main industry, what should construction enterprises do to continue to promote the development of prefabricated buildings in the future?
For enterprises, in addition to continuously absorbing foreign talents, it is also necessary to set up assembly related institutions within the enterprise, formulate long-term plans conducive to the training and development of assembly construction talents, constantly cultivate their own professional talent team suitable for the development of assembly construction, and speed up the construction of professional assembly construction technical workers, so as to occupy a favorable competitive position in the market.
Combine BIM with prefabricated buildings, comprehensively detect the collision between pipelines and civil engineering through BIM software, and provide it to professional designers for adjustment. At the same time, chip management technology (RFID) or two-dimensional code technology are used for information management in the whole process of component production, transportation, installation and acceptance, so as to continuously promote the application of BIM Technology in the planning, survey, design, production, construction, decoration The integrated application of the whole process of operation and maintenance can realize the whole life cycle data sharing and information management of engineering construction projects.
Strengthen the research and development of prefabricated building technology system, key technologies and supporting parts and components, promote the integrated design of prefabricated buildings, strengthen the overall planning of the production, installation and construction, decoration and other links of parts and components in prefabricated building design, master the new technologies, new products and new processes of prefabricated buildings, and constantly master the processes of hoisting, stacking, placement, support and protection. At the same time, the whole process quality monitoring and supervision system of prefabricated buildings shall be formed to conduct comprehensive quality monitoring on the assembly, inspection and acceptance of materials, components and key nodes, so as to effectively improve the quality level of engineering design and construction.
Compared with traditional cast-in-place buildings, prefabricated buildings can save about 50% of water, 80% of wood, more than 70% of construction waste, and reduce construction dust and noise pollution. In practical projects, green building materials such as environmental friendly wood composite, metal composite, high-quality chemical building materials and new building ceramics should be used as much as possible, combined with green buildings and ultra-low energy consumption buildings, and the integrated application of renewable energy such as solar photothermal photovoltaic, ground source heat pump and air source heat pump with prefabricated buildings should be increased, so as to improve the green degree of prefabricated buildings.
In addition, what points should construction enterprises pay attention to in the actual project?
Prefabricated wooden structure building
Fabricated steel structure building
Prefabricated concrete structure building
Inspection of fabricated wooden structure
(the article comes from the Internet, and the copyright belongs to the author. If it infringes, please contact to delete it)
1. Master the key points of deepening design
(1) The fabrication details of prefabricated components shall be prepared according to the reservation and embedding requirements of various disciplines and production and construction. In case of any conflict in the detailed drawing, the improvement shall be pointed out in time, so that the prefabricated component design can be modified in time.
(2) Check the details of prefabricated components to ensure that they meet the specification requirements and installation requirements. The construction party shall understand the relevant national standards and specifications of prefabricated components, and check whether the content and depth of the detailed drawing of prefabricated components meet the requirements of prefabricated components production, quantity statistics and installation construction.
2. Complete the detailed design content
(1) Practice of exterior wall decoration. During the detailed design of exterior wall decoration, attention shall be paid to the layout details of face brick, decorative concrete and stone, and the type and amount of materials shall meet the design requirements. At the same time, the stone procurement shall meet the requirements of aggregate strength and beautiful finish.
(2) Energy saving and thermal insulation structure of exterior wall. The thermal insulation structure shall meet the requirements of building functions. Pay attention to the selection of thermal insulation materials and connectors to ensure that the layout details are accurate. At the same time, the design performance shall be checked and the design calculation verification process shall be completed.
3. Attention shall be paid to the production of prefabricated components
(1) Production plan. The construction party shall timely participate in the design and adjustment of the production plan of prefabricated components according to the requirements of the drawings to ensure the steady operation of component production.
(2) Mold scheme. The construction party shall ensure that the drawing design meets the construction needs, cooperate to check whether there are problems in the production of the mold scheme according to the drawings, and put forward modification opinions as soon as possible.
(3) Personnel organization. Arrange special personnel to control the quality of component fabrication to ensure that the strength meets the standard, the size is appropriate and the appearance is appropriate; The specially assigned person shall be responsible for communicating with the component factory on behalf of the construction party, feeding back the production situation in time, and conveying the construction demand for components.
(4) Technical quality control measures. The component quality has a great impact on the later assembly and installation construction, and attention should be paid to timely communication with the component manufacturer. The component strength shall be tested in time, and it shall be redone in time if it does not meet the installation requirements; If the size is too different from the actual requirements, the manufacturer shall also be contacted in time to correct the deviation.
(5) Storage and transportation plan. Arriving at any time and reducing the transportation distance are the powerful guarantee to ensure the saving of land for prefabricated installation and construction.
1. Store
(1) Wooden components shall be stored in a well ventilated warehouse or in a rain proof and well ventilated covered place. The components stacked on the construction site should be stacked according to the installation sequence. The stacking should be arranged in the area within the working range of the crane and not affected by the construction of other processes.
(2) Corresponding measures shall be taken to prevent component deformation when the stack is placed horizontally. During overlapping stacking, the cushion blocks between components of each layer shall be aligned up and down, and the number of stacking layers shall be determined according to the bearing capacity of components and cushion blocks.
(3) When stacking against the frame, the inclination angle between the frame and the ground should be greater than 80 °.
(4) When stacking curve components, corresponding protective measures shall be taken according to the component shape.
2. Installation
(1) When temporary support is adopted for component installation, the distance between the support point of precast column or wall and the bottom shall not be greater than 2 / 3 of the height of column or wall, and shall not be less than 1 / 2 of the height of column or wall.
(2) Vertical component installation. Before installing the bottom layer components, the base layer elevation shall be compounded, and corresponding moisture-proof measures, such as moisture-proof pad, shall be taken; Before installing other layer components, the axis position and elevation of the installed components shall be compounded.
(3) Horizontal component installation. Two point hoisting should be adopted for the hoisting of rod components, and multi-point hoisting can be adopted for components with large length; The deformation and out of plane stability of slender components during hoisting shall be rechecked.
1. Store
The fire prevention capacity of steel structure is very poor and is greatly affected by temperature. When the steel structure is heated between 100 ~ 250 ℃, the tensile strength of the steel structure decreases and the plasticity increases with the increase of temperature; When the temperature reaches about 250 ℃, the tensile strength of the steel structure increases slightly, but the plasticity continues to decrease, resulting in "blue brittleness"; When the temperature exceeds 250 ℃, the steel structure will appear "creep phenomenon"; When the temperature reaches 500 ℃, the strength of steel structure is very low, which is easy to cause production damage, economic loss and even casualties. Therefore, the thermal insulation and fire protection design of steel structure is extremely important, and the ambient temperature must also be paid attention to in storage.
2. Installation
(1) Prefabricated steel structure buildings can adopt information technology to carry out information-based collaborative management of the whole process of safety, quality, technology and construction progress. BIM Technology can be used for virtual construction of structural components, building components and equipment pipelines.
(2) During the installation of high-rise steel structure, the influence of vertical compression deformation on the structure shall be included, and measures such as pre adjusting the installation elevation and setting the rear connecting members shall be taken according to the structural characteristics and influence degree.
(3) The prefabricated exterior wall panel can be permanently fixed only after the axis, elevation and vertical dispatching are checked. When the strip is installed with double-layer wall panels, the joint of the inner and outer wall panels should be staggered.
(4) Key points for installation of keel partition system.
1) The keel along the top and along the ground shall be adopted at the top and bottom. There shall be vertical keel in the vertical direction, and there shall be reinforced keel at the door frame; There shall be cross bracing keel in the transverse direction.
2) The keel along the top and the keel along the ground shall be fixed according to the snapping position. The fixing method can be shooting nails, expansion bolts, etc., and the nail distance shall not be greater than 600mm.
3) The vertical keel near the wall and column can be fixed with the wall and column with shooting nails, expansion bolts or wood screws, and the nail distance shall not be greater than 900mm.
4) The vertical keel in the middle shall be set according to the width of the cover plate in grades of no more than 1 / 2 of the plate width plus the gap width (generally 5mm), the spacing shall not be greater than 600mm, and both ends shall be fixed with shooting nails. When the two partition walls are connected longitudinally and horizontally, the vertical keel at the junction part cannot be omitted.
5) The cross brace keel can be connected and fixed with support card, bracket and connector. If necessary, it can be fixed with pop rivets, but electric welding is not allowed. The spacing between cross bracing keels shall not be greater than 1200mm. Keel shall be set at the joint of cover panel.
1. Store
(1) Placement of stacked floors. The first laminated floor slab shall be placed on the H-shaped steel to ensure that the truss is perpendicular to the section steel, and the section steel is 500 ~ 800mm away from the side of the member. 4 pieces 100mm for interlayer × 100mm × 250mm square timber shall be separated, and the four square timber positions at the four corners shall be placed parallel to the section steel. The number of storage layers shall not exceed 8 and the height shall not exceed 1.5m.
(2) Special storage rack for wallboard cube. The wallboard shall be stored in a special cubic storage rack. When the width of the wallboard is less than 4m, the lower part of the wallboard shall be padded with 2 pieces of 100mm × 100mm × 250mm square timber, one square timber at 30mm away from the wall at both ends. When the width of the wallboard is greater than 4m or there is a doorway hole, three 100mm pads shall be placed at the lower part of the wallboard × 100mm × 250mm square timber, one square timber at 300mm from both ends of the wall and one at the center of gravity of the wall.
(3) Storage of stairs. The stairs shall be stored in the designated storage area, and the ground of the storage area shall be horizontal. The second and third steps at the left and right ends of the folding ladder shall be padded with 4 blocks of 100mm × 100mm × 500mm square timber, 250mm from the front and rear sides, to ensure that the horizontal projection of square timber between layers coincides, and the number of storage layers shall not exceed 6.
(4) Storage of beams. The first layer of beam shall be placed on the H-shaped steel to ensure that the length direction is perpendicular to the section steel. The section steel is 500 ~ 800mm away from the side of the member. If the length is too long, an H-shaped steel shall be placed at an interval of 4m in the middle, and two layers shall be stacked at most according to the length and weight of the member. 100mm for interlayer × 100mm × 500mm square timber shall be separated to ensure that the horizontal projection of square timber between layers coincides with H-shaped steel.
(5) Storage of columns. The first layer of columns shall be placed on the H-shaped steel to ensure that the length direction is vertical to the section steel. The section steel is 500~800mm away from the side of the member. If the length is too long, an H-shaped steel shall be placed at an interval of 4m in the middle, and the maximum three layers shall be stacked according to the length and weight of the member. Block for interlayer 100mm × 100mm × 500mm square timber shall be separated to ensure that the horizontal projection of the square timber between layers coincides with the H-section steel.
2. Installation
(1) Before the prefabricated components with reinforced sleeve grouting connection and reinforced slurry anchor lap connection are in place, the following contents shall be checked: 1) specification, position, quantity and depth of sleeve and reserved hole; 2) The specification, quantity, position and length of the connected reinforcement shall be cleaned when there are sundries in the sleeve and reserved opening; When the connecting reinforcement is inclined, it shall be straightened. The deviation of connecting reinforcement from the center line of sleeve or hole shall not exceed 5mm.
(2) When grout setting material is used at the bottom of multi-storey precast shear wall, its thickness should not be greater than 20mm.
(3) During grouting construction, the ambient temperature should not be lower than 5 ℃; When the connection temperature is lower than 10 ℃, take heating measures.
(4) When installing prefabricated bending members, the laying length of the end shall meet the design requirements. Grout or support cushion block shall be set between the end and the support member, and the thickness of grout or support cushion block shall not be greater than 20mm.
This item includes four items: general provisions, materials, components and connections. It is clear that the material testing items should include physical properties, chord static bending strength, elastic modulus and so on; The inspection items of components shall include dimensional deviation, deformation, crack, anti-corrosion and anti moth, living termite, etc; The connection inspection shall include bolt connection, tooth connection, tenon and mortise connection, embedded bar connection and metal connector connection.
Inspection of fabricated steel structure
This item includes four items: general provisions, materials, components and connections. It defines the material testing, including the mechanical properties of steel, welding materials and fasteners, the chemical composition of raw materials, the defects and damages of steel plates and fasteners, and the metallographic content of steel; Component inspection shall include component size, structure, deviation and deformation; The connection inspection shall include welding connection, bolt connection, rivet connection, etc.
Inspection of fabricated concrete structure
This item includes four items: general provisions, materials, components and connections. It defines the content of material testing, including concrete and reinforcement in prefabricated components entering the site, post cast concrete, reinforcement and connection materials for on-site construction; The deviation between the dimensions of the components and the structural defects after construction and installation shall be detected; The connection quality inspection between structural members shall include the position and size deviation of structural members, the quality of sleeve grouting and mortar anchor lap grouting, the quality of welding connection and bolt connection, the quality of grouting at the bottom of prefabricated shear wall, the quality of cast-in-situ concrete in the cavity of double-sided superimposed shear wall, etc.
Other system detection
(1) The detection of peripheral protection system includes general provisions, prefabricated external walls, external doors and windows, building curtain walls, roofs, etc.
(2) The inspection of equipment and pipeline system includes general provisions, water supply and drainage, heating, ventilation, air conditioning and gas, electricity and intelligence, etc.
(3) The inspection of interior system includes general regulations, interior part system, indoor environment, etc.
