First, the general situation of the project.
Located in Urumqi through the opening of Wanda Plaza 2 on the 7th floor is currently under construction to the 15th floor, due to the need to erect a material transportation channel, the construction elevator entrance beam concrete is now partially chiseled, and then open out the opening to facilitate the normal use of the construction elevator, after the completion of the construction in the floor, according to the design requirements to restore the concrete structure beam.
Second, the basis for compilation.
Urumqi Jingkai Wanda Plaza construction drawings;
Urumqi Jingkai Wanda Plaza 2 sales property construction elevator layout drawing;
Urumqi Jingkai Wanda Plaza construction organization design;
Technical Code for Temporary Electricity Safety on Construction Site" (JGJ46);
Technical Code for Safety of Building Demolition Engineering (JGJ147-2004);
Safety Technical Code for Fastener Steel Pipe Scaffolding for Building Construction JGJ130-2011;
Unified Standard for Acceptance of Construction Quality of Construction Projects GB50300-2013;
Code for Acceptance of Construction Quality of Concrete Structure Engineering GB50204-2012;
Code for Reinforcement Design of Concrete Structures GB50367-2006.
Third, the construction organization framework chart.
Fourth, the construction arrangement.
Due to the urgency of the on-site construction, it is now necessary to immediately dismantle the conflict location, and the construction time is set for late March 2015.
5. Construction preparation and resource allocation.
5.1. Preparation before the removal of the window beam.
Before the window beam is removed, clean up the garbage around the site, check the drawings, clarify the demolition and modification parts, and mark the corresponding positions.
Prepare for demolition construction, clarify the demolition plan, and make a technical disclosure of construction safety before demolition.
Do a good job of safety protection before demolition, and all the edge openings in the demolition area are closed by templates to prevent falling objects from injuring people during the demolition process.
Press on the power supply: the demolition is carried out manually with the air pick, and before construction, a special distribution box is set up in the demolition area to be responsible for the dismantling of the electricity in the area.
The electricity used for demolition must meet the requirements for temporary construction electricity on site, and the corresponding temporary electricity protection shall be done.
Equipped with sufficient construction tools and materials, according to the progress requirements of the project, the main tools and materials that need to be equipped for the demolition of the wall are:
Table 1: Schedule of the main machinery for the removal of window beams.
Table 2: Schedule of main materials used in structural construction.
Table 3: Personnel schedule.
The demolition is carried out by a team with professional construction qualifications, and the number of demolition personnel and equipment meets the requirements of the construction schedule, and is deployed as needed.
Sixth, construction methods and process requirements.
6.1. Removal and method of window beam.
According to the drawing design, the cross-sectional size of the window beam that needs to be removed is 200*1500, and the upper reverse is 1020mm, and when dismantling, the height of the upper reverse needs to be chiseled out to ensure the erection of the construction elevator entrance platform. The transverse chisel length of the window beam here is 3550mm, and the longitudinal chisel height is 1020mm.
Turn on the power supply, connect the ventilation pickaxe and air compressor to break the concrete, and after the large-area concrete is broken, use a hammer, electric drill, etc. to remove the corner concrete reinforcement.
After the concrete removal is completed, the main reinforcement, waist reinforcement and stirrups of the window beam need to be cut, the concrete is broken according to the boundary of the junction of the beam and the wall, when the cutting of the reinforcement, the length of the main reinforcement of the beam, the waist reinforcement, stirrups and the like is reserved for 10d, and the adjacent reinforcement needs to be staggered with each other for 35d when cutting.
6.2. The restoration of the construction elevator after the use is completed.
After the use of the construction elevator on the 7th floor of the sales property is completed, the window beams at the entrance need to be restored by pouring concrete.
6.2.1. Steel bar welding:
When the rebar is cut, the rebar head of sufficient length has been reserved, and when the window beam is restored, the design requirements are used to weld the rebar on both sides, and the welding length is 5d.
6.2.2. Concrete pouring:
After the reinforcement binding is completed, the supervisor is notified to carry out concealed acceptance, and after the supervision acceptance is qualified, the window beam is sealed and poured. Before pouring, the concrete joint is brushed with plain cement slurry, and a grade of micro-expanded concrete is used for pouring than the original design.
6.2.3. Removal and transportation of garbage.
After the removal of the window beams, the garbage that exists is manually removed by a trolley and transported to the ground by a construction elevator, and then transported to the garbage dumping place by a trolley, and then transported away in a unified manner.
7. Quality standards and assurance measures.
7.1. The quality control measures of the construction process are detailed in Table 4.
Table 4: Quality control measures for construction processes.
7.2. Quality control measures for construction phases.
The construction is mainly divided into three stages, and through these three stages, the construction of each sub-project is effectively phased quality control. The quality control of the construction phases is shown in Table 5.
Table 5: Quality control measures for the construction process.
8. Quality control measures.
According to the long-term accumulated construction experience, targeted prevention and control measures are formulated for common quality problems.
8.1 Formwork engineering.
8.1.1. Preventive measures for template deformation.
1) Add the tie bolt according to the plan, and do a good job of in-mold jacking;
2) Strengthen the vertical support system of the load-bearing formwork, and the tie rod shall not be reduced at will;
8.1.2. The release agent is not applied to meet the requirements, and the precautions are taken.
1) Clean up the residual ash immediately after removing the mold, and then paint after cleaning
2) Water-based release agent to prevent oil from polluting steel bars;
8.1.3. Precautionary measures for in-mold cleaning.
1) The middle part of the beam mold is provided with a cleaning port;
2) Clean it with an air compressor before clamping.
8.1.4. Other support error prevention measures.
1) The top brace of the formwork shall not be spot welded on the main reinforcement at will;
8.2 Reinforcement works.
8.2.1. Material inspection and storage precautions.
1) The data clerk and the material clerk strictly control the material of the incoming steel bar;
2) Carefully check whether the incoming steel bars can implement the mixed batch standard;
3) Resolutely exit the appearance of unqualified peeling phenomenon;
4) Do a good job of rainproof and drainage measures for the reinforcement site;
5) Prevent cold extrusion and compression of steel bars.
8.2.2. Preventive measures such as large steel bar processing, hooking, anchoring, etc.
1) Make a processing model to ensure the hook angle and anchorage length;
2) Carefully consider the relationship between the intersection of comprehensive spaces and do a good job of magnifying the sample.
8.2.3. Protective layer control.
1) Check whether the thickness of the mortar cushion is accurate, and properly cushion it according to the size of the slab area
2) When the reinforcement mesh may sink with the concrete pouring, measures should be taken to prevent the deviation of the protective layer.
8.2.4. Rebar deviation.
2) Pay attention to the pouring operation, try not to collide with the steel bar, and check it by a special person at any time during the pouring process, and correct it in time.
8.2.5. Exposed tendons.
1) The appropriate amount of mortar cushion block pad is reliable, and the erection of steel bar can be used to bury the cushion block with iron wire, tied to the outside of the steel reinforcement skeleton;
2) At the same time, in order to make the thickness of the protective layer accurate, the steel skeleton should be pulled to the template by iron wire, and the cushion block should be squeezed firmly
3) Strictly check the forming size of the steel bar;When the steel skeleton is tied outside the mold, its external dimensions should be controlled and the allowable deviation should not be exceeded.
8.2.6. Precautionary measures for rebar binding.
1) Set the position hoop to prevent the main reinforcement from running out of position
2) Play the line before binding the steel bar and check the deviation phenomenon
3) Adopt plastic clips, order goods from the manufacturer according to actual requirements;
4) Elasticize the position line of the steel bar to ensure that it is horizontal and vertical, and the spacing meets the regulations.
8.3. Concrete engineering.
8.3.1. Concrete should not be used as a precautionary measure for construction joints.
Before pouring concrete, carefully calculate the initial setting time, pouring route, speed and layering thickness to ensure continuous pouring of concrete.
8.3.2. Preventive measures for improper treatment of construction joints.
1) The loose concrete and floating slurry must be thoroughly cleaned until the stones are exposed
2) Before pouring concrete, put 5 10 cm with the same ratio of stone-free mortar;
3) The vertical seam can not only be set with steel wire mesh, resulting in vibration is not compact.
8.3.3. Root rot prevention measures.
1) Make a leveling layer at the root of the formwork, and plug the seam with a sponge strip;
2) before pouring the mortar with the same mix ratio 5 10 cm;
3) Increase the workability of concrete and control the water-cement ratio
4) Do a good job of template cleaning and wetting.
9. Finished product protection.
1) The gap of the template is filled with cement putty or transparent glue (wall panel surface).
2) When pouring concrete, a special person is set up to take care of the formwork to prevent the formwork from expanding.
3) Before the concrete demoulding is dismantled, the application form for demoulding must be filled in according to the procedure, and the technical person in charge can only be dismantled after the concrete strength test report is approved and signed according to the same conditions.
4) When the formwork is dismantled, the action should be light to prevent the concrete from being bumped, especially the yin and yang corners.
5) The construction waste in the building should be cleared at the end of the building to ensure cleanliness and hygiene.
10. Safety and environmental protection measures.
1) During rectification, inspect the edge hole in the area and do a good job of safety protection for the edge hole. All openings are closed by 18 thick multi-layer formwork, and when the formwork is closed, 50 100 wooden squares are used as ribs, and the spacing is 200mm.
2) Do a good job of dismantling the best protection of electricity to prevent mechanical equipment from leakage and injury. The power connection of electrical equipment such as rectification of electricity must be in accordance with the corresponding equipment instructions and specifications.
3) During the electric welding construction, the construction personnel must operate according to the equipment operation procedures and equipment instructions, and illegal operations are prohibited.
4) During the rectification process, non-construction personnel are prohibited from entering the 3m cordon outside the demolition area.
5) When dismantling, set up a full-time safety officer to stand next to the station and do a good job of on-site safety monitoring.
6) All construction personnel wear safety helmets, and air workers wear safety belts.
7) During the construction operation, all workers are not allowed to drink alcohol.
8) Before entering the site, we must carefully check whether all the construction equipment and machinery entering the site are in good condition, and deal with any problems in time.
9) Set up a full-time safety officer on site to engage in safety inspection, inspect safety, fire protection and public security, and deal with problems in a timely manner.
10) Set up command personnel, and use wireless walkie-talkies to contact and command operators at any time to ensure safe production.
11) Strengthen employee management and prevent the occurrence of fights, thefts and other violations and crimes on the construction site.
12) The construction site should be equipped with sufficient fire-fighting equipment, and designated personnel should be designated to maintain, manage and update regularly to ensure that it is complete and easy to use.
13) When welding and cutting operations, there must be a fire certificate, and the fire approval system is strictly implemented.