I. Overview of the Project:

The quality problems in the construction of the main works of buildings A, B, C, D, E, G, E and H in the second area of Guibei, Dianjiang County, undertaken by our company, were raised during the acceptance of the intermediate structure on April 4th, 20xx. In view of these problems, our unit has formulated a special rectification plan:

Second, the bearing phenomenon:

Cracks appear at the internal corner of the wall where the second-floor axis 1/M of Building B intersects with axis 2.

Third, the reason analysis:

At the end of the brick masonry, leave a horse tooth if according to the specification requirements, and install wall reinforcement until the second floor concrete cracks.

Fourth, make a treatment plan:

1, clean the cracked mortar joint first, then rinse it with water, fully wet the wall with water 1d in advance, and then repair the joint with 1: 2 cement mortar and compact it.

2. Behind the brick wall of 1 axis, drill a hole with a diameter of 200MM at a height of 50 cm perpendicular to 1/M axis, and the length is more than 600CM. After cleaning, the horse teeth will be formed, washed with water, and the brick wall will be soaked with water. Two steel bars with a diameter of 8mm and a length of not less than 500 mm should be used. Both ends of the steel bars should be hooked at 90 degrees and put into the horse teeth.

4. Before plastering, steel wire mesh must be hung on both sides, and the material of the steel wire mesh is (low carbon steel wire welded mesh for plastering walls, plain weave, aperture 50*50MM, wire diameter 40 wires).

Verb (abbreviation for verb) Bearing phenomenon:

There are some defects in cast-in-place concrete, such as formwork, honeycomb, pitted surface and exposed reinforcement.

6. Cause analysis: Due to the tight construction period of brick-concrete structure and unequal operation skills of workers, the formwork of cast-in-place concrete members is loose and submitted, resulting in defects such as formwork submission, honeycomb, pits and exposed tendons in individual parts of cast-in-place concrete members.

Seven, formulate treatment plan:

1, the elastic line of concrete formwork application shall be flat, straight, concave and convex, vertical, and shall not exceed15 mm. ..

2. Eliminate dense concrete, honeycomb, pits and exposed concrete; Rinse with water and brush with plain cement slurry; Filling with C30 expansive fine stone concrete, vibrating and compacting;

3, timely maintenance as required.

Eight, load-bearing phenomenon: irregular shallow cracks appear on the surface of the sun window plate, criss-crossing, irregular, uneven, different lengths, incoherent.

Cause analysis: Cracks in cast-in-place reinforced concrete sun window panels are mainly caused by temperature deformation and shrinkage deformation of concrete. When the temperature and humidity of the environment change, concrete will produce temperature deformation and shrinkage deformation accordingly.

X. treatment plan:

1, smaller or shallower cracks can be left untreated.

2. Non-penetrating crack:

Chisel and flush the cement mortar on the crack surface along the length of the crack. The width of both sides of the crack is 15mm, and it is filled with epoxy cement.

3. Through the crack:

Cut a 30mm wide V-shaped groove along the seam, and surface washing will be clean. Use AE11modified epoxy resin liquid or structural adhesive with rebar planting to press and fill the joint, and then use carbon fiber cloth to strengthen the sunshine window. When using carbon fiber cloth, for a single crack, in addition to sticking along the seam, it needs to be stuck at intervals perpendicular to the seam direction; The redundant joints that cross each other should be pasted into a hash shape with the same spacing and width.

Xi。 Bearing phenomenon:

Brick masonry mortar is not full, joints are not dense, vertical flatness of brick masonry is poor, and some walls are displaced.

Twelve. Cause analysis:

1, brick masonry mortar is not full, if not dense; The main reasons are tight construction period, unequal technical skills of workers and inadequate management.

2. The vertical flatness of brick masonry is poor; Mainly because the bricks supplied by several brick factories are different in size and are not stacked in the factory.

3. The main reason for the displacement of some walls is that the construction period is tight. When the strength of the brick masonry sand pump can't reach the standard strength, the carpenter will hold the formwork, which will affect the brick masonry structure and lead to the displacement of some walls when pouring concrete.

Thirteen. Treatment plan:

1. If the mortar of brick masonry is not full and the joints are not dense, clean the loose joints first, rinse them with water, fully wet the wall with water 1d in advance, and fill the joints with cement mortar 1: 2.

2. The mortar of brick masonry is not full. If the wall is not dense, steel wire mesh must be hung on both sides before plastering (steel wire mesh material is special for low-carbon steel wire welding mesh for plastering wall, specification: plain grain aperture 50*50MM and wire diameter 40 wires).

3, brick masonry vertical flatness is poor, and the displacement of the wall in front of the fenshui column, leveling, fenshui thickness more than 2.5 cm wall should be hung with steel mesh construction.

The above quality problems must be rectified one by one in strict accordance with the construction specifications. After the rectification is qualified, it shall be reported to the project department and supervision department for secondary acceptance, and the next working procedure can be entered only after it is qualified.

Scheme 2: Liu Qing Xiyuan North and South Land Quality Inspection and Rectification Scheme.

I. Purpose of the compilation

On April 9th, 20xx, the quality supervision department attached great importance to some problems existing in the project quality of Liu Qing Xiyuan North-South Block, and immediately held a special meeting on this inspection, which rectified the problems found this time one by one, and formulated a targeted and effective rectification plan.

Second, the compilation basis

Liu Qing Xiyuan Construction Organization Design

Code for Acceptance of Construction Quality of Concrete Structure Engineering -GB50204-2002 Concrete Quality Control Standard-jgjt50164-2011

Code for welding and acceptance of steel bars JGJ 18-20xx

Guide to prevention and control of common quality diseases in Chuzhou city

Code for seismic design of buildings GB500 1 1-20xx

Code for Building Deformation Measurement JGJ8-2007

Construction Atlas11g1kloc-0/-1and related design documents.

Third, the existing problems:

1, the Guide for Prevention and Control of Common Quality Diseases of Residential Projects in Chuzhou City was not strictly implemented, and the special plan for prevention and control of common quality diseases was not targeted.

2. The top floor of Building15x has no report on the same condition test block and test block removal, but the formwork has been removed; The electroslag pressure welding joint has a burr, which is not well formed, so it is not treated.

3. The cracks in the seventh floor of15x building are serious, and the cast-in-place slab on the operation surface will be installed in less than two days, which is a hidden danger.

4. The post-cast strip is dismantled too early, which has hidden dangers of quality and safety.

5. Acceptance of individual types of steel bars is not in place when they enter the site. For example, HRB400 rebar with batch number 12 12028300 and diameter 12mm has no quality certificate.

6. The construction unit did not observe the settlement of the project.

7. The project has not gone through the construction permit formalities.

Fourth, the rectification measures:

1, the Guide for Prevention and Control of Common Quality Diseases of Residential Projects in Chuzhou City was not strictly implemented, and the special plan for prevention and control of common quality diseases was not targeted.

1. 1 remedial measures

As for the on-site 15x building, it was not strictly implemented in accordance with the relevant provisions of the "Guidelines for the Prevention and Control of Common Quality Defects in Residential Projects in Chuzhou City". The project immediately organized relevant technical personnel and management personnel to study the Guide to Prevention and Control of Common Quality Diseases in Chuzhou Residential Engineering again, strengthened internal management, and strictly followed the Guide to Prevention and Control of Common Diseases. In view of some problems existing in the site, the construction scheme for prevention and treatment of common diseases has been re-compiled.

2. The top floor of Building15x has no report on the same condition test block and test block removal, but the formwork has been removed; The electroslag pressure welding joint has a burr, which is not well formed, so it is not treated.

2. 1 Remedial measures

The curing age of five-story roof blocks with the same conditions should be the age corresponding to the cumulative daily average temperature of 600d, and the equivalent age should not be less than 14d or more than 60 d, and then a qualified testing center should be entrusted to the site to rebound the floor concrete with a rebound instrument, and the obtained results should be included in the evaluation of blocks with the same conditions; The project department attaches great importance to the removal of the floor formwork and does not remove the template test block. A qualified testing center has been entrusted to rebound the floor concrete on site with a rebound instrument. According to the calculation results, the strength of the formwork is 75% when it is removed, which strengthens the project management and prevents the recurrence of such problems. For the electroslag pressure welding joint, all the gaps, slag inclusion, uneven welding bracts, poor forming and so on. Use oxygen to cut the steel bars that exceed the specification requirements, and use a grinder to grind the cut steel bar head flat, and then weld it again;

3. The cracks in the seventh floor of15x building are serious, and the cast-in-place slab on the operation surface will be installed in less than two days, which is a hidden danger.

3. 1 Remedial and preventive measures

3. 1. 1. Wash the cracks with water, put the water and waterproofing agent into the bucket, then put the cement into the bucket, stir and mix evenly (the water-cement ratio is controlled between 0.7 ∽ 1: 1), and then use the prepared cement slurry to level off, and then level off the cracks. In view of the fact that the cast-in-place slab on the operation surface has been cured for less than two days, steel bars should be installed and the floor surface changes should be closely observed at any time. If there are cracks, dry shrinkage crack treatment method should be adopted, and the internal management of the project department should be strengthened. In the later construction, the concrete strength can't reach 1.2N/mm2, and the load can't be determined.

4. The post-cast strip is dismantled too early, which has hidden dangers of quality and safety.

4. 1 Remedial and preventive measures

After the demolition of post-cast strip, the formwork should be set up again. After the construction of all floors is completed and the concrete age on both sides of the post-cast strip reaches 60 days, the post-cast strip will be cleaned and poured with higher-grade expansive concrete.

5. Acceptance of individual types of steel bars is not in place when they enter the site. For example, HRB400 rebar with the batch number of 12 1202800 and the diameter of 12mm has never seen a clear quality certificate.

5. 1 Remedial measures

The rebar whose batch number of individual rebar nameplates is inconsistent with the retest report shall be re-sampled and sent to the test center for retest under the witness of the site supervisor.

6. The construction unit did not observe the settlement of the project.

6. 1 Remedial measures

The construction unit has arranged a qualified professional testing unit to enter the site, and observe the settlement of each building every half month, with a settlement observation report attached. On the basis of professional testing units, the project department also observed each floor of each building and attached observation records.

7. The project has not gone through the construction permit formalities.

Because there is no land use index for the south plot, it is impossible to go through the relevant construction application procedures, and the construction permit for the north plot is being processed at the window of the Construction Committee.

In view of these on-site problems, the project department has formulated relevant responsibility measures, strengthened the control of the project, and made technical disclosure to the parts prone to quality problems in construction again to ensure that each actual construction worker is familiar with the operation process.

Scheme 3: Project quality improvement scheme.

Project xx started in May of 20xx and was completed in September of 20xx. Xx project is gravity sloping shoulder wall, and the atlas numbers are 04J008-FJA3/57, FJA4/57 and FJA5/57 for construction. Composed of wall and floor, it mainly relies on the self-weight of xx project to maintain stability and play the role of retaining soil. In the process of the owner's inspection of the masonry quality of xx project, it was found that there were some quality problems on the inner side of the wall, such as some cross-sectional dimensions failed to meet the design requirements, some cement mortar was not full enough, some stone masonry did not meet the construction specifications, and there were holes and loose stones. After the inspection, our company attached great importance to this situation, and immediately sent company leaders and engineers and technicians to the site to inspect, analyze the causes of quality problems, and study the treatment measures. In order to do a good job in the rectification of xx project, we put forward the following rectification scheme opinions for the owner and supervisor to review:

1. Excavators and loaders cooperate with manpower to dismantle the wall in sections, and then temporarily fill it to the natural ground (except for the parts with qualified quality agreed by both parties). Then clean the muddy stones and slurry surface inside the xx project with water, so as to find out the quality problems existing in the whole xx project, and put forward on-site rectification opinions with the owner and supervisor in sections.

2. The following measures will be taken to rectify the xx project with potential quality hazards:

(1) For the wall section with large hole area, if most holes reach or exceed the center line of the retaining wall, the wall shall be demolished and rebuilt according to the requirements of construction specifications; If the hole is not deep, plug it with cement slurry and repair it with a hammer with a suitable stone;

(2) If it is found that the section size of the wall is not enough, the outsourcing method will be adopted: firstly, the existing natural floor will exceed the original section size by 300-500mm, and the construction joint will be built while pouring, and the interlayer will be set with masonry interlayer extending into the original xx project, with the length not less than 200mm. Bury the drain pipe according to the specification.

(3) The section size meets the requirements, only where the mortar is not full, it shall be filled with high-grade cement mortar, and the wall section with a small number of holes shall be filled with mortar by slurry plugging method, and then filled with stones until it meets the specification requirements.

(4) For the part of the wall in which the stone particle size exceeds one meter, dismantle the wall that does not meet the requirements, and re-build it after the stone is reduced to meet the requirements.

3. In order to ensure the smooth drainage after atmospheric precipitation permeates the soil in the backfill area behind the wall, first check whether the existing drainage pipeline meets the requirements. Secondly, it is suggested that the gravel with the thickness of 10- 15 cm should be set on the inner side of xx project as the filtration and permeability-guiding layer, which will be gradually put in place with the increase of backfilling behind the wall of xx project; And control the compactness of backfill soil within two to three meters behind the wall. Backfill soil shall be filled in layers with the above treatment measures and compacted manually.

4. In order to ensure the quality of rectification, our company set up a rectification leading group composed of the company's deputy general manager, the company's deputy chief engineer and the project leader. Responsible for on-site construction, and daily manage the construction quality, safety and progress of on-site materials and operators.

5. After the rectification of each xx project is completed, please invite the owner's project management personnel and supervision engineer to the site for acceptance.

6. After the rectification plan is determined, start work on time within three days. In order to complete the rectification task as soon as possible, more than 12 construction workers will be arranged for construction every day, and the whole rectification plan will be completed in about 30 days.

Engineering rectification scheme (II)

Beautify the living environment to further enhance the city's taste. In order to promote the establishment of a national garden city, the municipal government decided that all the buildings along the main and secondary roads in the city should be lit.

I. Time limit for completing lighting The construction units and building owners who have completed lighting facilities should complete the maintenance work before the month, and the units and building owners who have not completed lighting facilities must complete the construction of lighting facilities before the month.

Second, the form of lighting facilities, related units, buildings …

Beautify the living environment to further enhance the city's taste. In order to promote the establishment of a national garden city, the municipal government decided that all the buildings along the main and secondary roads in the city should be lit.

First, the time limit for completing lighting construction.

Units and building owners who have built lighting facilities should complete the maintenance work before the month, and units and building owners who have not built lighting facilities must complete the construction of lighting facilities before the month.

Second, the form of lighting facilities

All relevant units and building properties mainly adhere to the principle of doing good deeds, being beautiful and practical, and adjust measures to local conditions. According to the characteristics of the building and the surrounding environment, lamps such as detective lights, contour lights, scattered lights, waterfall lights, neon lights and laser lights can be selectively arranged. Lighting should also be installed for structures with "hats" and wrought iron fences facing the street.

Third, lighting time.

Buildings on both sides of the above roads will be turned on on time from a certain day of the month. The lighting time is: summer 19:30 to 22:30, winter 18:30 to 22:00.

Four, lighting facilities construction costs and system management

In the future, all units and building owners will bear the construction cost of lighting facilities themselves, and the lighting electricity fee will be borne by the municipal finance from 1 month, and the lighting facilities will be connected to the central control room of the municipal street lamp management office. The municipal urban management bureau is responsible for the construction of the central control room, and the funds are solved by the municipal finance. After the completion of the project construction before the end of July, the municipal street lamp management office is responsible for the unified management of lighting facilities.

V. Supervision, Inspection and Acceptance of Lighting Engineering

All relevant units and the construction industry mainly attach great importance to this work, make careful arrangements, complete the maintenance and construction tasks of lighting facilities on time, and ensure that the lights are lit as required. The supervision, inspection and acceptance of the lighting project shall be the responsibility of the Municipal Urban Management and Law Enforcement Bureau, and informed criticism shall be given to the units and building owners who fail to complete the lighting task as required.