Jerry-building is an act taken by all parties in engineering construction to lower the engineering quality standards, violate the engineering construction quality acceptance standards and evade the quality supervision and acceptance procedures. Strictly speaking, it is illegal.

1, mainly involving three related aspects:

Owner: In order to reduce the project cost, designers and constructors are required to adopt or use low-quality materials and components for design and construction.

Construction unit (including general contractor, subcontractor and team): the material quality is lower than the design and specification requirements, and the construction process is not carried out according to the construction technology standards and quality acceptance standards.

Supervision unit: failure to perform supervision duties, failure to strictly implement acceptance procedures, etc.

The general contractor is the organizer and direct controller of engineering construction, the core and key subject of engineering quality control, and should play a leading role in preventing construction from cutting corners.

Second, the direct cause and root cause of unqualified quality What are the common forms of cutting corners?

1, reinforcement works

1) too thin steel binding, jumping binding, missing binding, especially the missing binding of the steel bar at the bottom of the beam.

2) There are often 1 ~ 2 encryption hoops at the joint of frame column and beam, and some of them only have outer hoops without inner hoops.

3) No steel bars and additional steel bars are installed.

4) Put less or less protective pads, especially at the bottom of the beam.

Exposed reinforcement of column

Exposed reinforcement at the bottom of the slab

Exposed reinforcement at beam bottom

5) The original steel bar is cut unevenly, and the number of effective threads of straight thread connection is insufficient.

6) When using "slimming reinforcement", the stretching rate of coiled reinforcement exceeds the specification requirements (the cold drawing rate of round steel should not be greater than 4%, and the cold drawing rate of ribbed reinforcement should not be greater than 1%).

2, template engineering

1) The thickness, size and quality standard of formwork and wooden Fang can't meet the requirements, and the thickness of steel pipe fasteners is too thin and seriously corroded.

2) The formwork support is not provided with sweeping bars, the spacing between vertical and horizontal bars is too large, the non-slip safety fasteners are not fastened properly, and the vertical and horizontal bars are not provided at the upper part.

The non-slip safety buckle is not buckled properly; The length of the upper end of the vertical rod protruding from the top horizontal rod exceeds the specification requirements.

3) When the flat-fell seam of the formwork is too large, effective measures are not taken, but snakeskin bags are used for plugging.

4) Screw spacing is not implemented as planned.

5) template reinforcement is not in place, leading to template leakage and template expansion.

6) Before the column wall is closed, the loose concrete, sawdust and sundries at the bottom are not cleaned; Sawn wood ash and sundries at the bottom of the beam are not cleaned up.

7) Beam-column joints with different concrete grades don't need to be blocked with steel mesh or blocked loosely.

3, concrete engineering

1) The cement parameters in the mixture ratio of commercial concrete are low.

2) Don't wet the template before pouring concrete.

3) Adding water in the process of concrete pumping and pouring.

4) When the concrete is cast, it will leak as it is cast and vibrate at will.

5) There is no secondary plastering, lighting, water conservation or insufficient maintenance time on the ground.

6) The construction joints are not roughened, such as loose concrete and laitance at the construction joints of column walls.

7) There is no secondary watering for the hanging holes on the roof and bathroom, which is easy to cause leakage.

(1), the hole is chiseled.

(2) Rinse the surrounding plain cement slurry again.

(3) High-grade strength fine stone concrete is poured twice, the first concrete thickness is controlled at 1/3 ~ 1/2 thickness and compacted with steel bars, and the second concrete is poured away from the slab mouth for light treatment.

(4), again with waterproof material to deal with it (50mm on the side of the pipeline to the building elevation, and holes on the side of 150 ~ 200 mm), and do the closed water test.

8) When the concrete is cast, there is no steel worker or carpenter on duty, and no one handles the operation and critical formwork.

9) When pouring the post-cast strip, it shall not be cut, cleaned, pumped or maintained.

4, masonry engineering

1) The block size deviation is large, the curing age is insufficient, and the quality does not meet the requirements.

2) Block shall not be wetted in advance, and dry brick shall be pasted on the wall when laying.

3) The mortar is not full.

4) The anchorage length of masonry Rachel bar planting bar is insufficient and loose.

5) Rachel bars are not set on both sides of constructional column and construction hole according to specification requirements.

No tie rod

Rachel's bar is set up.

6) Concrete pouring at the top of constructional column is not dense.

5, plastering engineering

1) Before plastering, the wall junction made of different materials leaks the net.

2) Plastering has no corner protector, and the number of cakes is too small, so it can survive once when plastering, and there is no maintenance after plastering.

6, waterproof engineering

1) Non-standard products are used as waterproof materials, and indicators such as insufficient coil thickness are not up to standard.

2) During waterproof construction, the grass-roots treatment is not in place, unstable and unclean; Yin and Yang angles shall not be arc angles, and waterproof additional layers shall not be made.

Anti-base details

Concrete waterproof base is firm, clean, smooth, calendered and sand-free.

The angle of yin and yang at the base of coiled material waterproof surface should be smooth.

Circular arc diameter requirements: asphalt waterproofing membrane 200~300mm, polymer modified asphalt waterproofing membrane 100mm, and synthetic polymer waterproofing membrane 40mm.

3) The coil lap is not tight, and the end does not meet the requirements.

Press the coil into the groove of the wall, fix it with wooden nails, and seal it tightly with sealing material. The height of the groove is not less than 250mm from the finished surface of the roof, and the upper wall of the groove is waterproof.

7. Other materials

Semi-finished products and finished products can not meet the requirements of national standards, that is, the so-called "non-standard" products, such as the thickness of stainless steel pipes for railings, ceramic tiles and other decorative materials, and many subcontracts rely on poor quality rather than good quality to make profits.

Third, the prevention and control measures to cut corners

1, strict material acceptance system, to prevent shoddy, shoddy earn price difference.

2, completes the disclosure in advance, disclosure content should be operable, clear process standards and quality acceptance criteria. For parts with complicated working procedures and frequent quality defects, we must set an example.

3, in the process of regular review and inspection.

4, after the completion of the process to strict acceptance procedures.

5. There should be penalties and remedial measures for frequent quality problems. ZuoYeDui and subcontractors who refuse to mend their ways after repeated admonitions should be removed from the field.

I believe that after the above introduction, everyone has a certain understanding of it. Welcome to Zhong Da for more information.

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