1, division of building ground engineering, division engineering and sub-division engineering.
2, building ground engineering materials should be selected according to the design requirements and the provisions of the GB50209 specification, and should comply with the provisions of national standards; Materials entering the site should have Chinese quality certificate, specification, model and performance test report, and important materials should have re-inspection report.
3. The slabs of toilet, bathroom and building floor with anti-skid requirements should meet the design requirements.
4. The height difference between the toilet, bathroom and kitchen and the building ground surface layer and the connected surface layer with drainage (or other liquid) requirements should meet the design requirements.
5. The inspection method shall meet the following requirements:
(1) Use steel ruler, 2m guiding rule, wedge feeler, slope scale and spirit level to check the allowable deviation;
(2) check the empty drum by tapping;
(3) Check the base (each structural layer) and surface layer of the building ground with waterproof requirements, and sprinkle water or store water for not less than 24h；;
(4) Check the surface defects such as cracks, peeling, pits, sanding, etc. of various surface layers (including local or local surface layers that do not need to be laid), and adopt the method of perception.
(2) Laying at the basic level
1, allowable deviation of base surface and inspection method (mm)
2. Basic soil
3, lime soil cushion
4, sand cushion and gravel cushion
5. Gravel cushion and brick cushion
6, concrete cushion
7. Slag cushion
8, cement concrete cushion
9, leveling layer
10, isolation layer
1 1, packaging layer
(3) the overall surface layer laying
1, allowable deviation of integral surface course and inspection method (mm)
2, cement concrete surface
3, cement mortar surface
4, terrazzo surface
5, cement steel (iron) chip surface
6. Oil-proof surface
7, no ignition (explosion-proof) surface
(4) Paving the board surface
1, allowable deviation and inspection method of plate and block surface (mm)
2. Brick surface
3. Marble surface and granite surface
4, precast slab surface
5, stone surface
6, plastic surface
7, raised floor surface
8. Carpet surface
(5) Wood and bamboo pavement.
1, allowable deviation of wood and bamboo surface and inspection method (mm)
2, solid wood floor surface
3, solid wood composite floor surface
4, medium density (reinforced) composite floor surface
5, bamboo floor surface
(6) Pre-control project for construction supervision of building ground engineering
1, the main materials and semi-finished products used should have certificates, and new materials, new technologies and new processes should be retested according to the design requirements to obtain qualified grades. For plates with high material requirements, manufacturers should inspect and screen the products. For wood, attention should be paid to controlling moisture content and color. After the materials enter the site, conduct quality acceptance to ensure that the unqualified materials cannot be used in the project, and urge the construction unit to do a good job of storage.
2. Carry out quality acceptance on the paved ground. The elevation, slope, surface cleaning, sweeping and smoothness of the base shall be checked against the relative relationship between the drawings and the constructed parts, and the contractor shall make necessary treatment.
3. Technical disclosure shall be made to the construction management personnel and operators, and the supervision engineer shall review the construction scheme and technical disclosure sheet, and conduct model tests to guide the construction when necessary.
(seven) the main points of supervision and control of construction quality of building ground engineering
The supervision engineer shall supervise the contractor's strict operating procedures to eliminate common quality defects (uneven ground, hollowing, cracks, leakage, etc.). ) Divide here.
1, basic quality control point
(1) The soil quality of foundation soil shall be audited to determine the best dry density of soil; The construction should be controlled under the optimum water content, and the thickness of virtual paving should be controlled to ensure layered compaction. It is forbidden to backfill clods and frozen soil with particle size greater than 50 mm, and the supervision engineer should strengthen patrol spot check and layered hidden inspection.
(2) Lime should be digested and sieved in lime base. Before paving, lime should be mixed in strict proportion and paved at the best water content. The virtual paving thickness should be controlled at 150-250 mm and compacted by layers.
(3) Plain concrete base (cushion layer, leveling layer), mix proportion should be controlled before construction, test blocks should be retained during construction, and maintenance should be carried out after paving (at least 3 days).
2, the overall surface quality control points
(1) concrete or mortar surface course
Cement mortar surface should be no less than 325 Portland cement or ordinary Portland cement. It is forbidden to use cement soil. Different varieties and grades of cement should be used for expired cement or concrete. Sand should be medium sand or fine sand, with silt content not more than 3% and cement mortar consistency not more than 3.5cm.: ; The particle size of concrete stones should not be greater than 15mm and 2/3 of the surface thickness.
Supervise the contractor to clean the bottom of the pool and sprinkle water for wetting; Before the pavement layer, you should brush plain cement slurry and spread it with the brush to prevent hollowing.
Supervise and urge the contractor to carry out calendering in time according to the process requirements. It is generally required to survive three times. The second calendering should be carried out before the final setting. After the cement floor is calendered (generally after 12 hours), it should be maintained by water spraying, and the continuous maintenance time should be no less than 7 days and nights to prevent sand formation and wear resistance.
3, plate surface quality supervision points
(1) Variety, color and quality of plates (precast terrazzo, marble, granite glazed tile, etc. ) should comply with the design requirements and relevant national acceptance specifications. Check and accept the technical grade, luster and appearance of marble and granite plates. The quality of the floor should also meet the current national product standards.
(2) Supervise the contractor to organize manpower, according to the design requirements, try to spell according to the color, pattern and pattern texture of the plate before laying, and number it; Reject plates with cracks, corners, warpage, arching or surface defects. Different kinds of plates can't be mixed.
(3) In order to prevent empty drum, the base should be cleaned and fully wetted, and then laid after the surface is slightly dry; Hard mortar is used for paving, and the ratio of lime to sand is 1: 2 (volume ratio); The corresponding mortar strength is 2Mpa, and the mortar consistency is 25-35mm. Before laying, brush a layer of plain ash at the grass-roots level (it is forbidden to lay it at one time).
(4) In order to prevent uneven joints, especially where the doorway meets the corridor, the supervision engineer shall review and adjust the elevation when the blue prints.the design.
(8) Common quality problems in building ground engineering
1, common fault of lime-soil cushion
(1) The material does not meet the requirements;
The soil is not sieved, the particle size exceeds 15mm, the clay (or silty clay and silty soil) is not utilized, and the clay (or silty clay and silty soil) contains organic matter;
Lime is not fully digested, and its particle size exceeds 5 mm
(2) Improper mixing ratio and uneven mixing;
The proportion is not excessive, and the mixing is not sufficient;
Improper humidity (it is advisable to hold the ball in your hand and blossom on the ground).
(3) Poor compaction;
Excessive paving and false tamping (generally 150 mm- 100 mm, 250mm-200mm);
Non-layered dry density measurement;
The corner is not compacted;
Uneven thickness; Not enough.
2. Slag cushion
(1) Bad material
Slag contains organic impurities and unburned coal;
The particle size is too fine, and the particles of 5mm and below account for more than 40% of the total volume.
(2) the mixture ratio is not allowed, there is no bucket, or the mixture ratio is improper, the mixing is uneven, and the strength is too low.
(3) Beat pressure difference
Not boring (at least 5 days);
Too little or too much water;
Before paving, the base is not wet;
Poor compaction, false angle;
Uneven thickness (or improper control when slope is needed).
(4) Poor maintenance, early dehydration and loose surface.
3. Cement concrete cushion
(1) The gradation of sand and gravel is too poor, so there is no trial mixing and no test block will be made.
(2) Don't wet the base first, don't embed pipes or reserve grooves, and then scrape and plane.
(3) The large bay concrete cushion is not divided or divided too much (the longitudinal contraction joint spacing is not more than 6m, and the transverse contraction joint is not more than 12m).
(4) the surface is uneven, the thickness is uneven, and the maintenance is not good.
4, cement mortar surface
(1) Empty drum
Cushion (base) is not clean, holes are not well blocked, pipelines are not well protected, buried pipes are not well fixed, and acceptance is not serious.
The cushion layer (especially the slag and ceramsite concrete cushion layer) is not strong enough or loose, and if there are no measures to wipe the floor, it will be empty in nine cases out of ten;
The ground base is not wet enough (especially the balcony, kicking, and doorway ground are more easily overlooked);
Pipe root hole plugging is not firm and there are inclusions; The rear safety tube is damaged by planing;
Instead of brushing plain mortar, the grey surface of the bonded layer of plain mortar is sprayed with water, which is not effective and uneven.
The plain paste adhesive layer is not brushed with a brush, but brushed in advance. When the surface layer is plastered, the plain paste adhesive layer has dried to become an isolation layer.
The water-cement ratio of mortar is too large or there is water in the base, which affects the strength of mortar and the bonding between mortar and base;
The base layer is uneven, the surface layer is uneven in thickness, and it is easy to crack if it is too thin or too thick; The special cushion covers (buries) a pipeline, the elevation of the top of the pipeline is too high, the surface layer is too thin, and it cracks along the pipeline;
At the entrance, corner and pipe root, the surface layer is thin and leaks pressure;
High curing temperature in winter, long-term baking and early dehydration;
Poor maintenance, people loading things too early, the next process is done too early, and external vibration is empty.
(2) cracks
Cement is unqualified (expired, poor stability, low grade);
The sand is too fine and contains too much mud;
Large water-cement ratio, inaccurate ratio and uneven mixing;
Poor quality of cushion, false vibrating of concrete, lax connection, affecting cement floor,
Surface construction joints do not correspond to surface framing joints;
The grass-roots level is uneven, and the surface layer is uneven in thickness;
The ground fill and foundation soil are not solid and uniform, and the settlement deformation affects the ground;
Floor slab and ditch cover plate are installed without ash, and the slab is inclined;
The top elevation of pipes, embedded parts and trench cover plates is too high;
Surface calendering makes the cement surface dry, and uneven watering makes the surface shrink unevenly;
Large area ground without expansion joints;
Baking in winter, early dehydration;
The temperature changes greatly or it is windy, and the water evaporates too fast;
Poor maintenance;
The concrete pouring of floor joint is not dense, or even dry-squeezed;
After the floor is grouted, a large load is applied immediately, which makes the slab joint concrete lose the function of cloud sealing and force transmission. After the ground is plastered, the floor is easy to deform, which affects the ground.
In a large bay, the end seam of the upper plate of the beam or the opposite floor is located at the door, and the ground cracks (lack of steel wire mesh);
At the entrance of brick-concrete structure, the bricks are too high and the plastering is too thin.
(3) Super sand and super pit
Unqualified materials (low cement grade, expired; The sand is too fine and the silt content is large);
Improper ratio, inaccurate ratio and excessive water-cement ratio;
Improper calendering timing (too early or too late);
The cement surface is calendered and dried (1: 1 cement sand ash is not spread evenly as required), peeled and sanded;
Improper maintenance, premature dehydration or premature freezing in winter baking;
In the morning, people get on things and get on the bus to destroy the cement hard film;
Dust the bottom layer and unload the mortar.
(4) The ground immersion does not meet the requirements.
Civil engineering does not cooperate with launching, the elevation of embedded floor drain is not allowed, and it is not checked before civil engineering construction; Generally speaking, the toilet is required to be 20mm lower than the corridor, and the floor drain is 30-40 mm lower when the slope is 2%. The floor drain is 5mm lower than the surrounding ground, and the floor drain elevation should be 55-65mm lower than the corridor. If the waterproof layer extends into the floor drain, the waterproof thickness should be 5 mm and the cement surface thickness should be 20mm, that is, the floor drain elevation is 80-90 mm lower than the corridor.
Ground elevation control is not allowed;
There is no slope on the balcony floor, or the outside is high and the inside is low, or the drainage pipe is buried high and inclined, and the water is inexhaustible, or the drainage pipe is buried low, with small diameter and blockage.
(5) Surface damage and pollution
Low surface strength;
There are no protective measures, such as mixing ash on the ground and destroying the surface with a hard shovel;
The surface layer is not cleaned or damaged during cleaning;
Oil, mud and other pollution;
Improper process arrangement and engineering cooperation.
5, precast floor common fault
(1) Empty drum
Grassroots cleaning is not clean, wet is not good;
Brush slurry is uneven, or brush time is too long; Or sprinkle cement surface first and then sprinkle water instead;
1: 3 cement mortar is too thick to use hard cement mortar (it is advisable to hold it in your hand and bloom on the ground);
Do not brush the floating slurry on the back of the board, and soak it in water to dry;
Improper hammering, uncompacted, or eccentric hammering, too thin or uneven grouting under the plate;
When this piece is paved, the mat will be placed on another piece to shake the paved plate loose;
No maintenance, people in the morning, loading (sprinkler maintenance should be carried out 24 hours);
Poor joint filling (the surface layer and cracks are not cleaned first, mud is poured several times, and cement is strictly prohibited);
The mosaic is not well shot, the pulp is not well returned, and the pieces are loose and fall off;
(2) The joint is not straight and the joint width is uneven.
Plate shape (thickness, width, channeling angle, warping, etc. ) is not standardized, and the materials are not selected and pre-discharged;
The elastic lines of the elevation are different, and there is no crossing at the door, resulting in the wrong platform;
Don't pull the wire;
Mosaic is not stitched, and the hammer is uneven. The curing time is short, which is too early.
(3) Damage and scratches
The quality of finished products is poor;
Improper handling, storage and safekeeping;
Not careful selection of materials;
The finished products are poorly protected, and there is no cover protection when they are mixed with ash, pushed by carts, operated, stacked and hit by hard objects, and mud pollution is not cleaned up in time.
(4) Do not select a color block.
(5) High-grade decorative floors don't play cross lines to find squares, rooms, rooms and corridors have no overall design considerations, joints are not harmonious, mouth fragments are paved, and boundary positions are wrong;
6, skirting board common fault
(1) Empty drum
Grassroots cleaning is not clean; Poor wetting of the base; Lack of high foundation at the grassroots level;
Conversely, cement stubble is pressed with lime stubble;
A plaster is too thick;
Frost hangs on the wall in winter to form an isolation layer;
(2) The upper opening is cracked
The cutting method is adopted in construction, the cutting time is improper, and the flow mouth is staggered;
No compaction and calendering after cutting;
The surface layer is pressed too late, resulting in a gap between the surface layer and the base layer;
Mortar is too thin and soft, or mortar is too thick, and cracks at one time.
(3) The wall surface is too thick, uneven in thickness, the flowing mouth and the angle of yin and yang are not straight, and the surface calendering is not good.
(4) The top of the baseboard is not straight, indoor and outdoor do not intersect, the facade is not vertical, and the intersection angle is not vertical.
(5) Precast skirting blocks are uneven, and splayed joints are not made at the external corners.
(6) After the project is completed, the surface pollution will not be cleaned up.
(7) If the base is not clean, brush cement slurry and oil and peel it off.
7, step common fault
(1) formwork support and (hoisting) reservation are improper, and the step height difference after decoration exceeds the allowable deviation of the specification.
(2) Precast stairs are not filled in time, not cleaned, not watered and wet, and filled falsely, which leads to cracks in plastering at joints.
(3) Poor finished product protection and lack of edges and corners.
(4) Stairs, slab bottoms and steps are poorly cleaned and wetted. There is no plain gray glue layer, and the plaster is cracked.
(5) Step plastering does not play the slope line, and the height and width are inconsistent.
(6) The tread anti-skid strips are too high and flat, with different lengths, and no wear-resistant materials are used.
(7) The end of the running board of the prefabricated grinding disc is not polished, the ash is not solid, and there are holes.
(8) The baseboard is not smoothly handed over to the ground and rest platform.
I believe that after the above introduction, everyone has a certain understanding of the Detailed Rules for the Implementation of Construction Quality Control Supervision of Building Ground Engineering. Welcome to Zhong Da for more information.
For more information about project/service/procurement bidding, and to improve the winning rate, please click on the bottom of official website Customer Service for free consultation:/#/? source=bdzd