What should be paid attention to in the construction of rural self-built houses

Several aspects that should be paid attention to in the construction of rural self-built houses;

(A) the preparatory work before construction

1, select the construction team

Before the project construction, the local construction team should be inspected, and a professional construction team with skills, construction machinery, construction experience and good comprehensive quality should be selected, preferably a qualified construction company.

2. Select design drawings and special general atlas (2006: Atlas of New Socialist Rural Housing in Anhui Province). The construction drawing is an important basis for the construction project, which directly determines whether the structural safety and use function of the project are reasonable. The supervision, acceptance and dispute handling in the construction process should be based on the drawings. Therefore, before construction, design drawings or select special construction atlas. If atlas is selected, the foundation should be inspected by professionals to ensure structural safety.

3. Location selection

Before building a house, we should investigate the surrounding geological environment. We should try to avoid building houses in ditches, ponds and places with cesspits and graves. In order to prevent the uneven settlement of the foundation, the house will crack or even collapse.

Step 4 sign a contract

After selecting the construction team, both parties should sign a formal contract to stipulate related matters (especially the project site selection, construction period, material and quality requirements, project quality, safety responsibility, warranty period, dispute settlement, project cost settlement, etc. ) in the contract.

(2) Important control points in the construction process

1, basis

(1) The foundation must be dug to the old soil layer, and the soil quality should be uniform, and the depth into the old soil layer should not be less than 20cm.

(2) The buried depth of foundation (from the lowest point of outdoor terrace after completion) shall not be less than the thickness of local frozen soil layer and not less than 50cm. If necessary, it should be designed. Backfill soil of foundation trench (pit) shall be compacted by layers.

(3) After the foundation is controlled to the bearing stratum, check whether there are holes and weak strata under the foundation with steel bars (coarse), and if there are any, remove them and dig them to the old soil.

(4) After the foundation bearing layer meets the requirements, the foundation construction shall be carried out immediately to avoid rain soaking and exposure. If there is any soaking, the soaked and softened foundation soil shall be removed before foundation construction; After the foundation construction is completed, it should be backfilled immediately to avoid being soaked by water and disturbing the foundation.

2. Slate foundation

(1) Rubble foundation masonry: Rubble foundation is built in layers with mortar (also between the first layer of rubble and soil), generally facing downward and staggered up and down. If the foundation is stepped, it should be laid from the lowest place;

(2) There should be gaps between rubble and compacted with masonry mortar. Dry paving a layer of rubble, then paving a layer of mortar, and then flushing the joints with water shall not be adopted to avoid cement being washed away by water.

(3) rubble masonry, should use high quality stone, can't use wind fossils.

3, brick masonry engineering

(1) The strength of the selected brick must meet the requirements, and it can only be used after being sent to the inspection department for inspection.

(2) The load-bearing wall shall be a 240mm solid brick wall (one brick and one wall), and bucket wall shall not be used as the load-bearing wall.

(3) In order to ensure the quality of masonry, it is forbidden to dry bricks on the wall, and a unified masonry method should be adopted. The fullness of horizontal mortar joint of brick masonry should not be less than 80% (i.e. the contact surface between brick and mortar); Masonry vertical joint mortar must be full, and the thickness of mortar joint should be controlled at 8-65438 02 mm. ..

(4) At the corner or intersection of brick masonry, masonry shall be constructed at the same time. If construction (masonry) cannot be carried out at the same time, an oblique fork (step fork) shall be left. It is forbidden to divide the punishment into two separate structures (except the constructional column here), so that there is no reliable connection between the vertical and horizontal walls, and even the walls may crack or even collapse. (5) At the corner or intersection of the wall with or without constructional column, the wall (not less than 2 Ф 6 reinforcement) shall be provided with Rachel bars every 500mm along the wall height, and the length of Rachel bars shall not be less than1m..

(6) It is forbidden to open horizontal grooves on the bearing brick masonry after masonry, or make holes in the wall at will.

(7) Masonry mortar shall be constructed in accordance with regulations, mechanically stirred, and water shall not be added at will when used. Must be used up within a certain period of time (before the initial setting of mortar loses its fluidity), and shall not exceed 2 hours. It is forbidden to use slag ash instead of lime paste and stone powder instead of sand.

(8) The lintel thickness of doors and windows must meet the requirements. The laying length of lintels on both sides of the wall should not be less than 250 mm, and the bottom of lintels should be grouted. If reinforced brick lintels are used, the diameter of the bottom reinforcement should be Ф 6-Ф 8 mm, and both ends should extend into the wall not less than 240 mm The reinforcement at both ends must be hooked, and the reinforcement should be not less than 3, and the strength grade of cement mortar should not be less than M5.

(9) For monolithic walls with two ends not connected with other masonry (such as constructional columns at both ends, but the constructional columns are not poured), the height of masonry should not exceed one step of scaffolding; If it must be exceeded, temporary stability measures should be taken to prevent the masonry from collapsing under the action of external force (such as strong wind).

(10) The width of the temporary hole used for construction traffic should not be greater than 900 mm, and the height should not be greater than1.8 m. A lintel should be set here. When filling the hole, build by laying bricks or stones on both sides.

(1 1) The foot-hand-eye blockage of the external wall should be dense, so as not to cause water seepage of the external wall.

4, concrete engineering

(1) Cement: expired (more than 3 months) and caked cement cannot be used. When buying cement, you should ask the seller for a cement certificate.

(2) Concrete shall be constructed in accordance with regulations. Mechanical stirring is adopted, and no water can be added during use. The concrete strength grade of main stressed members shall not be lower than C20 (beams, plates, columns, etc. ).

(3) The aggregates (stones and sand) for mixing concrete can't have mud balls and mud powder by visual inspection, the gradation should be reasonable (particle size), and the water quality must be clean and pollution-free.

(4) When pouring concrete, mechanical vibration should be adopted to ensure the compactness of concrete, and it is best to finish pouring at one time. When the construction joint is to be preserved,

It shall be located at 1/3 of slab or secondary beam and staircase. Cantilever beams and floors (such as bracket beams, awnings, balconies, etc.). ) In addition to the ring beam handover, no construction joints can be left anywhere, and they must be poured at one time; Vertical joints should be left for construction joints, and templates should be installed at the joints to prevent concrete from flowing freely.

(5) Concrete curing: At normal temperature, concrete should be covered, watered and kept moist. The curing time of self-mixed concrete is not less than 7 days, and that of commercial concrete is not less than 14 days.

(6) Pipes passing through the floor or reserved holes shall be retained in advance, and the retention position shall be accurate. Cast-in-place slab shall not be opened or slotted at will.

(7) It shall not be piled up 2-3 days after concrete pouring. After that, the temporary stacking load shall not be too large or vibrated, and the materials shall not be piled up centrally, so as not to damage the concrete structure.

(8) Balcony, kitchen, bathroom and roof should adopt cast-in-place concrete structure.

5, support system and template

(1) The strength, rigidity and stability of formwork support system should meet the requirements, especially the bottom support should be supported on hard objects, not directly on soft soil, the vertical support should be perpendicular to the ground as far as possible, and the vertical supports should be connected with each other to prevent the whole collapse caused by instability.

(2) Formwork flat-fell seam should be tight, so as to avoid cement slurry loss and holes and pits in concrete. And reduce the bearing capacity.

(3) The load-bearing structure (bottom formwork of beam and slab) cannot be dismantled at will, and the formwork can only be dismantled when the concrete reaches a certain strength (design strength is 70-80%, cantilever component strength is 100%) (generally 2 1 day in summer and the average daily temperature in winter reaches 600 degrees) to prevent the concrete structure from being damaged.

(4) When supporting the formwork, the elevation and axis of the formwork shall be re-measured (meeting the height and width of the bay).

6, steel engineering

(1) should be produced by a regular manufacturer (manufacturer) with factory certificate. Before use, it is best to send the reinforcement to a testing institution for testing. There should be no cracks and scars on the visual inspection surface. The longitudinal threads of threaded steel bars shall be uniform, and the cross section of circular steel bars shall be circular. Steel surface should be blue-black. If it breaks during processing, its quality may be unqualified, and it should be sent to a testing institution for testing.

(2) Cantilever structures, such as awnings and balconies. (that is, the position of the upper steel bar should be strictly controlled when selecting the slab and beam of the external wall, and the position of the steel bar should not be misplaced).

(3) The tail beam length of the cantilever beam in the wall should meet the requirements of overturning resistance and should be checked by professionals.

(4) When the balustrade of balcony and corridor is provided with single-layer steel bars, the vertical steel bars should be located inside, and the wrong position of steel bars should be avoided during construction to prevent the balustrade from overturning.

(5) The ring beam of brick-concrete structure must continuously penetrate the wall, and the constructional column should be integrated with the ring beam to enhance the seismic performance of the house.

(6) The hook of reinforcement should be 135 degrees, the hook should be straight, the length should not be less than 10 times of the stirrup diameter, the rebar joints should be staggered, and the rebar position of beam and slab should meet the requirements.

7, precast floor installation

(1) The prefabricated floor must use the products of qualified prefabricated factory, and the number of steel bars in the prefabricated floor (floor steel bars must be given).

The specification of the reinforced bar (5 mm in diameter) and the concrete strength (not less than C30) meet the specification requirements. At the same time, the appearance of precast floor slab should be checked, there should be no cracks and honeycomb holes (loose concrete), and the position of reinforcement must be correct. The manufacturer shall also provide the factory certificate of precast floor slab and the test report of floor slab bearing capacity.

(2) The precast floor slab cannot be slotted or slotted at will.

(3) The laying length of precast floor slab on concrete members (such as ring beams) shall not be less than 80mm. On the wall (brick wall) not less than100 mm; When installed in place, there should be a gap of 20-40mm between the two layers; When installed in place, the lower openings at both ends of the plate should be grouted, and the floor holes at both ends of the wall should be blocked with concrete;

(4) Treatment of the gaps between the installed floors: firstly, clean up the sundries in the gaps between the floors and cast them in two layers with fine stone concrete. Large gaps between floors should be filled with cast-in-place concrete, which should be cured for at least 48 hours at room temperature, and cannot be filled with bricks.

8, water and electricity, doors and windows, roofing, decoration and other content has a big relationship with time, so I won't say it here.

9. General Basic Provisions (Safety in Use)

(1) The height of balcony baffle shall not be less than 1.05m, and the height of parapet or railing on the owner's roof (the clear distance between vertical poles shall not be greater than 0.1m, which makes it difficult to climb) shall not be less than 1.05m, otherwise, the height of outer windowsill and stair handrail shall not be less than 0.9m.

(2) The clear height of the upper and lower aisles of the landing should not be less than 2m, the clear height of the flight should not be less than 2.2m, and the step width of the stairs in the suite should not be less than 0.22m and the height should not be greater than 0.2m.. ..

(3) The pace of each flight should not exceed 18 and should not be less than 3.

(4) The kitchen and bathroom should be 30mm lower than the floors of other rooms, and the balcony, outdoor and indoor floors should have a certain height difference.

(5) The load-bearing wall after construction cannot be dismantled, drilled or slotted at will.

10, acceptance and use

(1) Appearance inspection: When the project is completed and put into use, check the quality of the house, whether there are obvious cracks in the walls and plates, and whether there are leaks in the external walls, windows, kitchens, bathrooms and roofs. And the water and electricity should be tested.

(2) Check whether the contents agreed in the contract are all completed and whether the project quality meets the agreed requirements.