Construction Method and Main Technical Measures of Cement Pipe

First, the construction preparation work

measurement lofting and table cleaning work should be carried out according to the design slope and excavation height, the boundary line, topsoil, turf, roots and other unqualified fillers should be transported to the dump site unified stacking.

1, cement concrete pavement base construction

Before the construction of cement concrete pavement base, first compacted the original subgrade (or natural settlement for 2 to 3 months), then paved with water pressure sand 20cm for laying, and then compacted with a road roller.

1) Measuring the release line, according to the design position of the drawing, measuring the edge of the concrete board of the motor vehicle road and measuring the elevation, supporting the formwork.

2) C15 commercial concrete base preparation: according to the concrete plate division of C15 commercial concrete base elevation, flatness for re-testing, local ultra-high and uneven use of milling machine milling the surface of the base should be cleaned, too dry should be sprinkled with water to wet.

3) Template installation: The template is made of steel mold, the template installation requires firm and stable. Super deep with cement mortar in the lower part of the template filling. In addition, but also on the top of the template elevation, verticality, flatness, straightness of key control.

4) Concrete mixing and transportation: the use of commercial concrete, raw materials using electronic scales to control the weighing of the feeding system supply, in order to ensure the mixing ratio, and to ensure sufficient mixing time. At the same time control the water cement ratio, transport using concrete pump truck timely and quickly transported to the paving site.

5) Paving: After the concrete is transported to the mold warehouse, it is manually paved and formed.

6) Vibration: According to the order of "first four corners and then the middle", the plug-in vibrator, plate vibrator, and vibrating beam are used successively to ensure the compactness of the concrete.

7) When the concrete mixture is leveled, the concrete mixture with finer crushed (gravel) stone should be used to fill the plate surface, and pure mortar is strictly prohibited from filling and leveling. After leveling with the vibration beam, it can be further leveled with an iron roller. When there is a road arch, the road arch plate should be leveled. When leveling, the top surface of the formwork must be kept clean, and the plate surface at the joint must be flat.

8) Fine leveling and smoothing: After the concrete is fully vibrated, use a steel drum to flatten the surface to lift the slurry, and scrape the steel scraping ruler along the mold.

9) Seam cutting: The electric seam cutting machine is used, and the special person operates it. According to experience, the seam is generally cut within 12-15 hours after the concrete is poured.

10) Longitudinal steel bars in the concrete base plate are laid on both sides of the edge, transverse steel bars and corner steel bars are laid on the expansion joint and transverse edge, and the edge steel bars are disconnected at the joint. At the same time, the whole line is provided with steel welded mesh.

11) The longitudinal joints of the concrete plate are made of flat joints with pull rods, and the transverse shrinkage joints are made of false seams with force transmission rods. The edge reinforcement should be set on the free edge of the slab, and the corner reinforcement should be set on the free edge of the slab and the upper part of the corner at the expansion joint; when the concrete slab is divided into staggered joints, the edge crack reinforcement corresponding to the joint; The concrete slab around the rainwater outlet should be reinforced. For specific reinforcement measures, see the relevant design drawings.

12) The placement of the D6 welded steel mesh of the reinforced concrete slab should comply with the specifications. When placing the corner reinforcement, a layer of concrete mixture should be laid on the corner where the reinforcement is placed first. The height of the paving should be pre-added with a certain degree of settlement than the design position of the reinforcement. When the corner reinforcement is in place, the concrete mixture is about to be pressed. When placing the edge steel bars, a concrete mixture should be laid along the edge first, pat it down to the height of the steel bars, and then place the edge steel bars, and press it with the concrete mixture at both ends.

13) The construction of expansion joints, shrinkage joints and longitudinal joints shall comply with the specifications. The position of the construction joint should be consistent with the design position of the expansion joint or shrinkage joint. The construction joint should be perpendicular to the center line of the road surface, and the force transmission rod must be perpendicular to the joint wall. After the maintenance period of the concrete slab expires, the seam groove should be caulked in time. The caulking material is polyurethane caulking glue. Before caulking, the seam must be kept clean to prevent sand and gravel from falling into the seam.

14) health: the use of geotextile maintenance, health period of not less than 7 days, maintenance period prohibit any vehicles and equipment passage, and extend to 28 days before allowing vehicles to pass.

2, rain sewage pipeline project

rain sewage pipeline construction according to the site of the original rain sewage reserved mouth according to the requirements of Party A to extend,

1) rain sewage pipeline construction process

2) rain water drainage pipe is proposed to set up two rows, laid in the motor vehicle road, sewage pipe is proposed to set up two rows, the pipeline is located under the sidewalk. Since the rain pipe and sewage pipe construction method is basically the same, the construction organization design will uniformly introduce the rain water, sewage pipe construction method.

II. General requirements

1) Subgrade filling area, the construction of pipelines and inspection wells, and the subgrade filling cooperate with each other, when the subgrade filling is higher than the top of the sewage pipe 0.5m, first open the trench, buried sewage pipelines and inspection wells, and then continue the construction of the roadbed. When the roadbed is filled to the bottom elevation of the graded gravel layer, the construction of rainwater pipelines and inspection wells. Mechanical excavation of pipe trenches, slope 1:0.25.

2) Subgrade excavation area, after the trench is excavated, the pipeline trenches are excavated, and the construction of sewage, rainwater pipelines and inspection wells is carried out. Mechanical excavation of pipe trenches, slope 1:0.25, manual lifting of pipes in place.

3) After the pipeline trench is excavated, the bearing capacity of the trench foundation must be measured. The heavy-duty compaction method is used for measurement. The bearing capacity of the foundation can only be laid after meeting the design requirements. If the bearing capacity of the foundation does not meet the design requirements, it must be backfilled with crushed stone cushion. After treatment, the bearing capacity of the foundation is determined.

4) Measure the release line, rain and sewage pipelines, generally set the center pile every 20m, drainage pipeline release line, generally set the center pile every 10m. Central piles should be set up at the pipeline inspection well and the change pipe diameter, and protective piles or control piles should be set if necessary. After the drainage pipeline is leveled, the pipeline longitudinal section diagram should be drawn. The measurement work of the drainage pipe line should have a regular measurement record book, which should be carefully recorded in detail.

Third, the foundation of the pipeline

1. Pipeline foundation refers to a manually treated or specially constructed structure between the pipe or support structure and the foundation. Its function is to distribute the more concentrated load of the pipeline evenly, so as to reduce the pressure on the unit area of the foundation, or due to the needs of the special properties of the soil, a technical measure taken to ensure the safe and stable operation of the pipeline.

A complete pipeline foundation should be composed of two parts, namely the pipe base and the foundation.

2. Precautions for Pipeline Foundation Construction

(1) Before foundation construction, the elevation of the slope must be reviewed. Generally, the same pile is drilled every 4m or so at the bottom of the trench, and the sample pile is used to control the excavation surface, the cushion surface and the foundation surface.

(2) The bottom layer of the pipeline is backfilled with gravel cushions in layers, and the thickness of each layer is 200~ 300mm. Vibration compaction is used for flat-plate impact compaction.

(3) Backfill on both sides of the pipeline with gravel sand and gravel debris with a maximum particle size of less than 40mm, and the compaction degree must be greater than or equal to 90%.

4. Quality Standard

(1) Pipeline cushions and foundations shall not be laid on silt or loose fill.

(2) Pipeline foundations should be flat on the surface and straight between the two wells.

Fifth, pipeline quality inspection

Concrete pipes should be inspected for appearance when entering the site. The wall thickness of the pipes should be uniform, and there should be no cracks, holes, collapse and serious corrosion defects. The technical documents of the product should be complete, and should comply with the current technical standards promulgated by the state.

Sixth, pipeline foundation pouring

1) The pipeline foundation of this project adopts C15 concrete.

2) Before pouring the pipeline foundation, the bearing capacity of the crushed stone cushion at the pipeline foundation should be determined by the penetration meter whether it meets the requirements, and the next process can be carried out after meeting the requirements.

3) After measuring the bearing capacity of the crushed stone cushion meets the requirements, a formwork will be supported on the cushion according to the design requirements, and the concrete pillow foundation should be poured. The concrete adopts C15 concrete, and the concrete can only be carried out after reaching the design strength. Pipe distribution work.

4) After the pillow base concrete reaches the design strength, the pipeline is hoisted to the pillow base, and its position is fixed with red bricks to ensure that the center line of the two pipelines is consistent, and the axis of the pipeline is on the same straight line.

Source: Hubei AD Building Materials Co., Ltd., welcome to share! Hotline: 17399989993