by 1、 The site is provided with a prefabrication site.
1.
The site is selected according to the actual situation of the project.
Enclosed management is adopted to set the entrance and exit of the site.
Construction access roads are reserved in the planned area of the site, and various signs are hung at the entrance and exit as required.
2.
The layout of the prefabrication yard shall be in strict accordance with the requirements of the standard factory, the occupational health and safety and environmental management system and the HSE operation instructions.
All kinds of safety and environmental protection facilities shall be provided to meet the requirements of safe and civilized production.
The sewage discharge and garbage disposal shall be in strict accordance with the relevant regulations of the local government departments.
3.
The prefabrication site shall be cleaned, leveled, vibrated and compacted.
The 20cm thick cement stabilized macadam base shall be paved, leveled and vibrated.
The 15cm thick C20 commercial concrete shall be poured on the cement stabilized macadam base for the main access road in the plant area.
The 10cm thick C20 commercial concrete shall be poured in the reinforcement processing and installation areas, prefabrication and production areas, and the natural maintenance and placement area of the comprehensive pipe gallery.
The foundation trench with a depth of 60cm shall be excavated at the gantry crane track erection location, and the concrete shall be poured and the track laying trench shall be set.
The following three points should also be achieved: (1) The site needs to be cleaned and leveled, including the prefabrication site, the connection between the construction operation zone and the existing transportation road, and the passage in the prefabrication site.
(2) Stones, weeds, trees, structures, etc.
that affect the passage of construction machines and tools or construction operations in the prefabrication site shall be cleaned up, ditches and ridges shall be leveled, and low-lying sections with ponding shall be drained and filled, and replaced if necessary, to fully ensure the flatness and bearing and compressive capacity of the ground.
(3) The cleaning and leveling of the prefabrication site shall be followed to save or occupy less land, not hinder traffic, not damage buildings, facilities, historic sites, etc., and prevent environmental pollution and water and soil loss.
4.
In the prefabrication yard, the reinforcement processing and installation area, the steam curing area for prefabrication production of the comprehensive pipe gallery, the natural curing shed for the comprehensive pipe gallery, the storage area for the comprehensive pipe gallery and other functional areas are arranged.
The office area and living area shall be set according to the actual situation, and the guard room shall be set at the entrance and exit of the prefabrication yard.
2、 Production Process Flow Chart 1.
Mobilization of construction materials for reinforcement works, sampling for inspection, reinforcement processing, reinforcement binding and installation.
(1) Rebar mobilization inspection a.
The rebar is hot-rolled HPB300 rebar and hot-rolled HRB400 rebar.
The standard strength of the rebar meets the requirements of Article 4.2.2 of GB50010-2010, and the ribbed rebar meets the requirements of Steel for Reinforced Concrete: Part II: Hot Rolled Ribbed Rebar (GB1499.2-2007); Plain round steel bars shall comply with the provisions of Steel for Reinforced Concrete: Part I: Hot Rolled Ribbed Steel Bars (GB1499.1-2008).
Q235-B steel is used for steel plate, and E43 welding rod is used for welding HPB300 steel; E55 electrode is used for welding HRB400 steel.
B.
Before entering the site, the type, grade, specification and quantity of reinforcement shall be checked in strict accordance with the requirements to ensure that they are consistent with the material list, and whether the product certificate, factory inspection report, entry re inspection report and other factory quality certificates are complete, true and effective.
Test pieces shall be taken for mechanical property inspection, and their quality must comply with the provisions of relevant standards.
C.
Before entering the site and using the reinforcement, check the appearance quality of the reinforcement, whether it is straight and free of damage, whether the surface is free of slag inclusion, double skin, cracks, oil stains, granular or flaky old rust, and the color is consistent.
Check that the diameter of the reinforcement meets the requirements, so as not to affect the strength and anchorage performance of the reinforcement.
The inspection of steel plates, welding rods, etc.
before mobilization is the same as that of reinforcement.
(2) Storage of steel bars a.
The mobilized steel bars shall be stored in the steel bar storage area by category and tag according to the type, specification and level, and shall be accepted and warehoused by the materialman and storekeeper.
The steel bars shall be covered and padded to prevent rusting.
B.
Check whether the reinforcement has factory certificate, factory inspection report and mobilization re inspection report.
Check the appearance quality and batch representative diameter.
The quality indicators of the steel bars must be comprehensively checked.
The 60t steel bars that are inspected by batch for diameter and weight deviation and entered into the same construction site at the same time with the same factory, the same furnace number, the same specification, the same production process and the same time are regarded as an inspection batch.
The steel bars that are less than 60t are also regarded as an inspection batch for witness sampling.
The sampling of reinforcement shall be conducted in the presence of the supervising engineer.
Two tensile test pieces with a length of about 450mm and two cold bending test pieces with a length of about 350mm shall be taken from each of the two reinforcements and put into the test box.
Then the supervisor shall seal the box or send it to the supervision laboratory.
If one of the results of the retest report is unqualified, double samples shall be taken and retested.
The retest report shall be qualified and signed by the professional supervision engineer before the batch of reinforcement can be processed and used.
The storage of other materials shall be classified and kept away from moisture.
(3) Before reinforcement processing, the blanking length of each type of reinforcement shall be calculated and determined according to the design specification, length and quantity, combined with different processing technologies, to ensure accuracy.
During processing and fabrication, check whether there are errors and omissions in the blanking table.
Check each type of rebar according to the blanking table.
After these two checks, set out the actual samples according to the blanking table.
Only after the trial production is qualified can the rebar be manufactured in batches.
The processed rebar should be listed and stacked orderly.
The surface of reinforcement shall be clean, and the adhered oil, soil and rust must be cleaned before use.
The reinforcement shall be straightened mechanically.
The straightened reinforcement shall not have local bending, dead bending or small wave shape.
The reinforcement shall be cut according to the number, diameter, length and quantity of reinforcement, and the length shall be matched.
The long material shall be cut first and then the short material shall be cut.
The short end of reinforcement shall be reduced and shortened as far as possible to save steel and reduce loss.
When bending the reinforcement, the bending point shall be determined by setting out, and the bending angle shall be determined according to the rebound strength of each reinforcement.
Before formal bending, the steel bars bent in large batches can be bent in batches only after passing the test bending and confirming the relevant technical data.
After the reinforcement is bent, an arc is formed at the bend, and the size after bending is not greater than the blanking size.
The bending adjustment value shall be considered..
