Figure 10 Prefabricated formwork removal Figure 11 Prefabricated formwork maintenance 4.2.3 Positioning and setting out Before wall masonry, masonry positioning and setting out shall be carried out, including the specific plane position of the structural column.
The inner side of the block at the wire pipe position shall be grooved and buried.
5.4 The construction and masonry of the formwork shell above the masonry belt is the same as that of the part below the belt.
6 Small boiler and pressure gauge Fig.
Close the outer formwork shell, add the mixed C25 fine aggregate concrete, and start the formwork shell machine to automatically vibrate to make the concrete compact.
02 Scope of application 2.1 The structural column is free of formwork.
The outer formwork shall be removed first, and then the main control rod of the inner formwork shall be rotated by hand to make the inner wall steel formwork shrink, thus effectively separating from the prefabricated concrete formwork shell.
Remove each finished formwork shell in sequence and spray water for curing, and put it into use on site after about 7 days of curing.
to the bottom of the masonry waist beam), stop for one day until the masonry mortar reaches a certain strength.
The project of Nanjing Regional Company is actively promoting the use of the group company’s patented technology – prefabricated cavity formwork shell for the construction of structural column without formwork.
2.2 The distribution box, multimedia box and other boxes and conduits in the slotless masonry shall be buried.
In order to improve the shell forming progress and work efficiency, the concrete shell is cured by steam for 1 hour, and the steam is prepared by self-made small boiler.
the physical perspective photo of the structural column outer shell forming machine Figure 2JLT/205 close-up photo of the shell forming machine c.
5.5 Prefabricated cavity formwork shell reduces the section size of cast-in-place constructional column.
Research and develop the outer mold shell forming machine of the structural column, and professionally manufacture the cavity mold shell of the structural column.
The U-shaped hollow formwork forming machine for structural column is developed.
After the masonry mortar reaches a certain strength, the construction column fine stone concrete core pouring shall be carried out the next day.
Figure 14 Bottom of structural column formwork Figure 15 Masonry to the lower opening of the waist beam 4.2.5 Concrete core filling is poured together with the masonry belt the next day.
01 In the project example, the conventional practice of secondary structural structural column is to use formwork to reinforce and then pour concrete.
The strong and weak current box shall be prefabricated with small concrete components with the same modulus as the masonry, and the masonry shall be constructed simultaneously.
7 Steam inlet branch pipe Fig.
4.2 Key points of formwork free operation 4.2.1 Material preparation Prepare various raw materials for prefabricated formwork shell in advance, including rice gravel, 32.5 composite cement, galvanized steel wire mesh, release agent, etc., and entrust the testing center to do a good job of C25 fine aggregate concrete mix proportion test.
Figure 1JLT/205 close-up photo of the shell forming machine b.
8 Steam pipe layout Photo g.
Before prefabricating the shell, mix the cement, yellow sand and rice stone evenly, and add some yellow sand into the rice stone.
When the wall thickness is less than 120mm, it is not recommended to prefabricate the above structural column cavity mold shell.
3.2 No slotting of masonry Before masonry construction, the wire box and conduit shall be installed in place in advance.
03 Process principle 3.1 The structural column is free from formwork support, which changes the traditional formwork support mode.
5 Self-vibration site of shell forming machine f.
4.2.2 Mold shell forming a.
13 Setting out of top pouring slab bottom 4.2.4 The formwork shell masonry and aerated block wall masonry shall be carried out at the same time.
Before the fine aggregate concrete is poured into the formwork, the outer formwork shall be separated, and a layer of wire mesh shall be fully paved on the inner formwork; The partition baffle between the mold shells is made of square tubes, which can move and adjust the height required for forming the mold shell.
D.
When the structural column in the aerated block filled wall or brick wall is more than 120mm thick.
5.7 For the general residential building project, the concrete pouring in the structural column formwork shell is carried out in two times, namely the part below and above the belt.
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The prefabricated small component is used as the cavity formwork as the external formwork of the structural column, and the micro-expansion fine aggregate concrete is filled inside, which improves the work efficiency and further ensures the construction quality.
The wire pipe shall be jointed with two thin blocks.
Figure 16 Site photo of core sealing concrete pouring 05 Precautions for formwork free construction 5.1 The wall thickness of the cavity formwork shell of the prefabricated structural column is 20mm, and the fine aggregate concrete is used for formwork construction, and the proportion can be based on C25 fine aggregate concrete.
Before pouring, simple supports can also be properly added on the outer wall of the formwork shell to ensure that the formwork shell does not shift.
The core filling concrete inside the structural column cavity formwork shell is micro-expansion fine aggregate concrete Φ 30 The vibrating rod vibrates on the main reinforcement of the structural column, assisted by external tapping with a rubber hammer and blanking with a round steel tamping rod to make the pouring dense.
5.2 The internal and external steel formwork shall be cleaned in time and evenly coated with a thin layer of release agent every time each shell forming machine is prefabricated.
Figure 9 Photo of removal of external formwork h.
04 Formwork free process flow and key points of operation 4.1 Formwork free process material preparation for constructional column → formwork shell forming → positioning and setting out → masonry at the same time with the wall → fine stone concrete core filling → acceptance.
E.
12 Auxiliary setting out of infrared marker Fig.
The masonry at the wire box shall be cut in advance to reserve grooves.
5.3 Before wall masonry, it is necessary to conduct masonry pre-layout, adjust the height of the bottom structural column formwork shell, and adjust the height during prefabrication, so that the top formwork shell and the beam bottom are tightly combined.
Fig.
Fig.
5.6 Note: When the hollow formwork shell of constructional column is built on site, it is not allowed to cast concrete while building, otherwise the prefabricated formwork shell is easy to deviate.
When removing the formed form shell, it is necessary to remove it from the outside to the inside along the end of the steel form on the inner wall in order to avoid damaging the formed form shell.
After each 4~5 skin height (i.e.
The formwork shell shall be removed after 1 hour of steam curing.
Fig.
When the masonry is to the top, the upper opening of the formwork shell side can be opened or the U-shaped formwork shell opening can be built outward, and the concrete core pouring can be carried out.
To ensure the cast-in-place section size of constructional column, when precast concrete formwork shell, it can be 4 cm longer than the original constructional column in the length direction (along the wall).
For the laying of the central line pipe in the masonry infilled wall, we have broken through the conventional method of post-grooving and embedding the line pipe in the masonry, adopted the slotless construction process, and pre-buried the line pipe, with remarkable results.
The appearance quality of masonry is improved.
