Prefabricated House Beam Construction

The special plan for the construction of prefabricated house beams covers project overview, construction deployment, and key construction steps, as detailed below:

I. Project Overview and Compilation Basis
The project adopts a prefabricated concrete frame structure system, with prefabricated beams serving as horizontal load-bearing members that bear vertical loads and horizontal forces. It is necessary to clarify parameters such as the distribution floors, quantity, total length, and total weight of the prefabricated beams, and describe the cross-sectional form (rectangular, L-shaped, etc.), dimensions (e.g., 250mm×500mm), span (6m, 9m, etc.), concrete strength grade (C30~C40), and steel reinforcement configuration (longitudinal load-bearing steel bars using HRB400E-grade deformed steel bars, and stirrups using HRB400 or HPB300-grade steel bars). The compilation basis must strictly adhere to national standards such as the 'Code for Acceptance of Constructional Quality of Concrete Structures' (GB 50204-2015) and the 'Technical Standard for Prefabricated Concrete Buildings' (GB/T 51231-2016), as well as design document requirements.

II. Construction Deployment

1. Objective Setting: The quality objective is to ensure installation accuracy complies with specifications, with a 100% pass rate on the first inspection. The safety objective is to prevent major accidents and control the minor injury frequency within the specified ‰. The progress objective is to complete installation procedures according to the overall plan. The civilized construction objective is to clean up the site after work and reduce noise pollution.
2. Management Team: Establish a dedicated team and clarify the job responsibilities of the project manager, technical leader, quality inspector, etc.
3. Construction Principles: Adhere to the principle of 'factory production and on-site assembly installation'.
4. Process Planning: Include construction preparation (technical, on-site, material, and equipment preparation), on-site inspection and acceptance of prefabricated beams (appearance, dimensions, reserved and embedded parts inspection), and storage management.

III. Key Construction Steps

1. Construction Preparation

   • Site Layout: Set up a steel bar processing yard, beam prefabrication area, finished product storage area, etc., and reasonably plan the number of prefabrication pedestals and beam storage pedestals.
   • Pedestal Construction: The beam fabrication pedestal consists of a foundation (concrete strip or reinforced concrete spread foundation) and a pedestal surface (high-strength reinforced concrete). The beam storage pedestal must meet load-bearing requirements.
   • Materials and Equipment: Prepare materials such as steel bars, cement, and sand and gravel, and submit them for inspection. Overhaul and calibrate equipment such as mixers, gantry cranes, and tensioning equipment.

2. Steel Bar Processing and Binding

   • Processing Requirements: Cut and bend steel bars according to design drawings to ensure dimensions comply with specifications.
   • Binding Sequence: Bottom plate bottom steel bars → web and flange plate stirrups → prestressed duct layout → top plate bottom steel bars → installation of top plate corrugated pipes and embedded parts. The prestressed duct is positioned with '#'-shaped steel bars and sealed at both ends.
   • Embedded Part Installation: Strictly arrange prestressed ducts, anchor plates, etc., according to drawings to ensure accurate positioning.

3. Formwork Installation

   • Cleaning and Release Agent: Clean the formwork and apply a release agent before installation.
   • Installation Sequence: Adjust the position and elevation of the bottom formwork → hoist and firmly connect the side formwork → assemble and install the inner formwork in sections, with the bottom supported on steel bar stools and the side plates positioned with steel bars.

4. Concrete Pouring

   • Mixing and Transportation: Mix concrete according to the mix ratio and prevent segregation during transportation.
   • Pouring Method: Advance layer by layer from one end, pouring the bottom plate first and then the web, with the web poured in longitudinal sections and horizontal layers.
   • Vibration Method: Use high-frequency attached vibrators as the primary method, supplemented by immersion vibrators, and use small-diameter vibrators in areas with small feed openings.