Construction Plan for Prefabricated House Beams

The construction plan for prefabricated house beams should cover project overview, construction preparation, construction process, and key construction points, as detailed below:

I. Project Overview

The project involves the construction of a residential community with a total building area of approximately 100,000 square meters, consisting of 12 residential buildings. Prefabricated beams are used as the main structural elements, offering advantages such as rapid construction, stable quality, and good seismic performance.

II. Construction Preparation

1. Technical Preparation

   • Organize technical personnel to study the construction process, familiarize themselves with design drawings, and clarify beam dimensions and material requirements.
   • Prepare the construction plan, complete drawing review, and focus on verifying the specifications of prefabricated components, reserved and embedded positions, and node connection details.
   • Organize expert discussions for critical projects (e.g., single beams weighing ≥10t) and implement them after approval.
   • Review the factory documents of prefabricated components, including concrete strength reports (factory strength ≥75% of design strength) and steel bar mechanical property test reports. Components with incomplete or unqualified documents must not enter the site.
   • Establish a measurement control network with at least 3 elevation control points and 2 plane control points, meeting the accuracy requirements of the Engineering Survey Standard GB50026.

2. Material Preparation

   • Prefabricated beam materials: steel bars, concrete, formwork, etc.
   • Connection materials: grout with a compressive strength of ≥40MPa at 3 days and ≥85MPa at 28 days; sleeve joints with a tensile strength ≥1.1 times the standard value of the steel bars; and bedding grout with a 28-day compressive strength ≥1.1 times the design strength of the prefabricated component concrete.
   • Installation equipment: lifting equipment with a rated capacity ≥1.2 times the maximum component weight, along with supporting equipment such as lifting devices, level gauges, and torque wrenches.

3. Personnel and Site Preparation

   • Establish construction teams, clarify job responsibilities, and conduct safety and technical briefings.
   • Determine storage areas, construct transportation channels, set up lifting equipment, and clear work surfaces.

III. Construction Process

1. Prefabricated Beam Production

   • Steel bar processing: Cut and bind strictly according to design drawings, using hemispherical high-strength mortar spacers.
   • Concrete pouring: Adopt the 'step' pouring method, advancing at 5m intervals to ensure integrity.
   • Curing: Retain same-condition curing test blocks and cure them simultaneously with the beams.

2. Transportation and Lifting

   • Select appropriate transportation vehicles and protect the beams from damage during transit.
   • Inspect lifting equipment and lift the beams to the designated positions as per design requirements.

3. Installation and Acceptance

   • Positioning: Ensure verticality and levelness, with deviations ≤ specification requirements.
   • Connection: Fix the positions of corrugated pipes and anchor plates, and seal the joints with sealing tape.
   • Acceptance: Inspect the appearance (no cracks, honeycombs, etc.), dimensions (length ≤±5mm), and quality (concrete strength, steel bar protective layer thickness).

IV. Key Construction Points

1. Post-tensioning Construction: Includes cleaning the bottom formwork, binding steel bars, installing prestressed ducts, pouring concrete, tensioning, and grouting.
2. Prestressed Construction: Steel strands must be bundled, and tensioning shall be controlled by both force and elongation, with anchoring after stabilization.
3. Grouting: Adopt vacuum grouting technology with a water-cement ratio of 0.26~0.28. Steam curing is required at low temperatures.
4. Concrete End Surface Chiseling: Chisel the wet joints, beam ends, and other parts immediately after formwork removal.
5. Beam and Slab Curing: After formwork removal, use steam pipes connected to sprinkler hoses for curing.