How to Make Cement Components for Prefabricated Houses

The manufacturing of cement components for prefabricated houses involves four core processes: material preparation, mold making, pouring and curing, and assembly and transportation. The specific procedures are as follows:

1. Material Preparation and Inspection

1. Cement: Select P.O42.5 ordinary Portland cement, which should be fresh and free of lumps. Before entering the site, it must pass an soundness test to ensure stable cement quality.
2. Aggregates: Use medium-coarse sand with a mud content of ≤3%. The main particle size of crushed stone is 5-20 millimeters, accounting for 60%, which facilitates the dense formation of concrete.
3. Reinforcing Bars: Choose HRB400 deformed steel bars with diameters ranging from 8 to 14 millimeters. Adjust the specifications according to load-bearing requirements. Upon arrival, test the tensile strength.
4. Admixtures and Auxiliary Materials: Add early strength agents, water reducers, etc., as needed. Prepare cement mortar and waterproof materials for joints, and equip with mixers, vibrators, rebound hammers, and other equipment.

2. Mold Making and Verification

1. Mold Material: Traditional wooden molds are gradually being replaced by steel molds welded from 5-millimeter-thick steel plates, with the inner walls coated with release agents to prevent adhesion.
2. Functional Design: Pre-embed water and electricity pipeline positioning devices in the mold, and fix plastic-steel frames at window positions to ensure the functional integrity of the components.
3. Precision Control: Verify that the diagonal deviation of the mold is ≤3 millimeters. Treat the corner joints with sealant to prevent leakage during pouring.

3. Pouring and Curing Processes

1. Reinforcement Layout: Bind the main and stirrup bars according to the design drawings, and use iron wires to cross-fix key nodes, forming a stable framework.
2. Concrete Mixing: Use a forced mixer for mixing, with a water-cement ratio controlled between 0.45-0.5 to ensure a balance between fluidity and strength.
3. Vibration Process: Insert the vibrator to the bottom of the mold, vibrating each spot for 20-30 seconds to eliminate air bubbles and enhance density.
4. Curing Conditions: After pouring, cover with plastic film for moisture retention. In winter, activate steam curing equipment to maintain an ambient temperature of ≥20°C. Normal-temperature curing for 7 days achieves 70% of the design strength, and full compliance is reached after 28 days.
5. Quality Inspection: Test the wall strength with a rebound hammer. After passing the inspection, use a gantry crane to remove the component from the mold and trim any burrs.

4. Assembly and Transportation Specifications

1. Transportation Protection: Use special flatbed trucks for transportation, and install rubber pads between modules to prevent collision damage.
2. On-site Installation: Verify the positions of foundation embedded parts, connect the walls to the foundation with high-strength bolts, and inject special repair mortar into the joints to ensure structural stability.

By strictly controlling the material, mold, pouring, and assembly processes, efficient production and safe application of cement components for prefabricated houses can be achieved.