How to Build a Model of a Prefabricated Slab House

The process of building a model of a prefabricated slab house mainly consists of four steps, as follows:

First, construct a hollow model using wooden planks. Select wooden planks of appropriate thickness and uniform texture based on the actual dimensions and shape of the prefabricated slab. Join the planks into a hollow frame structure using nails or screws. This step requires ensuring the dimensional accuracy of the model, especially the proportions of length, width, and thickness, which should match those of the actual prefabricated slab. Additionally, the stability of the frame directly affects the safety of subsequent operations. For example, when building a model of a prefabricated slab that is 3 meters long and 0.5 meters wide, use wooden planks to enclose a hollow rectangular prism of the corresponding dimensions and reinforce the corners to prevent deformation.

Next, arrange steel bars within the hollow section. Steel bars are the core material for enhancing the structural strength of the prefabricated slab. Typically, threaded steel bars or plain round steel bars with a diameter of 6-8 millimeters are selected. When arranging them, follow the principle of 'crisscrossing': first lay the main bars along the length of the prefabricated slab (usually 2-3 bars), then lay the distribution bars along the width (with a spacing of about 15-20 centimeters), and finally tie the intersections firmly with wire. The arrangement of steel bars should ensure a 2-3 centimeter protective layer from the edges of the model to prevent rusting caused by direct exposure to air and to ensure that the cement can completely envelop the steel bars to form a protective shell.

Then, fill the hollow section with cement. Select ordinary Portland cement with a grade not lower than C30. Prepare mortar with a ratio of 1:2.5 (cement: sand) and add an appropriate amount of water-reducing agent to improve fluidity. During grouting, vibrate in layers: first pour cement to about one-third of the height, use a vibrating rod or wooden mallet to lightly tap the outside of the model to expel air bubbles, and then continue pouring until completely filled. This step requires controlling the grouting speed to avoid cement stratification or displacement of steel bars due to excessive speed, while ensuring that the top of the model is flat to facilitate subsequent demolding.

Finally, wait for the cement to dry and then knock away the wooden planks. The initial setting time of cement is about 3-5 hours, and the final setting time is about 10-12 hours, but it takes 28 days to fully reach the design strength. In practice, to improve efficiency, demolding can begin 24 hours after grouting (when the cement strength reaches more than 50% of the design value): first lightly tap the edges of the model with a hammer to separate the wooden planks from the cement, and then gradually remove the planks. After demolding, place the prefabricated slab model in a cool, ventilated place for further curing for 7 days, regularly spraying water to keep the surface moist and prevent cracking due to rapid drying.