The installation of full-body PC imitation stone brick requires a comprehensive process management system, from base preparation, material preparation, paving techniques, to post-treatment maintenance. The key to preventing hollowing is ensuring sufficient adhesion between the brick and the base. Before construction, the base must be thoroughly cleaned, using a steel brush to remove impurities such as dust and oil. Cracks or loose areas in the base should be repaired and leveled with cement mortar, ensuring the leveling layer has a flatness tolerance of no more than 5mm. For concrete bases with high water absorption, moisten them with water the day before construction and spray them again the next day before paving to prevent excessive water absorption and rapid dehydration of the bonding layer.
Material selection and mix ratio directly impact bond strength. Use ordinary Portland cement with a grade of 325 or higher. Sand should be sieved to remove lumps. Medium-grade sand with a mud content below 3% is recommended. The bonding layer mortar ratio is typically 1:2 to 1:3 cement:sand. The dryness and wetness should be controlled during mixing, ensuring that the mortar forms a ball when held in the hand and falls apart when dropped. Too thin mortar can cause the full-body PC imitation stone bricks to slip, while too dry mortar will not adequately fill gaps. For areas with heavy vehicle traffic, an appropriate amount of polymer additives can be added to the mortar layer to improve flexural strength and durability.
The paving process is critical to preventing hollowing. When using the "double-sided screeding method," mortar should be applied simultaneously to the back of the full-body PC imitation stone bricks and the base layer, maintaining a thickness of 10-15mm to ensure an even bondline with no gaps. During paving, gently tap the bricks from the center outward to ensure the mortar fully penetrates the joints. Use a level to check for smoothness. Verify overall smoothness with a 2-meter ruler every 3-5 bricks. For large paving areas, the "skip-laying" method is recommended: paving the center first and then expanding outwards to avoid warping of the bricks due to stress concentration in the base layer.
Gap treatment helps prevent hollowing. The recommended gap width for full-body PC imitation stone bricks is 3-8mm. Too narrow a gap can easily cause cracking and compression due to thermal expansion and contraction, while too wide a gap can cause cracks due to mortar shrinkage. Grouting should be performed after the initial setting of the bonding layer. First, fill the gap with dry-mixed cement mortar or a specialized grout to 2/3 of the depth, then compact and smooth it with steel bars to ensure a tight gap without voids. After grouting, any remaining mortar on the brick surface must be cleaned promptly to prevent "black edges" from drying and affecting the appearance.
Controlling the construction environment is essential for ensuring paving quality. In winter, when temperatures drop below 5°C, moisture in the mortar can easily freeze, causing expansion and damaging the bonding structure. During these times, construction should be suspended or heating measures should be applied. During high summer temperatures, construction should be avoided at noon to prevent the mortar from drying out too quickly. During rainy days, the work surface must be covered with tarpaulin to prevent mortar loss caused by rainwater erosion. Ensure that no water accumulates in the base layer to prevent dilution and weakening of the mortar.
Maintenance and maintenance are crucial to maintaining a solid paving result. Within 12 hours of paving completion, the brick surface must be covered with sawdust or colored cloth to prevent trampling or heavy objects from rolling on it. For 48 hours, spray the bricks with water every six hours to maintain moisture in the joints and promote hydration of the mortar. If localized hollowing is discovered during curing, the bricks must be lifted immediately, the laitance at the bottom removed, and the tiles re-laid. Direct cement grouting is strictly prohibited to prevent secondary hollowing caused by improper bonding surface preparation.
Full-body PC imitation stone brick paving construction requires a closed-loop quality control system of "prevention-control-correction." From refined base layer preparation to standardized material mixes, from standardized paving techniques to systematic maintenance management, every step must strictly adhere to technical specifications. By implementing a full-process quality traceability system and dynamically monitoring key indicators such as hollowing rate and flatness, the hollowing rate can be effectively controlled within 1%, ensuring that the paving project achieves the expected effect of "flatness, density and beauty".
