II. Core Characteristics and Performance Advantages

1. Superior Physical Properties

• Lightweight Design: Density of 1.3-1.5g/cm³, about 1/5 of steel formwork and 1/2 of wooden formwork, enabling single-person handling and reducing construction labor intensity.
• Low Water Absorption: Water absorption <0.5%, ensuring no swelling or deformation in humid environments, suitable for basements, bathrooms, and other wet scenes.
• High Dimensional Stability: Thermal expansion coefficient of 7×10⁻⁵/℃, much lower than metal materials (e.g., steel at 1.2×10⁻⁵/℃), resistant to deformation under high temperature or temperature fluctuations.
• Smooth Surface: Surface flatness error ≤0.5mm, concrete surfaces after demolding can achieve fair-faced effects (flatness ≤2mm), reducing secondary plastering processes.

2. Outstanding Mechanical Properties

• High Strength Bearing: Compressive strength of 20-40MPa (equivalent to C20-C40 concrete), flexural strength of 15-30MPa, capable of withstanding 5-8kPa lateral pressure from concrete.
• Excellent Impact Resistance: Impact strength ≥25kJ/m² at room temperature, not easily damaged by collisions during construction, suitable for complex working conditions.
• Moderate Elastic Modulus: 1000-3000MPa, balancing rigidity and toughness to avoid bending in long-span construction.

3. Stable Chemical Properties

• Strong Weather Resistance: Resistant to acid, alkali, and salt corrosion, with chloride ion diffusion coefficient <10⁻¹²m²/s, suitable for harsh environments like coastal areas and chemical zones.
• Flame Retardancy: Achieves B1-level flame retardancy (oxygen index ≥28%) after adding flame retardants, reducing fire risks at construction sites.

4. Processing and Environmental Advantages

• Flexible Processability: Can be sawed, drilled, nailed, and welded, supporting on-site cutting into special shapes, and compatible with steel/wooden formwork.
• Green Sustainability: Scrap materials can be crushed and granulated for re-production, with zero waste discharge, meeting the "Carbon Peak" policy requirements.

III. Product Categories and Application Scenarios

IV. Application Advantages and Cost Analysis

1. Improved Construction Efficiency

• Installation speed is 30% faster than steel formwork, with single-person daily installation area reaching 20-30㎡ (steel formwork: ~10-15㎡).
• Demolding requires no release agent, and concrete does not stick to the panel, shortening demolding time by 50% and saving cleaning labor.

2. Enhanced Engineering Quality

• Joint gaps ≤1mm, concrete surface flatness error ≤3mm, meeting plaster-free standards, saving decoration costs by 10-15 RMB/㎡.
• Excellent water resistance, no warping after long-term use, avoiding honeycombs and pitting on concrete surfaces.

3. Comprehensive Cost Advantages

• Turnover Times: ≥30 times for flat formwork, ≥40 times for column/beam formwork (wooden formwork: only 5-8 times), reducing single-use cost by 60%.
• Recycling Value: Waste formwork recycling price is ~2000-3000 RMB/ton. Calculated by 30 turnovers, comprehensive cost is 30-40% lower than wooden formwork.

V. Industry Application Cases

• High-rise Buildings: A 30-story residential project in Shenzhen using PVC hollow formwork shortened the construction period by 20 days and saved 280,000 RMB in formwork costs.
• Municipal Engineering: A tunnel project in Hangzhou using reinforced PVC formwork met the concrete surface finish standards, reducing repair costs by 150,000 RMB.
• Green Buildings: A passive house project in Xiong'an New Area using fully recyclable PVC formwork complied with LEED certification requirements, obtaining a 50,000 RMB policy subsidy.

VI. Development Trends and Challenges

• Trend: Driven by policies (e.g., 14th Five-Year Plan for Building Energy Conservation and Green Building Development), the market share of PVC formwork is expected to increase from the current 12% to 20% by 2025.
• Challenges: Initial procurement cost is 30-50% higher than wooden formwork, requiring long-term project turnover to amortize costs; toughness decreases in low temperatures (<-10℃), requiring thermal insulation measures.