concrete-slab-design

name: concrete-slab-design description: "This skill should be used when an architect or structural designer needs to verify PDF-backed concrete slab requirements such as minimum slab thickness, minimum flexural reinforcement, and shrinkage/temperature reinforcement rules in Taiwan's concrete structure design code." user-invocable: true license: CC-BY-SA-4.0 compatibility: claude-code,opencode,agent-skills metadata: audience: architects region: taiwan class: C regulation: 建築物混凝土結構設計規範

Concrete Slab Design

Overview

Design requirements for reinforced concrete slabs in Taiwan, limited here to items directly verified against the uploaded PDF: minimum slab thickness, minimum flexural steel, and shrinkage/temperature reinforcement rules. Slab-step, opening, and splice details are preserved only as chapter references unless directly transcribed from the source. For cover and splice fundamentals, see concrete-general-requirements.

Section 1: Code Navigation

Structural classification between one-way and two-way slab systems should follow the designer's analysis model and the applicable chapter, rather than an unverified shorthand rule.

Section 2: Minimum Slab Thickness

2.1 One-Way Slab Minimum Thickness (Deflection Control)

For non-prestressed one-way slabs with fy = 420 MPa:

Multiply by (0.4 + fy/700) for fy ≠ 420 MPa. L = clear span length.

Source: 7.3.1.1, Table 7.3.1.1, 7.3.1.1.1.

2.2 Two-Way Slab Minimum Thickness

For non-prestressed two-way slabs, the minimum thickness depends on panel position and column head condition.

Minimum absolute thickness:

• No column head: 125 mm
• With column head: 100 mm

Source: 8.3.1.1, Table 8.3.1.1.

2.3 Practical Minimum for Fire Resistance

Fire-resistance thickness may be governed by 建築技術規則 rather than slab-structure clauses alone. This skill does not restate fire-thickness numbers not transcribed from the governing fire code.

Section 3: Flexural Reinforcement

3.1 Minimum Flexural Reinforcement

For non-prestressed slabs, minimum flexural steel is:

$$A_{s,min} = 0.0018A_g$$

This is the same base ratio used for slab shrinkage and temperature reinforcement.

Source: 7.6.1.1.

3.2 Maximum Bar Spacing

Maximum bar spacing for slab flexural reinforcement:

• Critical sections: min(3h, 450 mm)
• Other sections: min(3h, 450 mm)

Where h = total slab thickness.

Section 4: Temperature and Shrinkage Reinforcement (溫度收縮筋)

4.1 Purpose

Temperature and shrinkage reinforcement controls cracking due to:

• Concrete drying shrinkage (乾縮)
• Seasonal temperature changes
• Creep effects

It is placed perpendicular to the flexural reinforcement in one-way slabs, and in both directions in slabs with equal reinforcement.

Key concept: Temperature/shrinkage steel is NOT structural — it does not increase load capacity. Its sole purpose is crack width control.

4.2 Minimum Temperature/Shrinkage Reinforcement Ratio

$$\rho_{t&s} = \frac{A_s}{b \cdot h}$$ (gross slab area)

Source: 7.6.4.1, 7.7.6.2.1.

4.3 Maximum Spacing for Temperature/Shrinkage Bars

Maximum spacing: min(5h, 450 mm)

Section 5: Development, Splice, and Opening Checks

This audit pass did not verify any slab-specific high-low-slab rule, opening-reinforcement rule, or numeric splice-length rule directly from the PDF. Therefore, this skill intentionally does not preserve those items as technical requirements.

When a project needs those checks, the AI should:

• resolve the applicable slab clause from the PDF if one exists,
• otherwise fall back to the general rebar development and splice clauses in Chapters 25.4 and 25.5,
• and avoid inventing slab-step or opening details not explicitly supported by the source.

Section 7: AI Design Check Table — Slab

Section 8: MCP Tool Examples

# Search for slab minimum thickness
taiwan-building-code_search_building_code(query="版 最小厚度 撓度 one-way two-way", limit=10)

# Search for temperature/shrinkage reinforcement
taiwan-building-code_search_building_code(query="溫度收縮鋼筋比 版 最小量", limit=10)

# Search for slab opening requirements
taiwan-building-code_search_building_code(query="版 開口 開孔 補強 鋼筋", limit=10)

# Search for high-low slab (if referenced specifically in Taiwan code)
taiwan-building-code_search_building_code(query="高低版 搭接 版高差 段差", limit=10)

# Official interpretations
taiwan-building-code_search_building_interpretations(query="版 高低差 搭接 斜筋補強")

Additional Resources

• General requirements (cover, development length, lap splice fundamentals): concrete-general-requirements
• Beam design (connected to slab as T-beam): concrete-beam-design