Doc #023 — Computed Reference Data
Generated fromscripts/generate_materials_properties.py.
All values are typical/nominal. Engineer to site conditions. AS/NZS standards apply.
1. Structural Materials
Density, strength, stiffness, and thermal properties for materials likely available in a post-disruption NZ context. NZ Availability: A = abundant domestic supply, B = available with some supply chain, C = limited/import-dependent, D = unavailable or trace.
1.1 Metals
| Material | Density (kg/m³) | Tensile Strength (MPa) | Yield Strength (MPa) | Young’s Modulus (GPa) | Thermal Conductivity (W/m·K) | Thermal Expansion (µm/m·°C) | NZ Availability | Typical Uses |
|---|---|---|---|---|---|---|---|---|
| Mild steel (AS/NZS 3678 Gr 250) | 7 850 | 410 | 250 | 200 | 50 | 12 | A | Structural framing, fabrication |
| Structural steel Gr 300 (NZ Steel) | 7 850 | 440 | 300 | 200 | 50 | 12 | A | Beams, columns, portals |
| Structural steel Gr 350 | 7 850 | 480 | 350 | 200 | 50 | 12 | A | Heavy structural, bridges |
| Stainless steel 304 | 8 000 | 515 | 205 | 193 | 16 | 17.2 | B | Food equipment, coastal fittings |
| Stainless steel 316 | 8 000 | 515 | 205 | 193 | 16 | 16.0 | B | Marine, chemical plant |
| Cast iron (grey) | 7 200 | 150 | — | 100 | 52 | 10.8 | B | Pumps, pipe fittings, cookware |
| Aluminium 6061-T6 | 2 700 | 310 | 276 | 69 | 167 | 23.6 | B | Light structures, transport, extrusions |
| Copper (annealed) | 8 960 | 220 | 70 | 117 | 385 | 17.0 | B | Electrical, plumbing, heat exchangers |
| Brass (CZ106, 70/30) | 8 500 | 350 | 100 | 101 | 120 | 19.9 | B | Valves, fittings, bearings |
| Bronze (phosphor, C51000) | 8 800 | 430 | 130 | 105 | 70 | 17.8 | C | Bushings, marine hardware, bearings |
| Zinc (rolled) | 7 130 | 130 | 110 | 97 | 116 | 31.0 | B | Galvanising, die-casting, roofing |
| Lead | 11 340 | 17 | 12 | 16 | 35 | 28.9 | B | Flashing, radiation shielding, ballast |
| Tin | 7 290 | 20 | 9 | 47 | 67 | 23.0 | C | Soldering alloy, tin-plate, coatings |
Sources: NZ Steel product datasheets; AS/NZS 3678:2016; AS/NZS 1734 (aluminium); MatWeb typical values.
1.2 Timber — NZ Species and Engineered Products
Timber properties vary with moisture content (MC). Green = freshly felled; Dry = air-dried to ~15% MC. Strength class (SC) refers to NZS 3603:1993 stress grades.
| Material | Density (kg/m³) | Tensile Strength // grain (MPa) | Compressive Strength // grain (MPa) | Modulus of Elasticity (GPa) | Thermal Conductivity (W/m·K) | Thermal Expansion (µm/m·°C) | NZ Availability | Typical Uses |
|---|---|---|---|---|---|---|---|---|
| Radiata pine — green | 550 | 22 | 20 | 8.0 | 0.14 | 3–5 | A | Rough framing, temporary works |
| Radiata pine — dry (SC8) | 480–550 | 33 | 25 | 10.0 | 0.12 | 3–5 | A | Framing, joinery, general construction |
| Radiata pine — H3.2 treated | 500–570 | 30 | 24 | 9.5 | 0.13 | 3–5 | A | External framing, decking, fencing |
| Douglas fir (Pseudotsuga menziesii) | 530 | 38 | 30 | 13.0 | 0.14 | 3–5 | B | Heavy framing, beams, structural |
| Macrocarpa (Cupressus macrocarpa) | 560 | 34 | 28 | 9.5 | 0.13 | 3–5 | B | Outdoor furniture, posts, cladding |
| Rimu (Dacrydium cupressinum) | 600 | 45 | 38 | 12.0 | 0.16 | 4–6 | C | Furniture, flooring (existing stock only) |
| Native hardwoods (general avg.) | 700–900 | 55 | 50 | 13.0 | 0.18 | 4–6 | C | Heavy posts, tool handles, turnery |
| LVL (laminated veneer lumber) | 570–620 | 45 | 35 | 13.2 | 0.14 | 3–5 | A | Beams, lintels, portal frames |
| Structural plywood (F8) | 550 | 24 | 20 | 9.5 | 0.13 | 3–5 | A | Flooring, bracing, formwork |
Sources: NZS 3603:1993 Timber Structures Standard; Scion Research timber property data; Wood Solutions NZ species guide.
1.3 Concrete
| Material | Density (kg/m³) | Compressive Strength f’c (MPa) | Tensile Strength (MPa) | Young’s Modulus (GPa) | Thermal Conductivity (W/m·K) | Thermal Expansion (µm/m·°C) | NZ Availability | Typical Uses |
|---|---|---|---|---|---|---|---|---|
| Normal weight concrete (25 MPa) | 2 350 | 25 | 2.5 | 26 | 1.7 | 10 | A | Slabs, footings, walls |
| Normal weight concrete (30 MPa) | 2 400 | 30 | 2.9 | 29 | 1.8 | 10 | A | Structural elements, bridges |
| Lightweight concrete (pumice agg.) | 1 600 | 20 | 2.0 | 14 | 0.8 | 9 | B | Non-structural walls, insulation |
| High-strength concrete (50 MPa+) | 2 450 | 50–80 | 4.5 | 38 | 2.0 | 10 | B | Columns, prestressed elements |
Sources: NZS 3101:2006 Concrete Structures Standard; cement.org.nz.
1.4 Masonry
| Material | Density (kg/m³) | Compressive Strength (MPa) | Tensile/Flexural Strength (MPa) | Young’s Modulus (GPa) | Thermal Conductivity (W/m·K) | Thermal Expansion (µm/m·°C) | NZ Availability | Typical Uses |
|---|---|---|---|---|---|---|---|---|
| Clay brick (fired) | 1 800–2 000 | 20–40 | 0.5–1.5 | 15–20 | 0.6–0.9 | 5–7 | B | Walls, chimneys, paving |
| Concrete block (hollow, 15 MPa) | 1 200–1 500 | 15 | 0.8 | 10–15 | 0.7 | 10 | A | Load-bearing walls, retaining |
| Natural stone (greywacke, NZ) | 2 600–2 700 | 80–150 | 5–10 | 35–60 | 2.5–3.5 | 8–10 | B | Foundations, walls, paving |
| Natural stone (limestone/marble) | 2 500–2 700 | 50–100 | 3–7 | 50–70 | 2.0–3.0 | 8–9 | B | Walls, cladding |
Sources: AS/NZS 4455 Masonry Units; NZS 4230:2004 Masonry Structures.
1.5 Composites and Alternative Materials
| Material | Density (kg/m³) | Tensile/Flexural Strength (MPa) | Young’s Modulus (GPa) | Thermal Conductivity (W/m·K) | Thermal Expansion (µm/m·°C) | NZ Availability | Typical Uses | |
|---|---|---|---|---|---|---|---|---|
| Fibreglass (GFRP, woven) | 1 800 | 200–300 | 15–30 | 0.3 | 20–35 | B | Tanks, boats, roofing panels | |
| Carbon fibre (CFRP, UD) | 1 600 | 1 000–1 500 | 70–140 | 0.8 | −1 to 0 | C | Aerospace, high-perf. structures | |
| Bamboo (Phyllostachys, dry) | 600–900 | 150–300 | 10–20 | 0.17 | 6 | B | Scaffolding, light framing, furniture | |
| Rammed earth (stabilised) | 1 700–2 100 | 0.5–3 (comp.) | 0.3–0.8 | 0.8–1.2 | 11 | A | Walls, floors, thermal mass | |
| Cob (clay/straw/sand) | 1 600–1 900 | 0.3–1.5 (comp.) | 0.3–0.6 | 0.6–1.0 | 10–12 | A | Walls, ovens, storage structures |
Sources: Clarke (2002) Rammed Earth; BRANZ earthen construction guidance; bamboo.org property data.
2. Fastener Reference
Capacities are indicative for standard service conditions in NZ softwood framing unless noted. Always verify against NZS 3603 (timber) or AS/NZS 4600 / AS 4100 (steel).
| Fastener Type | Material | Sizes Available | Tensile Capacity (kN) | Shear Capacity (kN) | NZ Availability | Notes |
|---|---|---|---|---|---|---|
| Round wire nail | Mild steel, galv. | 30–150 mm (2.5–4.5 mm dia.) | 0.4–3.5 | 0.3–2.5 | A | Low withdrawal in end grain |
| Jolt-head nail (gun nail) | Bright / hot-dip galv. | 50–90 mm | 0.5–3.0 | 0.4–2.2 | A | Pneumatic framing standard |
| Wood screw (bugle head) | Zinc-plated / SS | 25–150 mm (No. 8–14) | 1.5–8.0 | 1.0–5.0 | A | Superior withdrawal to nails |
| Structural screw (SDS/LBS type) | Grade 10.9, zinc | 9–300 mm | 5–40 | 4–30 | A | Replace bolts in many cases |
| Coach screw | Hot-dip galv. steel | M8–M20, 50–300 mm | 10–65 | 8–50 | A | Heavy timber connections |
| Bolt, Grade 4.8 | Carbon steel | M6–M30 | 8–190 | 5–110 | A | General structural bolting |
| Bolt, Grade 8.8 | High-tensile steel | M6–M36 | 18–410 | 10–240 | A | High-load structural bolting |
| Timber connector (split ring) | Malleable iron | 65 mm, 100 mm | — | 15–45 | B | Roof trusses, heavy timber |
| Timber connector (shear plate) | Malleable iron / steel | 65 mm, 100 mm | — | 15–60 | B | Bolted timber-to-timber |
| Pop rivet (blind) | Aluminium / steel | 3.2–6.4 mm dia. | 0.5–5.0 | 0.4–4.0 | A | Sheet metal, non-structural |
| Structural rivet (HSFG) | High-tensile | M16–M24 | 50–150 | 45–130 | B | Steel bridges, heritage repair |
Sources: NZS 3603:1993 Table 4; Simpson Strong-Tie NZ product data; AS 4100:1998 Steel Structures.
3. Adhesive and Sealant Properties
Performance values are typical at 23°C unless stated. Shelf life assumes sealed, cool-dark storage.
| Type | Bond Strength (MPa) | Gap-Filling | Water Resistance | Temperature Range (°C) | Cure Time (full) | Shelf Life | NZ Availability | Primary Uses |
|---|---|---|---|---|---|---|---|---|
| PVA (polyvinyl acetate) | 5–10 | Poor | Low | −10 to +60 | 24 h | 1–2 yr | A | Timber joints, paper, textiles |
| Cross-linked PVA (Type II) | 8–12 | Poor | Moderate | −10 to +80 | 48 h | 1–2 yr | A | Exterior timber (below waterline) |
| Epoxy (2-part, standard) | 20–40 | Good | Excellent | −50 to +120 | 7 d | 2–3 yr | A | Metal, concrete, fibreglass bonding |
| Epoxy (2-part, marine grade) | 25–50 | Excellent | Excellent | −50 to +150 | 7 d | 2 yr | B | Boat repair, wet-area structural |
| Polyurethane adhesive (1-part) | 10–20 | Excellent | Very good | −40 to +90 | 24–72 h | 1 yr | A | Timber, concrete, foam, mixed subs. |
| Construction adhesive (solvent) | 5–12 | Good | Good | −20 to +80 | 24 h | 1 yr | A | Cladding, linings, non-structural |
| Cyanoacrylate (super glue) | 10–25 | Poor | Poor | −55 to +80 | 5–60 s | 1 yr | A | Rigid bonds, small parts, skin cuts |
| Contact cement (neoprene) | 3–8 | None | Good | −20 to +70 | Instant (dry) | 1 yr | A | Laminates, rubber, leather bonding |
| Silicone sealant (neutral cure) | 1–3 (flex) | Excellent | Excellent | −60 to +200 | 24 h skin | 1 yr | A | Glazing, sanitary, weathersealing |
| Silicone sealant (acetoxy cure) | 1–3 (flex) | Excellent | Excellent | −60 to +180 | 24 h skin | 1 yr | A | General weathersealing (avoid metals) |
Sources: Selleys product datasheets; Sika NZ technical data; adhesive.org typical property ranges.
4. Substitution Guide
Where preferred materials are unavailable, the following alternatives reduce (but do not eliminate) functional performance. Performance penalties must be assessed against the specific application.
| If You Need | But Cannot Obtain | Use Instead | Performance Penalty | Feasibility |
|---|---|---|---|---|
| Structural mild steel | Steel (supply disruption) | Wrought iron (salvage) | Lower yield (~200 MPa), more brittle, labour-intensive fabrication | B |
| Structural mild steel | Steel (supply disruption) | Heavy timber (LVL/glulam) | Reduced span, moisture-sensitive, requires fire protection | A |
| Structural mild steel | Steel (supply disruption) | Reinforced concrete | Greatly increased weight, formwork required, long cure time | A |
| Aluminium sections | Aluminium (import halt) | Structural steel | 3× heavier; re-engineer section sizes; no corrosion advantage | A |
| Aluminium sections | Aluminium (import halt) | Timber (treated) | Moisture limits span; lower modulus; replace corrosion concern with rot concern | A |
| Copper wire (electrical) | Copper (shortage) | Aluminium wire (AA8000) | Requires larger cross-section (+56% area); special terminations; fire risk if under-terminated | B |
| PVC/plastic pipe | Plastic pipe (unavailable) | Fired clay/vitrified pipe | Brittle; requires skilled jointing; heavy; no flexibility in earthquake zones | B |
| PVC/plastic pipe | Plastic pipe (unavailable) | Concrete pipe (spun) | Heavy; requires machinery; adequate for gravity drainage | B |
| PVC/plastic pipe | Plastic pipe (unavailable) | Split timber (lined with clay) | Very short lifespan; emergency only; rot risk | C |
| Portland cement concrete | Cement (supply disruption) | Lime mortar (hydraulic lime) | Lower strength (~5 MPa); slow cure; adequate for masonry, not RC | A |
| Portland cement concrete | Cement (supply disruption) | Pozzolanic cement (volcanic ash + lime) | Slower set; 70–80% strength; NZ volcanic ash available | B |
| Float glass (windows) | Glass (import halt) | Mica sheets (muscovite) | Poor clarity; brittle; limited to small panes; NZ deposits limited | C |
| Float glass (windows) | Glass (import halt) | Oiled paper / waxed cloth | No structural value; UV degrades; emergency weatherproofing only | D |
| Float glass (windows) | Glass (import halt) | Polycarbonate sheet | Good clarity; UV yellows; scratches; available if plastics supply intact | B |
| Rubber (seals, belts, tyres) | Rubber (import halt) | Vegetable-tanned leather | Lower elasticity; absorbs moisture; adequate for static seals, belts | B |
| Rubber (seals, belts, tyres) | Rubber (import halt) | Woven fibre / canvas (oiled) | Very limited; emergency flat-belt drives only; degrades under load | C |
Feasibility ratings: A = practical with moderate skill/resources; B = feasible with significant effort; C = marginal / emergency use only; D = not recommended except last resort.
5. Corrosion Compatibility — Galvanic Series (NZ Coastal/Marine Context)
When two dissimilar metals are in electrical contact in the presence of an electrolyte (salt spray, condensation, soil moisture), the more active (anodic) metal corrodes preferentially. NZ coastal zones extend up to 500 m from shoreline; tidal splash zones are more aggressive.
Galvanic Series (most active → least active, anodic → cathodic):
| Rank | Metal | Potential vs. SCE (approx. V) | NZ Coastal Risk |
|---|---|---|---|
| 1 (most anodic) | Zinc (galvanising) | −1.00 | Sacrificial — corrodes to protect steel |
| 2 | Aluminium alloys | −0.75 | Corrodes if paired with copper/steel in wet |
| 3 | Mild steel / cast iron | −0.50 | Corrodes; protect with coating or zinc |
| 4 | Lead | −0.40 | Moderate corrosion resistance |
| 5 | Tin | −0.25 | Slow corrosion; good as coating on steel |
| 6 | Brass (70/30) | −0.10 | Generally compatible; dezincifies in seawater |
| 7 | Bronze (phosphor) | −0.05 | Good marine resistance |
| 8 | Copper | 0.00 | Reference; very good marine resistance |
| 9 | Stainless steel 304 | +0.10 | Risk of pitting in crevice/saltwater |
| 10 (most cathodic) | Stainless steel 316 | +0.18 | Best common marine stainless |
Compatibility Decision Table:
| Connection | Risk Level | Mitigation Required |
|---|---|---|
| Zinc-coated steel + mild steel | Low | None (zinc is sacrificial) |
| Aluminium + mild steel (wet) | High | Isolate with neoprene/sealant; use SS fasteners |
| Copper + mild steel (wet) | High | Avoid or fully isolate; steel corrodes rapidly |
| Copper + stainless steel | Low-Med | Acceptable; monitor in splash zones |
| Brass fittings on copper pipe | Low | Acceptable; dezincification risk in hot water |
| Stainless 304 + 316 | Negligible | No isolation needed |
| Lead flashing + aluminium | Medium | Isolate with bituminous tape |
| Galv. steel + aluminium (dry) | Low | Acceptable in interior dry conditions |
| Galv. steel + aluminium (coastal wet) | High | Isolate; aluminium sacrifices |
Sources: AS 2331 Metallic coating tests; BRANZ Bulletin 388 (Corrosion in NZ Buildings); HERA Steel Design & Construction Bulletin.
6. NZ Materials Production
Domestic production capacity determines post-disruption material availability. Import dependency column reflects raw material inputs, not finished product.
| Material | NZ Producer | Annual Output (approx.) | Location | Import Dependency (Raw Materials) | Notes |
|---|---|---|---|---|---|
| Structural steel (rod, coil, bar) | NZ Steel Ltd | ~650 000 t/yr steel | Glenbrook, South Auckland | Ironsand (domestic); coal (domestic/imported); lime (domestic) | Unique ironsand-to-steel process; integrated steelmill |
| Steel reinforcing bar | Pacific Steel (subsidiary NZ Steel) | ~200 000 t/yr rebar | Otahuhu, Auckland | NZ Steel billet feed | Recycled scrap supplemented |
| Structural steel sections | Imported (resold by Metalcraft, Fletchers, etc.) | — | NZ ports | 100% import (AUS, Asia) | No domestic section rolling mill |
| Aluminium products | No domestic smelting | — | — | 100% import | Tiwai Point smelter closed 2024; all aluminium now imported |
| Copper products | No domestic mining/smelting | — | — | 100% import | Copper recycled domestically at small scale |
| Portland cement | Golden Bay Cement (Holcim NZ) | ~900 000 t/yr | Portland, Northland | Limestone (domestic); coal/gas (partly imported) | Only NZ cement producer |
| Concrete aggregate | Multiple quarry operators | ~20 000 000 t/yr | Nationwide | Domestic | Greywacke, limestone, scoria quarries |
| Radiata pine timber | Multiple sawmills (Woodco, Red Stag, etc.) | ~5 000 000 m³/yr log | Central NI, Nelson, Canterbury | Domestic plantation | 90%+ of structural softwood |
| Engineered timber (LVL, glulam) | Red Stag Timber, Nelson Pine | ~500 000 m³/yr | Rotorua, Nelson | Domestic logs | Export-oriented; domestic supply available |
| Structural plywood | Carter Holt Harvey (Plyco) | ~150 000 m³/yr | Tokoroa, Kawerau | Domestic radiata veneer | Some import competition |
| Clay bricks | Firth (Fletcher Building), Brickworks | ~50 000 000 units/yr | Various | Domestic clay | Capacity reduced; imports increasing |
| Concrete masonry block | Firth, Allied Concrete, others | ~100 000 000 units/yr | Nationwide | Domestic aggregate + imported cement | Distributed production |
| Float glass | None (no NZ glass plant) | — | — | 100% import (AUS, Asia) | Critical import dependency |
| PVC/plastic pipe | Marley NZ, Iplex | ~30 000 t/yr | Auckland, Palmerston North | PVC resin 100% imported | Downstream fabrication only |
Sources: NZ Steel Annual Report 2023; MPI Wood Availability Forecasts 2022; Holcim NZ; Stats NZ Manufacturing statistics; MBIE Building and Construction Sector Report.
Notes on Data Reliability
- All mechanical property values are nominal/typical. Actual values depend on heat treatment, product form, supplier, and testing conditions.
- Timber properties are highly species- and moisture-content-dependent. Always test critical members.
- NZ Availability ratings reflect the 2024 baseline scenario (grid intact, ports functional). In a supply-chain disruption scenario, ratings for import-dependent materials shift toward D.
- This table does not constitute engineering advice. Engage a chartered professional engineer for any structural, pressure, or life-safety application.
Standards Referenced
- AS/NZS 3678:2016 — Structural steel — Hot-rolled bars and sections
- NZS 3603:1993 — Timber Structures Standard
- NZS 3101:2006 — Concrete Structures Standard
- NZS 4230:2004 — Design of Reinforced Concrete Masonry Structures
- AS/NZS 4455 — Masonry Units and Segmental Pavers
- AS 4100:1998 — Steel Structures
- AS/NZS 4600:2018 — Cold-Formed Steel Structures
- AS 2331 — Metallic and related coatings
- BRANZ Bulletins: 388 (Corrosion), 530 (Adhesives), 574 (Timber)
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scripts/generate_materials_properties.py.