Aluminum 6061-T6 vs. Concrete

Compare Aluminum 6061-T6 vs. Concrete strength, stiffness, weight and thermal properties.

Mechanical	Aluminum 6061-T6	Concrete
Yield strength	276MPa1	none (brittle)
Ultimate tensile strength	310MPa1	not sourced
Compressive strength	not sourced	27.6MPa2
Elongation at break	17%1	none (brittle)
Young's modulus (stiffness)	68.3GPa1	design value25.1GPa3
Density	2,700kg/m³1	2,240–2,400kg/m³4
Strength to weight	102kN·m/kg	not sourced
Stiffness to weight	25.3MN·m/kg2.34x higher	10.8MN·m/kg
Poisson's ratio	0.335	0.15–0.26
Shear modulus	25.7GPa2.4x stiffer in shear	10.7GPa
Bulk modulus	67GPa5.2x higher	12.9GPa
Speed of sound	5,030m/s1.53x faster	3,289m/s

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Aluminum 6061-T6	Concrete
Thermal conductivity	167W/m·K1186x more heat through a fin	0.9W/m·K7
Thermal expansion	23.6µm/m·K1	8–12µm/m·K8
100 mm part over a 50 °C swing	118µm growth	50µm growth2.36x less
Specific heat	896J/kg·K1	900J/kg·K9
Heats up and cools (diffusivity)	69mm²/s160x faster	0.431mm²/s
Thermal shock resistance	19,159W/m	not sourced
Melting point	solidus-liquidus582–652°C1	not sourced
Max service temperature	not sourced	65°C6

Thermal conductivity against densityHigher and further left: spreads more heat for its weight

Thermal expansion against thermal conductivityLower and further right: warps less when heated

Try it on a partA sample part to run stress or thermal on, free in your browser	Open in LessCAD	Open in LessCAD

Sources9 documents: Kaiser Aluminum, National Ready Mixed Concrete Association, Federal Highway Administration, U.S. Department of Defense, Oak Ridge National Laboratory, USDA Forest Products Laboratory, National Institute of Standards and Technology

Aluminum 6061-T6: 6061-T6/T651, Kaiser Aluminum typical properties; Poisson from MIL-HDBK-5J
Concrete: Normal-weight portland cement concrete, strength class f'c = 4000 psi (28 MPa) per NRMCA CIP 35; density NRMCA CIP 36; thermal conductivity USDA FPL Wood Handbook; service temperature ORNL/NRC review

1
Alloy 6061 Sheet, Coil & Plate Technical DataKaiser Aluminumarchived copyAluminum 6061-T6 · Yield strength: typical, 0.2% offset, .500 in dia specimenAluminum 6061-T6 · Ultimate tensile strength: typicalAluminum 6061-T6 · Elongation at break: typical, in 4D, 0.500 in dia specimenAluminum 6061-T6 · Young's modulus (stiffness): typicalAluminum 6061-T6 · Density: nominalAluminum 6061-T6 · Thermal conductivity: typical, 20 °CAluminum 6061-T6 · Thermal expansion: typical, mean 20-100 °CAluminum 6061-T6 · Specific heat: typical, at 100 °CAluminum 6061-T6 · Melting point: solidus-liquidus
2
CIP 35: Testing Compressive Strength of ConcreteNational Ready Mixed Concrete Associationarchived copyConcrete · Compressive strength: specified compressive strength class (f'c), not a measured typical
3
LRFD Steel Girder Superstructure Bridge Design Example, Design Step 2: Concrete Deck DesignFederal Highway AdministrationConcrete · Young's modulus (stiffness): design value: AASHTO LRFD 5.4.2.4 applied by FHWA to f'c = 4.0 ksi normal-weight concrete
4
CIP 36: Structural Lightweight ConcreteNational Ready Mixed Concrete Associationarchived copyConcrete · Density: range for normalweight concrete
5
MIL-HDBK-5J, Metallic Materials and Elements for Aerospace Vehicle Structures (2003)U.S. Department of DefenseAluminum 6061-T6 · Poisson's ratio: typical (handbook physical constant)
6
The Effect of Elevated Temperature on Concrete Materials and Structures: A Literature Review (ORNL/TM-2005/553)Oak Ridge National Laboratoryarchived copyConcrete · Poisson's ratio: general range at normal ambient conditions (overall 0.11-0.32)Concrete · Max service temperature: code long-term temperature limit (ASME Code, concrete containments)
7
Wood Handbook (FPL-GTR-282), Chapter 4: Moisture Relations and Physical Properties of WoodUSDA Forest Products LaboratoryConcrete · Thermal conductivity: typical (comparative value)
8
Thermal Coefficient of Portland Cement ConcreteFederal Highway AdministrationConcrete · Thermal expansion: typical range for portland cement concrete (aggregate dependent)
9
Best Practice Guidelines for Structural Fire Resistance Design of Concrete and Steel Buildings (TN 1681)National Institute of Standards and Technologyarchived copyConcrete · Specific heat: typical (NIST guidance for thermal analysis)

Each number points to the document that states it, with the exact basis. Values without a number are computed from the sourced ones. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.

Questions

Mechanical

Which is lighter, Aluminum 6061-T6 or Concrete?

Concrete is lighter: 2,320 kg/m³ against 2,700 kg/m³ for Aluminum 6061-T6.

Which is stiffer, Aluminum 6061-T6 or Concrete?

Aluminum 6061-T6 is stiffer: Young's modulus 68.3 GPa against 25.1 GPa for Concrete, so the same part in Aluminum 6061-T6 deflects less under the same load.

Which is lighter for the same job, Aluminum 6061-T6 or Concrete?

For the same stiffness or strength: Aluminum 6061-T6 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate.

Part that must be	Aluminum 6061-T6	Concrete
Stiff rod or tie (tension)	lighter	2.34x heavier
Stiff beam (bending)	lighter	42% heavier
Stiff panel or plate	lighter	20% heavier

For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).

Thermal

Which conducts heat better, Aluminum 6061-T6 or Concrete?

Aluminum 6061-T6 conducts heat better: 167 W/m·K against 0.9 W/m·K for Concrete.

Which expands less with temperature?

Concrete expands less: 10 µm/m·K against 23.6 µm/m·K for Aluminum 6061-T6.