Units in materials management: Bulk density (unit weight) of aggregates at the stockyard or in batching is typically expressed in which unit?

Introduction / Context:
Bulk density of aggregates is needed for volumetric batching, truck payload checks, and storage calculations. Consistent units prevent errors in converting between weight and volume on site.

Given Data / Assumptions:

• Bulk density measured in a container by filling and weighing.
• Moisture and compaction condition stated (loose or rodded).
• Construction site practice favors SI units.

Concept / Approach:
In SI practice, bulk density is expressed as kg/m^3. While g/cm^3 or tonnes/m^3 are dimensionally equivalent, routine batching and mix design documentation typically use kg/m^3 to align with cement and water units and ready-mix ticketing.

Step-by-Step Solution:
Select the SI unit used in mix design tables and stock records → kg/m^3.Recognize equivalence: 1 g/cm^3 = 1000 kg/m^3, 1 tonne/m^3 = 1000 kg/m^3.Prefer kg/m^3 for standardization.

Verification / Alternative check:
Material datasheets and codes list typical bulk densities (e.g., sand ~1500–1700 kg/m^3) in kg/m^3.

Why Other Options Are Wrong:
They are not the most commonly adopted unit in site batching documentation, even if convertible.

Common Pitfalls:
Mixing up dry-rodded vs loose densities; neglecting moisture correction when converting volume to mass.

Final Answer:
kg per cubic metre.