Compaction

CE

Loose Thickness ↔ Compacted Thickness Calculator

Compute the required loose (uncompacted) thickness to achieve a specified compacted thickness by removing voids (change in void ratio). Designed for civil engineers — stepwise breakdown included.

Compacted thickness (T_c)

mm m cm

Initial void ratio (e_i) Final void ratio after compaction (e_f)

Core formula

Tl = Tc × (1 + ei) / (1 + ef)

Δ = Tl - Tc % Increase = Δ / Tc

Loose thickness (T_l)

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Increase / bulking (Δ)

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Percentage increase

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Explanation & worked example

Derivation uses conservation of solids: volume of solids (V_s) remains constant. Bulk volume V = V_s(1+e). For unit plan area, thickness = bulk volume.

Worked example

Provide input and press Calculate to see a worked example here.

Options / remarks

• You may input voids either as void ratio e (recommended) or convert porosity n to e using e = n / (1 - n).
• Units: calculator keeps units consistent — the result is in the same unit as the input compacted thickness.
• Assumes no loss of solids (no segregation, trimming, or material loss during placement).
• For field practice, account for trimming, settlement, and moisture effects as appropriate.

_l) Compacted (T_c) Unit area = 1 m² (plan)

Full stepwise calculation

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Prepared as if by a highly learned civil engineer — shows derivation, checks and downloadable HTML.