FORM TL-3112 · CALIFORNIA TEST 375

Density / Relative Compaction.
Calculated.

The Caltrans in-situ asphalt concrete workbook, with every formula wired. Random stations, count ratios, density, RC% — done the moment you type the nuclear reading.

Form
TL-3112
Method
CT-375
Units
English (ft, pcf)
Format
.XLSX · Field-ready
01 / What it computes

Every cell
audited.

The workbook mirrors TL-3112 (Rev. 02/04) line-for-line and runs every calculation the form requires. You fill nuclear readings and project data. The sheet does the arithmetic — and the policing.

01

Random locations, per spec

Generates the 10 random numbers and test-site math CT-375 requires. No hand-rolling, no spreadsheets on a napkin.

COLS G · H · ROWS 28–29
02

Station & offset math

Longitudinal I = D × G, Station I + B, Transverse E × H. Rounded to whole-number stations the way the form wants them.

LINES I · J · K
03

Count ratio → density

Field count divided by standard count (L / A), density read through your gauge's calibration, rounded to 0.01 g/cc.

LINES L · M · N
04

Correlation & LTMD

Applies the correlation factor to your FTMD (R × S) to land on LTMD, and carries the (4/3/2025)-style dated reference through every sublot.

LINES R · S · T
05

Relative Compaction %

Computes RC = (Q / T) × 100 to the nearest 0.1% exactly as CT-375 specifies, averaged and flagged against the 95% LTMD threshold.

LINE U
06

Multi-lift, multi-sublot

Built for conventional 0.20 ft and thin-lift 0.18 ft runs on the same project, with field-note space for transverse moves (e.g. sta. 699+42).

TABS CT-375 · TABLE_1 · TABLE_2
02 / Why it matters

A 0.4% math error
is a rejected lot.

HMA has to hit at least 95% LTMD. Below that, the engineer deducts pay or refuses the lot. One transposed count, one bad average, and a sublot that passed in the field fails on paper.

Caltrans Section 39 requires one density test per 1000 tons of HMA placed. Every test runs through TL-3112. Every RC% is argued over if it's close to the threshold.

This workbook removes the arithmetic from the argument. Hand it to a contractor's QC, hand it to the RE — the formulas are the formulas. You spend your time where judgment actually matters: the gauge seat, the lift thickness, the cold joint.

  • 01Minimum relative compaction (HMA)≥ 95.0%
  • 02Tests required per 1,000 tons placed1 min.
  • 03RC reported to nearest0.1 %
  • 04Density rounded to nearest0.01 g/cc
  • 05Correlation factor verified every3 mo.
  • 06Typical time saved per sublot~20 min
FREE · NO ACCOUNT

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XLS Bunker_CT-375_TL-3112.xlsx
v1.0 · 186 KB · Excel / Numbers / Sheets

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