CONCRETE WAQTC FOP AASHTO T 309 (22)
TEMPERATURE OF FRESHLY MIXED PORTLAND CEMENT CONCRETE
FOP FOR AASHTO T 309
Scope
This procedure covers the determination of the temperature of freshly mixed Portland
Cement Concrete in accordance with AASHTO T 309-22.
Warning—Fresh Hydraulic cementitious mixtures are caustic and may cause chemical burns
to skin and tissue upon prolonged exposure.
Apparatus
Container: Made of non-absorptive material and large enough to cover the sensor with
concrete at least 75 mm (3 in.) in all directions; concrete cover must also be a least three
times the nominal maximum size of the coarse aggregate.
Thermometer: Capable of measuring the temperature of the concrete throughout the
temperature range likely to be encountered, at least –18 to 50°C (0 to 120°F), and
readable to ±0.5°C (±1°F) or smaller.
Note 1: Thermometer types suitable for use include ASTM E1 mercury thermometer or ASTM E2251 Low
Hazard Precision Liquid-in-glass thermometer; ASTM E2877 digital metal stem thermometer; or
thermocouple thermometer ASTM E230, Type T Special or IEC 60584 Type T, Class 1.
Standardization of Thermometer
Each thermometer shall be verified for accuracy annually and whenever there is a question of
accuracy. Standardization shall be performed by comparing readings on the thermometer
with another calibrated thermometer at two temperatures at least 15°C or 27°F apart.
Sample Locations and Times
The temperature of freshly mixed concrete may be measured in the transporting equipment,
in forms, or in sample containers, provided the sensor of the thermometer has at least 75 mm
(3 in.) of concrete cover in all direction around it.
Complete the temperature measurement of the freshly mixed concrete within 5 minutes of
obtaining the sample.
37_T309_short_22 Concrete 10-1 Pub. October 2024 (v. 2025)
WSDOT Materials Manual M 46-01.46 Page 1 of 4
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T 309
CONCRETE WAQTC FOP AASHTO T 309 (22)
Procedure
1. Dampen the sample container.
2. Obtain the sample in accordance with the FOP for WAQTC TM 2.
3. Place sensor of the thermometer in the freshly mixed concrete so that it has at least 75
mm (3 in.) of concrete cover in all directions around it.
4. Gently press the concrete in around the sensor of the thermometer at the surface of the
concrete so that air cannot reach the sensor.
5. Leave the sensor of the thermometer in the freshly mixed concrete for a minimum of two
minutes, or until the temperature reading stabilizes.
6. Complete the temperature measurement of the freshly mixed concrete within 5 minutes of
obtaining the sample.
7. Read and record the temperature to the nearest 0.5°C (1°F).
Report
Results on forms approved by the agency
Sample ID
Measured temperature of the freshly mixed concrete to the nearest 0.5°C (1°F)
37_T309_short_22 Concrete 10-2 Pub. October 2024 (v. 2025)
Page 2 of 4 WSDOT Materials Manual M 46-01.46
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T 309
CONCRETE WAQTC FOP AASHTO T 309 (09)
PERFORMANCE EXAM CHECKLIST
TEMPERATURE OF FRESHLY MIXED CONCRETE
FOP FOR AASHTO T 309
Participant Name ______________________________ Exam Date ______________
Record the symbols “P” for passing or “F” for failing on each step of the checklist.
Procedure Element Trial 1 Trial 2
1. Obtain sample of concrete large enough to provide a minimum of
75 mm (3 in.) of concrete cover around sensor in all directions? _____ _____
2. Place thermometer in sample with a minimum of 75 mm
(3 in.) cover around sensor? _____ _____
3. Gently press concrete around thermometer? _____ _____
4. Read temperature after a minimum of 2 minutes or when
temperature reading stabilizes? _____ _____
5. Complete temperature measurement within 5 minutes of
obtaining sample? _____ _____
6. Record temperature to nearest 0.5°C (1°F)? _____ _____
Comments: First attempt: Pass Fail Second attempt: Pass Fail
Examiner Signature _______________________________WAQTC #:_______________
This checklist is derived, in part, from copyrighted material printed in ACI CP-1, published by the
American Concrete Institute.
21_T309_pr_09 Concrete 4-7 Pub. October 2024 (v. 2025)
WSDOT Materials Manual M 46-01.46 Page 3 of 4
January 2025
T 309
CONCRETE WAQTC FOP AASHTO T 309 (09)
21_T309_pr_09 Concrete 4-8 Pub. October 2024 (v. 2025)
Page 4 of 4 WSDOT Materials Manual M 46-01.46
January 2025
