3.5 Sequence With Slump, Temperature, Air, Density, and Specimens

ACI Concrete Field Testing Technician Grade I Study Guide Exam

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1 Orientation: Certification Requirements, Written Exam, Performance Exam, and Study Sources

1.1 Credential Purpose and Official Definition 1.2 Eligibility and the Two-Part Certification Path 1.3 Written Exam Format and Dual Passing Rule 1.4 Performance Exam Format and Grading 1.5 Current Study Sources and CP-1 41st Edition 1.6 Validity, Recertification, and Myth Control

2 JTA, Performance Checklists, Common Fail Points, and Field Mindset

2.1 JTA as the Exam Blueprint 2.2 Written Knowledge Versus Performance Skill 2.3 Performance Checklists and the Six Demonstrations 2.4 Timing, Sequence, and Verbal Description Discipline 2.5 Common Fail Points and Result Recording 2.6 Field Mindset, Exam Habits, and Second Trials

3 ASTM C172: Sampling Fresh Concrete and Field Sample Control

3.1 Representative Sampling Purpose and Exam Role 3.2 Sampling Locations and Middle-Discharge Control 3.3 Composite Sample Timing, Remixing, and Protection 3.4 Sample Size, Large Aggregate, and Wet Sieving 3.5 Sequence With Slump, Temperature, Air, Density, and Specimens 3.6 Performance Exam Verbal Description and Field Habits

4 ASTM C1064 Temperature and ASTM C143 Slump

4.1 ASTM C1064 Purpose, Equipment, and Timing 4.2 Sensor Placement, Stabilization, and Reporting 4.3 Temperature Field Errors and Performance Habits 4.4 ASTM C143 Scope, Equipment, and Setup 4.5 Filling, Rodding, Lifting, and Measuring Slump 4.6 Invalid Slump Results, Reporting, and Integrated Habits

5 ASTM C138: Density, Unit Weight, Yield, and Gravimetric Air

5.1 Purpose, Equipment, and the Calibrated Measure 5.2 Sampling, Filling, and Consolidation Choice 5.3 Strike-Off, Cleaning, Mass, and Density 5.4 Yield, Relative Yield, and Batch Comparison 5.5 Gravimetric Air and Theoretical Density 5.6 Reporting, Validity, and Calculation Traps

6 ASTM C231: Pressure Air Method, Type B Meter, and Aggregate Correction

6.1 Scope, Principle, and When Pressure Air Fits 6.2 Type B Meter Equipment, Calibration, and Setup 6.3 Sampling, Bowl Filling, Consolidation, and Strike-Off 6.4 Type B Sequence: Water, Petcocks, Pressure, and Reading 6.5 Aggregate Correction Factor and Final Air Content 6.6 Reporting, Validity, and Invalid-Result Traps

7 ASTM C173: Volumetric Air Method, Rollameter, Alcohol Correction, and Validity

7.1 Scope, Equipment, and When the Volumetric Method Fits 7.2 Sample, Bowl Filling, Consolidation, and Strike-Off 7.3 Water, Alcohol, Initial Liquid Level, and Sealing 7.4 Inversion, Shaking, Rolling, and Air Release 7.5 Reading Agreement, Out-of-Range Steps, and Invalid Results 7.6 Alcohol Correction, Calculation, Reporting, and Performance Habits

8 ASTM C31: Making and Curing Cylinders and Beams, Initial Curing, and Transport

8.1 Purpose, Sample, Equipment, and Specimen Plan 8.2 Cylinder Molding, Consolidation, Finishing, and Identification 8.3 Beam Molding, Flexural Specimens, and Finishing 8.4 Initial Curing, Protection, Temperature, and Moisture 8.5 Standard Curing, Field Curing, Final Curing, and Interpretation 8.6 Transport, Lab Handoff, Reporting, and Common Failures

9 Integrated Field Workflow: Test Order, Documentation, and Quality Control

9.1 Field Sample to Report Workflow 9.2 Test Order and Parallel Timing 9.3 Documentation and Report Accuracy 9.4 Invalid Results and Retest Decisions 9.5 QA/QC Communication and Acceptance Context 9.6 Contamination, Delays, and Handoff Control

10 Written Exam Strategy: Numerical Values, Calculations, and Category Scoring

10.1 One-Hour Written Exam Pacing 10.2 Category Scoring and the No-Compensation Rule 10.3 High-Yield Numerical Values and Units 10.4 Density, Yield, and Gravimetric Air Calculations 10.5 Air Content Corrections and Validity Checks 10.6 Method-by-Method Practice Plan

11 Performance Exam Strategy: Equipment Setup, Examiner Communication, and Remediation

11.1 Performance Exam Map and Mindset 11.2 Equipment Setup, Station Control, and Safety 11.3 Examiner Communication and Speaking the Work 11.4 One-Step Errors, Timing, and Method Control 11.5 C172 Verbal Description Under Pressure 11.6 Remediation, Retest Planning, and Field Confidence

12 Final Review: Recertification, Career Paths, and Next ACI Credentials

12.1 Two-to-Six Week Final Review Plan 12.2 Final Week and Test-Day Checklist 12.3 CP-1, JTA, and Source Control 12.4 Recertification, Five-Year Cycle, and Re-Exam Requirement 12.5 Career Paths After Field Testing Grade I 12.6 Next ACI Credentials and Growth Map

3.5 Sequence With Slump, Temperature, Air, Density, and Specimens

Key Takeaways Explain This Topic AI

C172 feeds C1064/C1064M, C143/C143M, C138/C138M, C231/C231M, C173/C173M, and C31/C31M, all of which depend on the same sample.

Slump, temperature, and air-content tests start within 5 minutes of the final portion; cylinder molding starts within 15 minutes of fabricating the composite.

Equipment should be staged before sampling so a slow setup never consumes the 5-minute or 15-minute window.

The technician records the source, batch or truck ID, sampling time, and any unusual treatment so the sample-to-report chain is traceable.

Last updated: June 2026

Turning One Sample Into a Test Workflow

A C172 composite is usually collected because several tests must run from the same concrete. Temperature (C1064/C1064M) may be measured in the sample or the concrete as delivered. Slump (C143/C143M) uses a portion of the composite. Air content uses another portion in either the pressure meter (C231/C231M) or the volumetric meter (C173/C173M). Density and yield (C138/C138M) use a calibrated measure. Strength specimens (C31/C31M) are molded from the representative concrete after the fresh-property tests are underway.

The main risk is not that the technician forgets a procedure. It is that the technician treats the sample as if each method has unlimited time. C172 requires slump, temperature, and air-content testing to start within 5 minutes of obtaining the final portion, and cylinder or beam molding to begin within 15 minutes of fabricating the composite. If the technician pauses to wash tools, look for a thermometer, assemble an air meter, or label molds, the sample ages before testing.

A Stable Order of Operations

The exact sequence flexes with jobsite logistics, but the control habits are constant. Stage equipment first. Collect the sample correctly. Remix it to uniformity. Protect it. Start the time-sensitive fresh tests. Keep enough concrete for density and strength specimens. Record results immediately and clearly. If a test is invalid, repeat it on another portion of the same sample only when the standard allows and the sample is still within its time and protection controls.

Downstream test C172 connection Field habit
Temperature (C1064) Within the 5-min start window Insert the sensor promptly, keep it embedded
Slump (C143) Uses representative composite concrete Start quickly and finish without interruption
Air content (C231/C173) Sensitive to handling and delay Keep the sample uniform before filling the meter
Density/yield (C138) Needs a representative, consolidated volume Avoid losing coarse aggregate
Strength specimens (C31) Mold within 15 min of fabricating composite Have molds staged before sampling
Documentation as Part of the Sequence

A strong performance habit is to narrate while working . Even during a slump or air demonstration, speaking the sample-control logic shows the test is tied to C172. A candidate can state that the sample has been remixed to uniformity and protected, then move directly into the method being demonstrated.

Documentation closes the sequence. Record the sample source, the truck or batch identifier, the time of sampling, the test times when project practice requires them, and any unusual condition such as wet sieving, delayed discharge, or visible segregation. Field results are used by others, so the technician must keep the chain from sample to report clear and traceable.

Sequence memory aid:

Ready the equipment before collecting concrete.

Collect representative portions and fabricate the composite.

Remix and protect the sample immediately.

Start temperature, slump, and air tests within 5 minutes of the final portion.

Mold strength specimens within 15 minutes of fabricating the composite, and document the sample history.

A Realistic Field Walkthrough

Consider a typical truck delivery for an acceptance set of slump, temperature, air, density, and three cylinders. Before the truck arrives, the technician dampens the slump cone, checks the thermometer, assembles and cleans the air meter, calibrates or confirms the density measure, and stages three molds. When discharge reaches the middle of the batch , the technician collects two or more portions into a clean damp wheelbarrow, finishing all portions within the 15-minute collection window.

The portions are remixed with a shovel to uniformity and shielded from sun and wind. The 5-minute clock now governs: the technician embeds the thermometer for temperature, runs the slump test, and fills the air meter, all started within those five minutes. Density is taken from the same protected sample. Finally, cylinders are molded so that filling the first mold begins within 15 minutes of fabricating the composite. Every result is recorded with the truck ID and sampling time.

Step Governing limit What the technician is protecting
Stage equipment Before sampling The time windows themselves
Collect portions 15-min collection A single-age composite
Remix and protect Continuous Uniformity and fresh properties
Temperature, slump, air 5-min start As-delivered fresh properties
Mold cylinders 15-min from composite Representative strength specimens
When a Test Must Be Repeated

Sometimes a fresh test is invalid: an air test is botched, a slump collapses because of an off-center lift, or equipment fails mid-test. The technician may repeat the test on a fresh portion of the same composite only if the sample is still uniform, protected, and within the relevant time controls. If the sample has aged past its windows or lost representation, a repeat reading is no better than the first. In that case the correct action is to obtain a new sample, which means the technician must again coordinate with the crew and the truck.

This is why margin matters. A technician who collected only the minimum, skipped protection, or let the clock run has no room to recover from a normal mishap. Good sample control is what makes an orderly repeat possible instead of a scramble. Throughout, documentation of the source, timing, and any unusual handling keeps the entire set defensible if results are ever questioned.