Testing Standards and Quality Assurance — Worked Examples

A concrete report identifies two cylinders as C-104A and C-104B but does not identify the truck, placement location, sample time, or batch represented. Determine why the report is incomplete for acceptance use.

Five replicate test results are 30.1, 29.8, 30.4, 30.0, and 29.9 MPa. Calculate the mean, sample standard deviation, and coefficient of variation.

A certified reference value is $500.0\text{ MPa}$. A laboratory reports 480.1, 480.5, 479.8, 480.2, and 480.0 MPa. Interpret precision and bias qualitatively.

A compression machine received formal calibration six months ago. Before today's test, a required verification check falls outside the permitted tolerance. The annual calibration due date has not passed. Decide whether testing should continue.

A calculation produces $30.123456\text{ MPa}$, but the governing test method requires reporting strength to the nearest $0.1\text{ MPa}$. Determine the reportable value.

A material result falls below the project limit. The technician proposes deleting it because a second test on another specimen passes. Determine the correct quality process.

A report shows one low concrete strength value. Determine the review sequence before concluding that the structural concrete is deficient.

A contractor cites a remembered “Blue Book item number” from an older project as proof that a material and test frequency are acceptable on a new DPWH contract. Determine the document-control response.