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Advertising supplement provided by Portland Cement Association

by Jennifer Grover Prokopy

Evaluation and Corrective Action

Following the “closed loop” QC process, each inspection and test report should be evaluated, and appropriate (sometimes corrective) action should be taken. Even when results indicate that no corrective action is needed, the reports should be filed according to records retention policies outlined in the QA program.

Corrective action will not always mean a change in materials or procedures; it may at times mean the original criteria is incorrect, and the standards of measurement or the testing procedures must be changed. Working with the building team from the outset of a project, and keeping lines of communication open in all directions, will help reduce situations where major changes are needed.

ASTM Specifications:

Their Role in a QA Program and in Quality Control Procedures

Clearly, testing is an important part of quality assurance, and of quality control measures performed on-site during construction. Some common misconceptions about field testing include designating an incorrect test to be performed, or improperly executing a correctly specified test. Properly conducted field testing must be preceded by the correct specifications and preparations, and care should be taken to perform the most appropriate test.

ASTM C270: Standard Specification for Mortar for Unit Masonry

Architects and other specifiers must be familiar with ASTM C270, Standard Specification for Mortar for Unit Masonry, the standard that governs masonry mortars. The specification addresses mortars for reinforced and non-reinforced unit masonry structures, and covers the four mortar types: M, S, N and O.

(For more information on choosing a mortar type, see Table 2 on page 198.)

The specification sets out acceptance criteria for mortars, whether they are mixed using masonry cement, mortar cement, or a portland cement-lime combination.

The standard also addresses two methods of specifying mortars, proportion or property specification requirements. Specifiers must choose one or the other method, never both. If neither is chosen, the proportion specifications apply.

If proportion specification requirements are used, no mortar tests are required. The mortar must consist of a mixture of materials meeting proportion specifications outlined in ASTM C270 (see Table 1 on page 198).

If property specifications are used, mortar compressive strength testing (as well as testing of other properties) will be performed to determine whether the laboratory-prepared mortar meets the compressive strength as outlined in ASTM C270. The mortar is mixed and tested under laboratory conditions with specific mixing procedures, dry sand, exact water proportions, and ideal curing conditions to determine whether the “recipe” that will be used for the field mortar has all the required properties (see Additional Required Reading).