11. Quality Assurance

11.8 Acceptance

Acceptance is the process whereby all factors used by the agency (i.e., sampling, testing, and inspection) are evaluated to determine the degree of compliance with contract requirements and to determine the corresponding value for a given product. QC measurements may or may not be used in the acceptance decision process, depending on the way the specification is written. If the contractor’s QC measurements are used, the contractor is typically required to perform specific tests at stated frequencies.

The agency may also rely on supplier/vendor testing or certification for the acceptance of some items. All persons directly participating in acceptance activities must be qualified for their assigned responsibilities and are usually certified by the State DOT or airfield groups. Only qualified laboratories should perform the required tests.

QA specifications usually contain an acceptance plan that identifies a method of taking measurements for the purpose of determining the acceptability of a lot of asphalt mixture production and construction. The acceptance plan usually contains the following:

Test method and point of sampling.
Lot size.
Sample size.
Quality measure.
Acceptance limits.
Risk evaluation.
Pay adjustment provisions (outlines pay deductions/bonuses).

11.8.1 Material Acceptance

There are often several components to how project work is accepted. Some work is not tested by QC or a representative of the owner. Certain products, such as lighting to be used on airfield runways, are accepted based on some type of manufacturer certification. Other products, like asphalt mixtures, are sampled and tested for acceptance. Specified tests may include some or all of the following:

Asphalt content.
Gradation (usually specific sieve sizes).
Volumetrics (air voids, VMA, VFA).
Performance tests (for rutting, cracking potential).
Mat density tests (cores, nuclear density gauge, non-nuclear density gauge).
Smoothness.

Specified testing (and thereby testing costs) should be relative to the project size and/or importance. Smaller projects may specify very few tests at infrequent intervals to help ensure the owner is receiving a quality product without spending too much relative to the project cost. Larger projects, or even smaller projects assigned a high level of importance for various reasons, will typically require a greater number of tests at more frequent intervals.

11.8.2 Responses to Failing Test Results

Contract language often falls short when the consequences of work not meeting contract requirements are not detailed. The responses could vary widely, depending on what work is out of specification and by how much. Potential responses, ranging from least to most expensive, could include the following:

11.8.2.1 Do Nothing

An owner may elect to do nothing in response to out-of-specification work if the anticipated functionality would have no long-term detrimental effect. For example, if the binder content is too low on a temporary crossover. If the crossover functions by safely moving traffic from one area to another for the planned duration and is then removed, there is no reason to apply any type of penalty for a low binder content. It is not necessarily reasonable to apply requirements for asphalt mixtures intended to last 20 years to asphalt mixtures intended to last 6 months.

11.8.2.2 Leave in Place but Require an Extended Warranty

This option may be viable when the anticipated effects of out-of-specification material reveal themselves in a relatively short time, perhaps within a few months or years. An example of this is a mixture meeting rut testing requirements during mix design but failing rut testing requirements during required QC or acceptance testing during production. Most rutting that occurs on a mat will happen during the first summer of service. Any additional rutting will likely take place during the second summer of service. Therefore, a 2-year warranty outlining maximum rut allowances and required contractor responses to repair the issue would likely serve the interests of the owner. Because cracking typically occurs later in the mat service life, this may not be a good option for failed cracking tests.

11.8.2.3 Grind Rough Areas So They Meet Smoothness Requirements

Rather than applying a penalty, contractors are sometimes allowed to diamond-grind rough areas that cause failures in the smoothness specifications. For example, for airfields, P-401 says that areas with humps or depressions that exceed grade or smoothness criteria and that retain water on the surface must be ground off, provided the course thickness after grinding is not more than 1/2 inch (12 mm) less than the thickness specified on the plans. Of course, the grinding work must be done with appropriate equipment and enough blades to keep the process from causing raveling, aggregate fractures, spalls, or other pavement distress. It must also provide smooth transitions to areas that did not require grinding.

11.8.2.4 Deduct Pay

A more severe penalty for results not meeting specifications is a pay deduction. In statistically based specifications, the MOQ is any of several mathematical tools that are used to quantify the level of quality of an individual quality characteristic. These tools, such as AAD and PWL (discussed in sections 11.2.3.1 and 11.2.3.2), allow an assessment of test data showing defective results. The pay adjustment provision in the contract penalizes the contractor a percentage of the bid cost. The further out of specification, the higher the penalty. The worst-case pay deduction is to leave the material in place but assess a 100-percent pay deduction.

11.8.2.5 Place Surface Seal or Thin Overlay

This option does not penalize the contractor by lowering the percent paid on a particular bid item. Rather, it requires the contractor to do some type of extra work at no expense to the owner. This option might be pursued if the surface of the mat had some type of defect that was not structural. Perhaps the surface might appear to have an open texture, and field permeability testing showed high permeability where it was not desired. Surface sealing would lower the permeability of the mat. Another example might be that the contractor did not use a specified skid- or polish-resistant aggregate in the surface mix. A thin overlay would provide a new wearing surface. The contractor might place one of these surface types at no cost if the penalty for not doing so exceeded the cost of the new surface.

11.8.2.6 Remove and Replace

This option is the harshest penalty that owners could assess. If the work quality is so poor that the owner would incur high costs to rehabilitate or maintain it, the order would be given to remove the work and replace it—all at the contractor’s expense. Not only is there a 100-percent penalty for the first attempt at the work, but there is also the additional cost of doing it all again.

It would be best if the situations leading to these punitive actions were clearly described in the contract documents. Both the owner and the contractor would clearly understand the ramifications of any substandard work. If the situations were not agreed to in the contract, legal action is often pursued, which could be costly to both parties.

It should also be noted that the opposite is true: many specifications provide incentives to the contractor for measured quality above a prescribed threshold. These incentives most often come in the form of some type of bonus pay but can also come in the form of relaxed requirements in related areas of the specifications.

11.8.3 Project Acceptance

The focus of QC is material acceptance. However, when the project work is essentially complete, a final inspection takes place regarding final project acceptance. The completion of major tasks is verified and a punch list of relatively minor tasks to be completed is generated before the project is accepted.

A final estimate is generally produced to reflect items remaining to be resolved, such as the following:

Agreement of price reductions assessed for work or materials not meeting contract specifications.
Incentives to be paid for qualifying work or materials.
Liquidated damages assessed for failure to complete project work within a specified timeframe.
Payroll records, if required.
Copies of any manufacturer’s warranties for materials, equipment, and installations.
Verification of final cleanup.
Complete release of all claims for labor and materials.
Statements signed by subcontractors indicating payment was received.
Sales tax completion forms.
All required as-built or as-constructed drawings.
Any other adjustments as required by the contract.

Project acceptance is simply the process of making sure the project activities and paperwork are complete—that every detail is meticulously addressed so that no further payment or correspondence is required between owner and contractor.