Research Home  Pavements Home  
This report is an archived publication and may contain dated technical, contact, and link information 

Publication Number: FHWARD98155 Date: FEBRUARY 1999 
Introduction 
After the agency has defined the specification and developed the corresponding projectspecific preconstruction output, the agency may then use the developed specification for acceptance. PRSrelated contractor pay adjustments are then determined based on the actual samples taken from the asconstructed pavement lot (in accordance with the agencydefined AQC acceptance sampling and testing plan). This chapter describes the procedures to be used by an agency to determine Level 1 or Level 2 pay adjustments for a given asconstructed pavement lot.
Step 1: Dividing the AsConstructed Pavement Lot into Sublots 
To judge the quality of the asconstructed inplace pavement lot, the agency must conduct sampling and testing in accordance with the previously chosen acceptance sampling and testing plan. (Note: The defined acceptance sampling and testing plan is determined in accordance with the guidelines presented in the section titled Selecting an AQC Acceptance Sampling and Testing Plan, in chapter 5 of this volume.) As a first step in the sampling of the pavement, the pavement lot is divided into sublots. Prior to the placement of any paving for the given lot, the agency must estimate the starting and ending stations of all of the sublots expected to be paved within that lot. These specific stations are determined by assuming sublot lengths equal to the chosen target sublot length (the target sublot length is determined in accordance with the guidelines presented in the section titled Selecting an Appropriate Target Sublot Length, in chapter 5 of this volume). An appropriate number of expected sublots are defined so that sublots are defined well past the expected lot length (see the section titled Definition of Lots and Sublots in chapter 5 of this volume).
Step 2: Determining the AsConstructed Acceptance Sampling Locations 
The estimated sublot starting and ending stations allow the agency to determine random sampling locations prior to the placement of any pavement within the lot. For each AQC, the appropriate number of random sampling locations per sublot is identified by the agency in accordance with the guidelines presented in the section titled Recommended Number of AQC Samples Per Sublot, in chapter 5 of this volume. (Note: The chosen AQC sample types determine what sampling locations are required.) Specific sample locations are, therefore, determined based on the agencychosen sample specimen types and in accordance with the guidelines presented in the section titled Selection of Random Sampling Locations, in chapter 5 of this volume.
Step 3: Conducting Lot Acceptance Sampling and Testing 
Once the paving begins for a given lot, the actual sublot lengths are determined in accordance with the guidelines presented in the section titled Determining Actual Sublot Lengths in the Field, in chapter 5 of this volume. The appropriate sample specimens are taken at the random sample locations identified in the previous step. If replicate samples are taken at a given sampling location (e.g., three cylinders molded from a batch of concrete taken from one randomly selected longitudinal sample location), the replicate sample specimen testing values are averaged to give one AQC testing value representing the sample location. These sample location representative testing values are used to define the quality of the pavement lot.
Step 4: Determining the Overall Lot Pay Factor 
The procedures used to determine an overall lot pay factor differ for Level 1 and Level 2 specifications. The Level 1 overall lot pay factor is computed using a chosen composite pay factor equation, while the Level 2 pay factor is based on a direct comparison of the simulated asdesigned LCC mean and the estimated asconstructed LCC. The details of both of these procedures are described separately below.
Level 1—Determining the Overall Level 1 Lot CPF
If the Level 1 procedure is used to calculate the pay
adjustment, the following steps apply:
Summarizing the AsConstructed AQC Acceptance Data for the Lot
The first step in calculating a Level 1 lot pay adjustment
requires that the measured asconstructed AQC acceptance data be summarized for the entire
lot. Therefore, all of the representative testing values (representing every
sample location within the lot—all sublots are included) are summarized into one lot
mean and unbiased standard deviation for each AQC. These AQC lot means and unbiased
standard deviations are then used in the developed individual AQC pay factor curves and
equations.
Computing the Individual Pay Factors for Each AQC
Individual pay factors are determined independently for each
AQC based on the respective lot means and unbiased standard deviations computed in the
previous section. For each AQC, the representative lot mean and unbiased standard
deviation is used in the following stepbystep procedure to determine individual AQC
Level 1 pay factors:
where
AQCPF_{LOT} = Representative individual AQC pay factor, percent.Finally, this procedure is repeated so that representative individual AQC pay factors
are determined for each AQC included in the specification.
Computing the Level 1 Lot CPF
For Level 1, the overall lot CPF is calculated using the
specific CPF equation determined by the agency in accordance with the guidelines presented
in the section titled Defining a
Level 1 Composite Pay Factor Equation, in chapter 6. Just as with the
individual AQC pay factors, the agency has the option to apply pay factor limits to the
computed lot CPF. The limited CPF, therefore, is the representative CPF used to
compute the overall lot pay adjustment. Any such lot CPF pay factor limits shall be
selected in accordance with the guidelines presented in the section titled Selecting Pay Factor Limits,
in chapter 6.
Level 2—Determining the Overall Level 2 Lot Pay Factor
If the Level 2 procedure is used to calculate the pay
adjustment, the following steps apply:
Summarizing the AsConstructed AQC Acceptance Data for Each Sublot
The first step in calculating the Level 2 lot pay adjustment
requires that the measured asconstructed AQC representative testing values be summarized
for each sublot independently. The means of these AQC testing values are computed
for each sublot and are then used to define the asconstructed quality of the pavement lot
in the PaveSpec 2.0 software. The future performance and corresponding lot
LCC's (over the agencychosen analysis period) related to the computed AQC sublot
means are determined using the PaveSpec 2.0 software. The total PW value of the
predicted lot LCC's (LCC_{CON}) is used as the overall measure
of quality for the asconstructed lot. The overall Level 2 lot pay factor is then
computed as a function of this LCC_{CON}, the simulated asdesigned
LCC (LCC_{DES}), and the actual contractor bid price (BID_{CONTRACTOR})
using equation 3 in chapter 3.
As with the Level 1 CPF, the agency has the option to apply
pay factor limits to the computed overall Level 2 lot pay factor. The limited lot
pay factor, therefore, is the representative pay factor used to compute the overall lot
pay adjustment. Any such lot pay factor limits shall be selected in accordance with
the guidelines presented in the section titled
Selecting Pay Factor Limits,
in chapter 6.
Step 5: Computing the Lot Pay Adjustment 
The total payment to the contractor for the asconstructed lot may be determined using equation 23.
Contractor Lot Payment = BID_{CONTRACTOR} * (PF_{LOT} / 100) * LOT_{LENGTH} (23)where
Contractor Lot Payment = Adjusted payment paid to the contractor for the asconstructed lot, $.LOT_{LENGTH} = Measured actual asconstructed lot length, km.
Topics: research, infrastructure, pavements and materials Keywords: research, infrastructure, pavements and materials TRT Terms: research, facilities, transportation, highway facilities, roads, parts of roads, pavements Updated: 04/07/2011
