Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 25
25
· Pavement failure (rehabilitation trigger)--the condition individual condition indicator areas are computed by taking
level at which a major rehabilitation is required. integrals of the specific performance equations that define the
· Treatment failure--the condition level at which a treat- do-nothing performance curves. The important benefit-related
ment is considered failed (i.e., the benefits of the preven- areas are those below condition indicator curves that decrease
tive maintenance treatment are no longer being realized). over time and above condition indicator curves that increase
over time. The final do-nothing condition area for a given
If agencies are unsure about how to select these benefit cut- condition indicator is determined by applying the following
off values, it is recommended that values be set to closely area boundary conditions:
reflect current maintenance and rehabilitation policies. For
example, if an agency typically applies only one preventive · Y-axis limits--in the y direction, the pertinent area is
maintenance treatment in the life of a pavement, then the bounded by the defined upper and lower benefit cutoff
benefit cutoff value should be equal to the pavement failure values.
level because a major rehabilitation will most likely be the · X-axis limits--in the x direction, the pertinent area is
next pavement-related activity. In contrast, if an agency typ- bounded by zero on the lower end and the age at which
ically applies a second preventive maintenance treatment the performance curve intersects the benefit cutoff value
after the first application reaches a known condition failure on the upper end.
level, the benefit cutoff value can be set equal to the treat-
ment failure level. The area calculation details differ slightly depending on
whether the performance equation is decreasing or increas-
Step 3: Computation of Areas Associated ing. Equations 2 and 3 are used to compute the do-nothing
with the Do-Nothing Case benefit-related areas associated with decreasing and increas-
ing equations, respectively. These equations are functions of
The third step in the benefit calculation process involves the actual do-nothing mathematical equation and the upper
determining the total do-nothing condition curve areas. The and lower benefit cutoff values. Figure 3 illustrates the total
DECREASING RELATIONSHIP
UBC = Upper benefit cutoff value
Condition Indicator
AREADN-TOT(-)
LBC = Lower benefit cutoff value
X0 X1 X2
Age, years
INCREASING RELATIONSHIP
UBC = Upper benefit cutoff value
Condition Indicator
AREADN-TOT(+)
LBC = Lower benefit cutoff value
X0 X1 X2
Age, years
Figure 3. Total areas associated with decreasing and increasing
condition indicators for do-nothing options.
