chapter 3 rigid pavement - DOT On-Line Publications - Department ...

November when there were reported temperature variations as high as
40 degrees.
The pavement opened to traffic in late 1975. Pavement failures in the
widened (right) lane of the eastbound roadway were noted in February 1976.
The number of failures increased substantially during March and April. The
State acted quickly in formulating a plan for investigating the causes of
the failures.
In June 1976, a report was issued that included data from an extensive
field study. However, the study only examined project data related to the
widened lane and does not discuss cracks, subbase, soils, concrete quality,
etc. of the overlay section of the project since, at that time, there was
little distress in the overlay section.' Briefly, the report concluded the
failures were design associated and included the following: a) inadequate
pavement support and the inability of the granular base to drain water away
from under the pavement could have resulted in lower stability, b) adverse
climatic conditions had reduced the concrete maturity at an early age and
resulted in formation of closely spaced transverse cracks, c) the nature of
the chairs and poor workability of the concrete could have contributed to
the voids and weaknesses in the concrete cross section. .
A second report was prepared in June 1982 and attempted to expand on what
was learned from the 1976 study. At the time, the westbound lanes of
Route XX had performed satisfactorily whereas the eastbound lanes had
exhibited distress. The study concluded: a) pavement failures were
primarily in these outside (widened) lanes, b) percent of steel
reinforcement met the specifications, c) the pavement thicknesses were
within the specification tolerance, d) numerous voids were reported in the
lower half of the slabs but have not contributed significantly to the
failures, e) the CRC overlays were performing satisfactorily and no visibie
signs of distress were noted, f) a significant portion of the CR-6 subbase
material had a high content of fines that led to poor drainage
characteristics, g) percent of air entrainment for eastbound and westbound
lanes was within specification limits, h) unfavorable curing temperatures
were present for the eastbound lanes, i) the crack spacing for the
eastbound lanes was in the range of 2 feet apart while the range in the
westbound lanes was generally 4-16 feet, and j) the eastbound shoulder lane
exhibited high deflection characteristics.
By 1986, it was noted that a large number of areas of pavement distresses
were beginning to occur in the middle lane and a lesser number were showing
up in the high speed lane. The FHWA Division Office on (date), sent to.the
State a special report on the Route XX pavement distress and requested a
detailed investigation of the pavement to determine the most cost-effective
type of repair to !‘* undertaken and determine what lessons could be learned
and applied toward IIther proposed CRCP projects.
3.7.5