UNIVERSITY OF GUYANA
DEPT. OF CIVL ENGINEERING
CIVL ENGINEERING DESIGNS
(CIV 2108)
DESIGN PROJECT 4 – RIGID PAVEMENT DESIGN
You are to perform checks for various pavement designs.
The details are as follows:
An eight-lane rigid pavement highway is to be constructed for moderate truck traffic. The
pavement is expected to last for 25 years, i.e., its design life is 25 years. Traffic volume data on
the highway indicate that the AADT (both directions) during the first year of operation is 27,700.
This volume is expected to undergo a 4% growth annually. However, the traffic composition now
will remain constant throughout the design life. At present, cars make up 50% of the traffic while
2-axle single-unit trucks account for 35%. There are also 3-axle single-unit trucks. Also, this
composition is maintained for every lane. The 2-axle and 3-axle trucks have axle weights of
10,000 lbs/axle and 15,000 lbs/axle, respectively.
The pavement will have the following characteristics:
•
contains doweled joints,
•
has a 6-inch cement-treated subbase,
•
has a subgrade k value of 155 lbs/in 3 ,
•
is without concrete shoulders
A test using the third-point method shows a concrete beam breaking under a pressure
measurement of 650 lb/in 2. Modulus of rapture
1. Perform calculations to check if the following depths is safe for the design period:
a. 4 inches
b. 4.5 inches
c. 5 inches
d. 5.5 inches
e. 6 inches
f. 6.5 inches
g. 7 inches
2. Is/are any of the above thicknesses enough for the associated rigid pavement design? If
yes, which one(s) and which would be the preferred thickness? If no, perform additional
calculations to determine the suitable thickness.
NB:
1. Show all calculations for equivalent stress, stress ratio factor and erosion factor for each
layer.
2. Calculations for each fatigue analysis and erosion analysis of each layer is required.
3. Begin each layer analysis on a new page to make it easier for the marker to understand
and grade your work.
4. Assignment must be typed (no handwritten documents will be accepted).
Resources:
1. You should use all tables and charts provided in the lectures to assist with this project.
2. You can also utilize the following source by Garber and Hoel (2009):
http://www.civilittee-hu.com/uploads/1/Traffic/book4th.pdf
3. You may also make use of the table in the other attached document to present a summary
of your results. You may add rows to the table for your results.