Traffic and Highway Engineering
5th Edition
ISBN: 9781305156241
Author: Garber, Nicholas J.
Publisher: Cengage Learning
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Chapter 20, Problem 17P
To determine
The slab thickness according to AASHTO Alternate Design method of a rigid pavement.
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Question 3: A rigid pavement is designed with an 11-inch slab thickness, 95%
reliability, E, 4,000,000 lb/in', modulus of rupture of 650 lb/in', modulus of
subgrade reaction of 200 lb/in', a 3.2 load transfer coefficient, initial PSI of 4.7,
final PSI of 2.5 (A PSI = 2.2), overall standard deviation of 0.40, and a drainage
coefficient of 1.0. The pavement has 20 years design life. The pavement has three
lanes, with PDL = 0.6 for trucks that have three axles: one 25,000 single axle, one
32,000 lb tandem axle and one 50,000 lb triple axle. What is the daily estimated
truck traffic on the three lanes? Solve using AASHTO design Nomographs.
A rigid pavement is designed with a 11-inch slab, an E_c of 6 million Ib/in^2, a concrete modulus of rupture of 432 Ib/in^2, a
load transfer coefficient of 3.0, an initial PSI of 4.50, and a TSI of 2.5. The overall standard deviation is 0.56, the modulus of
subgrade reaction is 190 Ib/in^3, and a reliability of 90% is used along with a drainage coefficient of 0.87. The pavement is
designed assuming that traffic is composed entirely of trucks (50 per day). Each truck has one 20-kip single axle and one
42-kip tandem axle (the effect of all other vehicles is ignored). A section of this road is to be replaced (due to different
subgrade characteristics) with a flexible pavement having a SN of 5 and is expected to last the same number of years as
the rigid pavement. What is the assumed soil resilient modulus? (Assume that all other factors are the same as for the rigid
pavement). Please report your answer as a decimal in units of Ib/in^2. For example, report 3000.6 Ib/in^2 as 3000.6.
Q: Evaluate whether 9in of slab thickness for rigid pavement will be
adequate on a rural expressway for 20-year analysis period if design
criteria are as follows:
Pi = 4.5
Pt =2.5
ESAL over design period = 6* 10
Concrete Elastic modulus, Ee = 5*106 Ib/in?
%3D
Mean Concrete modulus of Rupture 700 Ib/in?
Drainage Coefficient Ca = 1.0
R = 0.95
So = 0.3
K = 170 Ib/in
%3D
Load transfer coefficient = 3.2
Chapter 20 Solutions
Traffic and Highway Engineering
Ch. 20 - Portland cement concrete consists of what four...Ch. 20 - List and briefly describe the five main types of...Ch. 20 - What is the main requirement for the water used in...Ch. 20 - Prob. 4PCh. 20 - Prob. 5PCh. 20 - Prob. 6PCh. 20 - Prob. 7PCh. 20 - Prob. 8PCh. 20 - Prob. 9PCh. 20 - Prob. 10P
Ch. 20 - Prob. 11PCh. 20 - Prob. 12PCh. 20 - Repeat Problem 20-12, with the slab containing...Ch. 20 - Prob. 14PCh. 20 - Prob. 15PCh. 20 - Prob. 16PCh. 20 - Prob. 17PCh. 20 - Prob. 18PCh. 20 - An existing rural 4-lane highway is to be replaced...Ch. 20 - Prob. 20PCh. 20 - Prob. 21PCh. 20 - Prob. 22PCh. 20 - Prob. 23PCh. 20 - Prob. 24PCh. 20 - Prob. 25PCh. 20 - Prob. 26PCh. 20 - Prob. 27P
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- Q6: Designing a Rigid Pavement Using the AASHTO Method (Find D) Effective modulus of subgrade reaction, k = 480 lb/in³ Mean concrete modulus of rupture, Sc = 725 lb/in² Load transfer coefficient, J = 3.9 Ec = 4500000 Drainage coefficient, Ca = 1.0 Design serviceability loss, APSI = 1.5 ZR (Standard normal deviation) = -1.282 Overall standard deviation, So = 0.4 Cumulative 18 kip ESAL = (37900000)arrow_forwardB. A rigid pavement with a 10-inch slab thickness, 90 percent reliability, E. = 4 million lb/in², 600 lb/in² modulus of rupture, 150 lb/in³ modulus of subgrade reaction, a 2.8 load transfer coefficient, initial PSI of 4.8, final PSI of 2.5, overall standard deviation of 0.35, and a drainage coefficient of 0.8 is designed. The pavement's design life is 20 years. The three-lane road is built for vehicles with one 20,000-pound single axle, one 26,000-pound tandem axle, and one 34,000-pound triple axle. Calculate the projected daily truck traffic on the three lanes.arrow_forwardA six-lane concrete roadway is being designed for a metropolitan area. This roadway will be constructed on a subgrade with an effective modulus of subgrade reactionk of 170 Ib/in^3. The ESAL used for the design period is 6.9* 10^6. Using the AASHTO design method, determine a suitable thickness of the concrete pavement (to the nearest 12 inch). provided that the working stress of the concrete to be used is 650 lb/in2 and the modulus of elasticity is 5 *10^6 Ib/in^2. Assume the initial serviceability is 4.75 and the terminal serviceability is 2,5. Assume the overall standard deviation, So, as 0.35, the load transfer coefficient J as 3.2. the drainage coefficient. Cd as 1.15. and R as 95%. Answer:arrow_forward
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