In 1996, a rigid pavement on a northbound section of interstate highway was designed with a 12-inch PCC slab, an Ec of 6x10^6 lb/in^2, a concrete modulus of rupture of 800 lb/in^2, a load transfer coefficient of 3.0, an initial PSI of 4.5, and a terminal serviceability index of 2.5. The overall standard deviation was 0.45, the modulus of subgrade reaction was 190 lb/in^3, and a reliability of 95% was used along with a drainage coefficient of 1.0. The pavement was designed for a 10-year life, and traffic was assumed to be composed entirely of tractor semi-trailer trucks with one 16-kip single axle, one 20-kip single axle, and one 35-kip tandem axle (the effect of all other vehicles was ignored). The interstate has four northbound lanes and was conservatively designed. How many tractor semi-trailer trucks, per day, were assumed to be traveling in the northbound direction

In 1996, a rigid pavement on a northbound section of interstate highway was designed with a 12-inch PCC slab, an Ec of 6x10^6 lb/in^2, a concrete modulus of rupture of 800 lb/in^2, a load transfer coefficient of 3.0, an initial PSI of 4.5, and a terminal serviceability index of 2.5. The overall standard deviation was 0.45, the modulus of subgrade reaction was 190 lb/in^3, and a reliability of 95% was used along with a drainage coefficient of 1.0. The pavement was designed for a 10-year life, and traffic was assumed to be composed entirely of tractor semi-trailer trucks with one 16-kip single axle, one 20-kip single axle, and one 35-kip tandem axle (the effect of all other vehicles was ignored). The interstate has four northbound lanes and was conservatively designed. How many tractor semi-trailer trucks, per day, were assumed to be traveling in the northbound direction

Traffic and Highway Engineering

5th Edition

ISBN:9781305156241

Author:Garber, Nicholas J.

Publisher:Garber, Nicholas J.

Chapter20: Design Of Rigid Pavements

Section: Chapter Questions

Problem 22P

See similar textbooks

Similar questions

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.
A 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:
A rigid pavement on a new interstate (3 lanes each direction) has been conservatively designed with a 12- inch slab, an Ec of 5.5 x 106 lb/in2 , a concrete modulus of rupture of 700 lb/in2 , a load transfer coefficient of 3.0, an initial present serviceability index of 4.5, and a terminal serviceability index of 2.5. The overall standard deviation is 0.35, the subgrade CBR is 25, and the drainage coefficient is 0.9. The pavement was designed for 600 30-kip tandem axles per day and 1400 20-kip single axle loads per day. If the desired reliability was 90%, how long was this pavement designed to last? 42 37 18 46
An undowelled rigid pavement in a subdivision roadway has thickness equivalent to 300 mm. What should be the allowable tensile strength of concrete in MPa in order to support a wheel load equivalent to 9 kN?
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.
Find the safe static wheel load that a 360 mm thick rigid pavement could carry without any dowel across the joints if the allowable tensile stress of concrete is 1.5 MPa.
An undowelled rigid pavement in a subdivision roadway has thickness equivalent to 300mm. What should be the allowable tensile strength of concrete in MPa in order to support a wheel load equivalent to 9kN?
A 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 reaction k of 170 lb/in3. The ESAL used for the design period is 2.5 ? 106. Using the AASHTO design method, determine a suitable thickness of the concrete pavement (to the nearest 1⁄2 inch), provided that the working stress of the concrete to be used is 650 lb/in2 and the modulus of elasticity is 5 ? 106 lb/in2. Assume the initial service- ability is 4.75 and the terminal serviceability is 2.5. Assume the overall standard devi- ation, So, as 0.35, the load transfer coefficient J as 3.2, the drainage coefficient, Cd as 1.15, and R as 95%.
4.13) A rigid pavement is being designed with the same parameters as used in Problem 4.5. The modulus of subgrade reaction is 300 1b/in? and the slab thickness is determined to be 8.5 inches. The load transfer coefficient is 3.0, the drainage coefficient is 1.0, and the modulus of elasticity is 4 million Ib/in?. What is the design modulus of rupture? (Assume that any parameters not given in this problem are the same as those given in Problem 4.5.) 4.5 has been added for reference.
A 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 reaction k of 170 lb/in3. The ESAL used for the design period is 2.5 x 106. Using the AASHTO design method, determine a suitable thickness of the concrete pavement (to the nearest 1⁄2 inch), provided that the working stress of the concrete to be used is 650 lb/in2 (i.e. S’c) and the modulus of elasticity is 5 x 106 lb/in2. 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, ZR as -1.645 and R as 95%.
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
1. During the AASHO road test, ONLY flexible pavements were constructed and tested.a. Trueb. False2. The AASHO present serviceability rating (PSR) was considered an objective quantity used to establish the performance of highway pavement in terms of applied traffic.a. Trueb. False3. The AASHTO present serviceability index (PSI) correlates the PSR to actual pavement performance in terms of applied traffic, and select distresses.a. Trueb. False4. There is only one AASHTO PSI equation that applies to both flexible and rigid pavements.a. Trueb. False5. The AASHTO PSI scale ranges from:a. 0-5b. 0-10c. 0-100d. None of the above