Q.2- Design a flexible pavement by AASHTO method and draw typical cross section of the flexiblePavement for rural highway has following data: -Elastic modulus of Asphalt is 450000 Ib/in², Mr. of base-31000 psi, Mr. of subbase=13500 psi,CBR of base-100 CBR of subbase=22 subbase of subgrade =6 water removed with one weekPercentage of time pavement structure is exposed to moisture levels-30% reliability=95%Standard deviation=0.45 initial serviceability=4.2 terminal serviceability=2.5 and ESAL=2*106subgrade =1500 CBRMrكلية .المنصورالجامعة

Answered: Q.2- Design a flexible pavement by…

Traffic and Highway Engineering

5th Edition

ISBN:9781305156241

Author:Garber, Nicholas J.

Publisher:Garber, Nicholas J.

Chapter19: Design Of Flexible Highway Pavements

Section: Chapter Questions

Problem 16P

See similar textbooks

Similar questions

Repeat Problem 19-7 using two different depths of untreated aggregate bases of 6 in. and 12 in. Highway contractors in your area can furnish rates for providing and properly laying an asphalt concrete surface and untreated granular base. Assume a structural coefficient of 0.12 for the base course. If these rates are available, determine the cost for constructing the different pavement designs if the highway section is 5 miles long and the lane width is 12 ft. Which design will you select for construction?
Given the specifications for an asphaltic concrete mixture and the results of a sieve analysis, determine the proportion of different aggregates to obtain the required gradation. Coarse aggregates: 60% Fine aggregates: 35% Filler: 5%
Given four different types of aggregates to be used to produce a blended aggregate for use in the manufacture of asphaltic concrete, determine the bulk specific gravity of the aggregate mix.
Three groups of students from the Geotechnical Engineering class collected soil-aggregate samples for laboratory testing from a recycled aggregate processing plant in Palm Beach County, Florida. Three samples, denoted by Soil A, Soil B, and Soil C, were collected from three locations of the aggregate stockpile, and sieve analyses were conducted (see Figure 2.35). (a) (b) Figure 2.35 (a) Soil-aggregate stockpile; (b) sieve analysis (Courtesy of Khaled Sobhan, Florida Atlantic University, Boca Raton, Florida) a. Determine the coefficient of uniformity and the coefficient of gradation for Soils A, B, and C. b. Which one is coarser: Soil A or Soil C? Justify your answer. c. Although the soils are obtained from the same stockpile, why are the curves so different? (Hint: Comment on particle segregation and representative field sampling.) d. Determine the percentages of gravel, sand and fines according to Unified Soil Classification System.
An existing rural 4-lane highway is to be replaced by a 6-lane divided expressway (3 lanes in each direction). Traffic volume data on the highway indicate that the AADT (both directions) during the first year of operation is 24,000 with the following vehicle mix and axle loads. Passengercars=50percent 2-axle single-unit trucks (12,000lb/axle)=40percent 3-axle single-unit trucks (16,000lb/axle)=10percent The vehicle mix is expected to remain the same throughout the design life of 20 years, although traffic is expected to grow at a rate of 3.5 percent annually. Using the AASHTO design procedure, determine the minimum depth of concrete pavement required for the design period of 20 years. Pi=4.5J=3.2Pt=2.5Cd=1.0Sc=650lb/in.2So=0.3Ec=5106lb/in.2R=95k=130lb/in.3
In concrete work, Fuller and Thompson (1907) suggested that a dense packing of grains can be achieved if the percent finer (p) and grain size (D) are related by the following equation, where n is a constant varying in the range of 0.3-0.6. Dmax is the size of the largest grain within the soil. p=(DDmax)n100 This equation is sometimes used in roadwork for selecting the aggregates. a. For n = 0.5, show that the soil is well graded. b. If n = 0.5 and Dmax = 19.0 mm, find the percentages of gravel, sand, and fines within the soil. Use the Unified Soil Classification System.
A soil element beneath a pave ment experiences principal stress rotations when the wheel load, W, passes over it and moves away, as shown in Figure 10.51. In this case, the wheel load has passed over points A and B and is now over point C. The general state of stress at these points is similar to the one shown by a stress block at point D. The phenomenon of principal stress rotation influences the permanent deformation behavior of the pavement layers. Investigate how the magnitude and the orientations of the principal stresses vary with distance from the point of application of the wheel load. Consider the case shown in Figure 10.51. An unpaved aggregate road with a thickness of 610 mm and unit weight of 19.4 kN/m3 is placed over a soil subgrade. A typical single-axle wheel load, W = 40 kN, is applied uniformly over a circular contact area with a radius of R = 150 mm (tire pressure of 565 kN/m2). The horizontal and shear stresses at each point are calculated from a linear elastic finite element analysis for a two-layer pavement and are presented in the following table. a. Use Eq. (10.28) to calculate the vertical stress increases at soil elements A, B, and C that are located at radial distances 0.457,0.267, and 0 m, respectively, from the center of the load. Determine the total vertical stress (y) due to wheel load, the overburden pressure at each point, and enter these values in the table. b. Use the pole method to determine the maximum and minimum principal stresses (1 and 3) for elements A, B, and C. Also determine the orientation (s) of the principal stress with respect to the vertical. Enter these values in the table. c. Plot the variations of 1 and s, with normalized radial distance, r/R, from the center of loading.

Recommended textbooks for you

Traffic and Highway Engineering

Civil Engineering

ISBN:

9781305156241

Author:

Garber, Nicholas J.

Publisher:

Cengage Learning

Construction Materials, Methods and Techniques (M…

Civil Engineering

ISBN:

9781305086272

Author:

William P. Spence, Eva Kultermann

Publisher:

Cengage Learning

Principles of Geotechnical Engineering (MindTap C…

Civil Engineering

ISBN:

9781305970939

Author:

Braja M. Das, Khaled Sobhan

Publisher:

Cengage Learning

Traffic and Highway Engineering

Civil Engineering

ISBN:

9781305156241

Author:

Garber, Nicholas J.

Publisher:

Cengage Learning

Construction Materials, Methods and Techniques (M…

Civil Engineering

ISBN:

9781305086272

Author:

William P. Spence, Eva Kultermann

Publisher:

Cengage Learning

Principles of Geotechnical Engineering (MindTap C…

Civil Engineering

ISBN:

9781305970939

Author:

Braja M. Das, Khaled Sobhan

Publisher:

Cengage Learning

Fundamentals Of Construction Estimating

Civil Engineering

ISBN:

9781337399395

Author:

Pratt, David J.

Publisher:

Cengage,

Fundamentals of Geotechnical Engineering (MindTap…

Civil Engineering

ISBN:

9781305635180

Author:

Braja M. Das, Nagaratnam Sivakugan

Publisher:

Cengage Learning

Solid Waste Engineering

Civil Engineering

ISBN:

9781305635203

Author:

Worrell, William A.

Publisher:

Cengage Learning,

SEE MORE TEXTBOOKS