Pavement Design
MANAGEMENT OF INFRASTRUCTURE
AND COMMUNITY DEVELOPMENT
What will you learn?

You will learn about types of pavement structure,
asphalt pavement design method, rigid pavement
design method
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
What competency do you want to expect?


Knowledge competency: You will recognize types
of pavement structure, asphalt pavement design
method, rigid pavement design method.
Skill competency: you are able to bridge
communication between community and
engineering service provider (road
planner/designer/contractor) in regards with
suitable pavement structure to support
development of community and region according to
cost availability and site condition
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Contents



Types of pavement structures
Asphalt pavement design method
Rigid pavement design method
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Cross section of roman road
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Types of pavement: roman road pavement
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Types of pavement: early modern road pavement
(Tresaguet, Telford, McAdam)
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Types of pavement: early modern road pavement
(Tresaguet, Telford, McAdam)
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Types of pavement: modern road pavement
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Details of rigid pavement joints
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Types of rigid pavement
(max. length of 6 m per slab)
(b) Jointed reinforced concrete
pavement (JRCP) (max. length
of 30 m per slab)
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Road construction on swamp and wetland area
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Haul road
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Asphalt pavement design method





Load distribution in asphalt pavement
Properties of flexible pavements
Design objectives and constraints
AASHTO, 1993 Design Method
Pavement damage
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Load distribution in asphalt pavement
Asphalt pav. is designed to provide sufficient
thickness to distribute the applied load with
depth
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Properties of flexible pavements











Fast Deterioration with Time
Repeated Loads
Variable Load Configuration
Variable Load Magnitude
Variable Tyre Pressure
Traffic Growth
Change of Material Properties with Environmental Conditions
Change of Subgrade Properties with Distance
Channelized Traffic Load
Multi-Layer System
Unconventional Failure Definition
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Design objectives
The objectives of pavement design can be listed as
follow
 Maximum economy, safety, and serviceability over
the design period
 Maximum or adequate load-carrying capacity in
terms of load magnitude and repetitions
 Minimum or limited deteriorations over the design
period
 Minimum or limited noise or air pollution during
construction
 Minimum or limited disruption of adjoining land use
 Maximum or good aesthetics
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
The constraints
The pavement designer typically faces several economic,
physical, and technical design constraints such as,
 Availability of time and fund for design and construction
 Minimum allowable level of serviceability before rehabilitation
 Availability of materials
 Minimum and maximum layer thickness
 Capabilities of construction and maintenance personnel and
equipment
 Testing capabilities
 Capabilities of structural and economic models available
 Quality and extent of the design data available
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
AASHTO, 1993 Design Method


Equivalent Single Axle Load (ESAL)
Design Procedure
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Equivalent Single Axle Load (ESAL)




Traffic loads applied on the pavement surface range from light passenger cars to heavy
trucks. To design a pavement section the damage caused by all axle loads that will be
applied on the pavement during its designed life has to be considered.
Different magnitudes and different numbers of repetitions are converted to an equivalent
number of repetitions of a standard axle load that causes the same damage to the
pavement. A standard axle load was selected as 18000 Lb (80 kN) applied on a single
axle with a dual wheel at each end.
The ESAL is the equivalent number of repetitions of the 18-kip (80 kN) standard axle load
that causes the same damage to the pavement caused by one-pass of the axle load in
question.
Equivalent Axle Load Factors (EALF) to relate the damage caused by different load
magnitudes and axle configurations to the standard axle load as shown in Equation
below
where Wt18 is the number of 18-kip (80-kN) single-axle load applications to time t
(failure) and Wtx is the number of x-axle load applications to time t (failure).
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Equivalent Axle Load Factors, Single axles
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Equivalent Axle Load Factors, tandem axles
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Equivalent Axle Load Factors, triple axles
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Equations to calculate pavement thickness





Lx is the load in kips on one single axle, one set of tandem axles, or
one set of triple axles;
L2 is the axle code (1 for single, 2 for tandem axles, and 3 for triple
axles);
pt is the terminal serviceability index
b18 is the value of bx when Lx is equal to 18 and L2 is equal to one.
SN is the structural numbers, which is an index that combines the
effect of material properties, layer thicknesses and drainage quality
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
ESAL at first day and cumulatif ESAL during design
life

ESAL at first day may be calculated as follow

Cumulatif ESAL during design life can be calculated as follow
where
 Ni is the number of repetitions of axle group i,
 EALFi is the equivalency factor for axle group
 m is number of axle groups
 n is the designed life of the pavement in years
 i is the expected annual traffic growth rate.
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Since the EALFs are not very sensitive to SN, a SN value of 5 may
be assumed in most cases. Unless the design thickness is
significantly different, no iterations will be needed
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Design Procedure












Step 1 — Reliability
Step 2 — Overall Standard Deviation
Step 3 — Cumulative Equivalent Single Axle Load
Step 4 — Effective Roadbed Soil Resilient Modulus
Step 5 — Resilient Moduli of Pavement Layers
Step 6 — Serviceability Loss
Step 7 — Structural Numbers
Step 8 — Structural Layer Coefficients
Step 9 — Drainage Coefficients
Step 10 — Layer Thicknesses
Step 11 — Freeze or Thaw and Swelling (additional)
Step 12 — Life-Cycle Cost (additional)
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Step 1 — Reliability

A reliability level (R) is selected depending on the
functional classification of the road and whether the
road is in urban or rural area. The reliability is the
chance that pavement will last for the design period
without failure. A larger reliability value will ensure
better performance, but it will require larger layer
thicknesses.
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Step 2 — Overall Standard Deviation

The overall standard deviation ðSoÞ takes into
consideration the variability of all input data. The
1993 design guide recommends an approximate
range of 0.4 to 0.5 for flexile pavements
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Step 3 — Cumulative Equivalent Single Axle Load


In this step, the designer assumes a designed life, typically in the range of 10
to 20 years. The cumulative expected 18-kip (80-kN) ESAL (W18) during the
designed life in the design lane is then determined as discussed earlier. If the
cumulative two-directional 18-kip ESAL is known, the designer must factor the
design traffic by directions by multiplying by the directional distribution factor
(D) to get the ESAL in the predominate direction. For example, if the traffic
split during the peak hour is 70 – 30%, D is taken as 0.7.
To get the ESAL in the design (right) lane, the design traffic in the
predominant direction is multiplied by the lane distribution factor (L)
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Step 4 — Effective Roadbed Soil Resilient Modulus
Worksheet for
estimating effective
roadbed soil resilient
modulus
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Step 5 — Resilient Moduli of Pavement Layers

The resilient moduli ðMRÞ of the surface, base, and
subbase layers are either determined using
laboratory testing or estimated using previously
developed correlations
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Step 6 — Serviceability Loss

The serviceability loss is the difference between the
initial serviceability index (po) and the terminal
serviceability index (pt). The typical Po value for a
new pavement is 4.6 or 4.5. The recommended
values of pt are 3.0, 2.5 or 2.0 for major roads,
intermediate roads and secondary roads,
respectively
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Step 7 — Structural Numbers

The required structural number above the subgrade
(SN3) is determined using following equation (that
also can be described using the figure).
Figure 8.22
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Step 8 — Structural Layer Coefficients


The structural layer coefficient is a measure of the relative
ability of a unit thickness of a given material to function as a
structural component of the pavement.
Three structural layer coefficients (a1, a2 and a3) are required
for the surface, base and subbase, respectively.
Chart for estimating structural
layer
coefficient of dense-graded
asphalt concrete based on
the elastic (resilient) modulus
(a1)
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Chart for estimating structural
layer
coefficient of base course (a2)
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Chart for estimating structural layer coefficient of sub
base (a3)
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Step 9 — Drainage Coefficients

Drainage coefficients are measures of the quality of
drainage and the availability of moistures in the
granular base and subbase
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Step 10 — Layer Thicknesses

Minimum Thickness (in.) (AASHTO, 1993)
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Sample Problem 1
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Solution
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Solution (continued)
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Solution (continued)
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Rigid pavement design method







Characteristics and Load Transmission of
Rigid Pavements
Considerations for Structural Design of
Rigid Pavement
Computation of Design Traffic Loading
Material Properties for Design of Rigid
AASHTO Procedure for Thickness Design
of Concrete Pavement
Reinforcement Design of Rigid Pavement
Joints and Load Transfer Design
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Characteristics and Load Transmission of Rigid
Pavements
The rigid pavement relies on rigid slab action and
designed to spread the load over a large area
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Considerations for Structural Design of Rigid
Pavement
(a) Determination of soil properties, design traffic
loadings and environmental parameters
(b) Selection of materials for various pavement layers
(c) Structural thickness design of pavement layers
(d) Drainage design for the pavement system
(e) Safety and geometric design
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Computation of Design Traffic Loading
The computation of design traffic loading involves the following
steps:
(a) Estimation of the initial year traffic volume and composition
(b) Estimation of the annual traffic growth rate by vehicle type
(c) Estimation of directional split of design traffic
(d) Estimation of design lane traffic
(e) Estimation of the magnitudes of wheel loads by vehicle type
(f) Computation of the number of applications of wheel loads in
the design lane

Information concerning (a) and (b) can be obtained from traffic
survey and forecast based on historical trends or prediction
using transportation models.
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Computation of Design Traffic Loading
Directional Split and Design Lane Traffic Loading
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Computation of Design Traffic Loading
Traffic Loading Computation:
 Structural analysis and design of pavement requires the knowledge
of (a) the magnitudes of axle loads in the design traffic, and (b) the
number of times each of these loads will be applied on the design
lane during the design life of the pavement.
 Two forms of field survey are required to obtain the required
information from similar highway type within the same region.
First, traffic count surveys must be conducted to determine the
number of vehicle types in the design traffic. For pavement design, it
is necessary to classify vehicles by size and axle configuration, such
as cars, buses, single-unit trucks, and different types of multiple-unit
trucks.
Second, a survey to measure the axle or wheel loads of each vehicle
type. Such axle or wheel load survey can be performed at weighing
stations or using weigh-in-motion devices. Data collected from the
two forms of survey enable one to compute the number of repetitions
by axle type
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Vehicle Classification for Pavement Design
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Example of Axle Load Data for Pavement Design
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
ESAL factor in rigid pavement design
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
AASHTO Load Equivalency Factors for Rigid Pavements Based on
Terminal Serviceability Index of 2.5 for Tandem Axles and pt of 2.5
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
AASHTO Load Equivalency Factors for Rigid Pavements Based on
Terminal Serviceability Index of 2.5 for Tandem Axles and pt of 2.5
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
AASHTO Load Equivalency Factors for Rigid Pavements Based on Terminal
Serviceability Index of 2.5Triple Axles (i.e., Tridem Axles) and pt of 2.5
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
AASHTO Load Equivalency Factors for Rigid Pavements Based on Terminal
Serviceability Index of 2.5Triple Axles (i.e., Tridem Axles) and pt of 2.5
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Sample problem 2
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Sample problem 3
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Formula for Computing Total Design Loading
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Sample problem 4
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Material Properties for Design of Rigid Pavement
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
AASHTO Procedure for Thickness Design
of Concrete Pavement: Procedure





Reliability
Pavement Material Properties
Load Transfer Coefficient
Drainage Coefficient
Slab Thickness Requirement
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Reliability
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Chart for estimating composite k
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Chart for k as a function of bedrock depth
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Chart for estimating relative damage to rigid pavements
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Correction of effective modulus of subgrade reaction for
potential loss of subbase support
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Values for Loss of Support Factor LS
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Sample problem 5 and 6

Sample problem 5

Sample problem 6
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Load Transfer Coefficient
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Drainage Coefficient
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Slab Thickness Requirement and sample problem 7

Sample problem 7
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Rigid pavement thickness design chart
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Reinforcement Design of Rigid Pavement
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Reinforcement Design for JRCP
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT
Sample problem 8
MANAGEMENT OF INFRASTRUCTURE AND COMMUNITY DEVELOPMENT