CONSTRUCTION OF ROADS
Learning outcomes of the course unit
Knowledge and understanding:
At the end of this course the student should know the basics on road
design and construction.
Applying knowledge and understanding:
The student should be able to evaluate the best solution of extra-city
road trunk and adopt appropriate materials for the construction attending
the best practice.
By the end of the course, the student should be able to design, with
critical mind, a section of road and choose the best solutions to construct
embankments and pavements.
The student should be able to clearly present an transportation
infrastructure design also by means of tables and charts.
It is useful to have done Geotechnics course.
Course contents summary
The course aims to give the basis for the geometric design of road structures and the choice of materials an realization of road construction.
1) ROADS AND VEHICLE: Resistances to motion. Locomotion mechanic and general equation for traction. Friction: coefficient of friction fa. Lamm-Herring relationship. Stopping sight distance. Overtaking sight distance. Road vehicles performances. Perception of road environment.
2) ROAD DESIGN IN HORIZONTAL PLAN: D.M. 5/11/2001 Design speed. Road axis. Horizontal plan. Vehicle stability on curve. Visibility in curve. Superelevation in curve: maximum transversal friction criterion, maximum transversal gradient criterion, proportionality criterion. Definition of Nomogramma of CNR (curvilinear method). Calculation ofhorizontal radius by mean of optical criteria: horizontal sight distance along the inside of a curve. Stopping sight distance and passing sight distance. Spiral (transition curve): intrinsic equation, Cartesian coordinates equation: Fresnel integrals, series expansions.
3) VERTICAL ALIGNMENT OF ROAD: Maximum grade of vertical alignment. Vertical circular and parabolic curves. Horizontal and vertical coordination.
4) ROAD CROSS SECTION: Road cross section according to CNR. Characteristics of road cross section. Particular road cross section. Road cross section in curve. Curve enlargement. Variation of road cross section in curve. Definition of relative minimum slope “i”.
5) ROAD STRUCTURE CONSTRUCTION: Definition of soils as material for embankments. Embankment. Excavation. Subgrade.
6) ELEMENTS OF ROAD GEOTECHNICS: Fundamental parameters of soils: grading analysis, compressibility, shear strength. Water susceptivity, Atterberg limits: LL, LP, LR, IP. Soils classification: Index group, HRB, FAA. Soils compaction. Soils compaction in (s,W) chart. Proctor and AASHTO test.
7) STONE AGGREGATES: Classification of stone aggregates. Required characteristics. Shape characteristics. Test on aggregates: grading analysis, Deval, microdeval, Los Angeles, dynamic crushing , CPA, sand equivalent, ice susceptivity. Aggregate characteristic referred to its employment: subbase, base, binder, wearing course. Sand and filler characteristics.
8) BINDERS: Binders: bitumen, coal tar, asphalt. Organic binders with polymers, oxidized bitumen, cut-back asphalt, bituminous emulsions. Controls on bituminous binders: penetration, ring and ball temperature,
Frass temperature, viscosity. Heukelom abaci. Thermal susceptivity. Stiffness modulus. Bitumen-aggregate adhesion.
9) MIXTURES FOR ROAD STRUCTURES: Mechanical characteristics of mixtures. Granular mixes subbase. Soil stabilisation for subbase. Bounded and non-bounded for base layers. Bituminous mixtures. Design of optimum grading curve: Fuller curve and grading distribution. Percentage of filler. Determination of binder percentage: English method (voids method), French method (specific surface or Duriez).
10) ROAD PAVEMENTS DESIGN: Traffic loads: coefficient of axis equivalence, vehicle speed. Types of road pavements: flexible, rigid and semi-rigid. Mechanical characteristics of layers: subgrade, subbase, base, binder and bituminous wearing course, cement concrete pavements.
Environmental conditions influence. Pavement design. Empirical design: AASHO, Interim Guide, Road Note 29. Rational design for pavement design: stress-strain analysis, fatigue calculation, rutting calculation.
P.FERRARI, F.GIANNINI: Geometria e progetto di strade Vol. 1° e Vol. 2° I S E D I
Additional books: G. TESORIERE:Strade ferrovie aeroporti Vol. 1° e Vol. 2° UTET
Additional educational material available on the University web learning
site “Web LEArning in Ateneo” (LEA UNIPR): Lecture slides. Text of all the
Slides will be used to show the most important messages of the theory
lectures. Classroom numerical exercitation will done and students will see
experiments on road materials during by laboratory sessions. Before
each experiment a lecture will introduce the objectives and the
theoretical aspects of the studied phenomena.
Assessment methods and criteria
The examination is based on a written exam with three questions on
The demands are releated to chapters:
question 1 1-2-3-4
question 2 5-6-7
question 3 8-9-10
Lecture attendance is highly recommended.