Environmental Engineering Reference
In-Depth Information
some difficulty, so a less restrictive value of k = 2.5
has been suggested, with excellent granular layer
structural performance.
experimental field testing has clearly identi-
fied that the efficiency of the densification proc-
ess is influenced by the mechanical properties of
the supporting layer. compaction on insufficient
foundation stiffness produces dissipation of the
compaction energy into the underlying courses
without increasing the rate of densification of
the new unbound granular base layer. in this
field experimental research a empirical correla-
tion between effective Modulus of the support
(obtained from FWD tests) and rate of compac-
tion of the employed volcanic material has been
suggested, verifying that standard specifications
generally required by technical codes (relative
compaction >98% of P.M. maximum dry density)
only can be achieved for greater subgrade stiffness
than 110-120 MPa (e2 subgrade quality, according
to currently spanish Pavement standard 6.1-ic).
ReFeRences
asociación española de normalización aenoR. 2003.
Áridos para capas granulares y capas tratadas con con-
glomerantes hidráulicos para su uso en capas estruc-
turales de firmes
. Une-en 13242:2003. Madrid:
aenoR.
comité Français pour les Techniques Routièrs. 1994.
Assises de chaussées. Graves non traitées. Définition.
Composition. Classification
. nF P 98-129:1994. Paris:
cFTR.
comité Français pour les Techniques Routièrs. 2006.
Mise en application de la nouvelle norme grave non
traitée
. nF en 13285: 2006. Paris: cFTR.
european committee for standardization cen. 2003.
Unbound mixtures. Specification
. en 13285:2003.
Bruxelles: cen.
estradas de Portugal. 1998.
Cuaderno de Encargos
5-03 Pavimentação
. ePe-98. lisboa: eP.
Franesqui, M.a. & castelo, F. 2009. Áridos volcánicos
en capas granulares no tratadas: control de la com-
pactación e influencia de la rigidez del cimiento.
Car-
reteras
164: 34-47.
hawaii Department of Tansportation hDT. 2005.
Stand-
ard Specifications. 304-Aggregate base course
.
instituto Português da Qualidade iPQ.
Agregados para
materiais não ligados ou tratados com ligantes hidráuli-
cos utilizados em trabalhos de engenharia civil e na con-
strução rodoviária
. nP en 13242:2005. lisboa: iPQ.
Ministére des Transports. Direction des routes. 1984.
Mémento
des spécifications francaises. Chaussées
. Paris: MT.
Ministerio de Fomento. Dirección General de carreteras.
2004.
Pliego de Prescripciones Técnicas Generales para
Obras de Carreteras y Puentes. 510-Zahorras
. orden
Ministerial FoM/891/2004.
acknoWleDGeMenTs
The authors thank to the contractor Marques,
sa, for their permission to use information from
various unpublished reports. special thanks to
Dr. Petur Petursson for the information about
iceland specifications and to Dr. letizia de lan-
noy kobayashi for the information about hawaii
specifications.
