|
The Idiots' Guide to Highways
Maintenance
Copyright © 2000/10, C.J.Summers
|
CORES TAKEN FROM VARIOUS
TYPES OF ROAD PAVEMENTS, A CLOSE STUDY
If
any one tells you they have no records on a particular road pavement they are
only telling you half the truth.
You may not be able to determine the points in time when particular events took
place in the history of the road pavement and you may not have the costs of the relevant
repairs or procedures that took place. But nearly everything else you will be
able to determine by the cross section through the road itself.
You are able to determine the various layers, the thickness, and the actual
materials themselves by isolating particular layers and analysing them, and you can
even reclaim the binder and determine its penetration and softening
point.
Just about everything is possible if you have the will and the resources, and of
course the knowledge of how to go about things. Your Materials Engineer should
be able to assist in these matters.
THIS PAGE MAY TAKE SOME
TIME TO LOAD BECAUSE OF THE NUMBER OF LARGE IMAGES TO BE DISPLAYED,
BUT THE DETAIL SHOWN WILL GIVE GOOD INSIGHT IN TO THE NATURE OF ROAD PAVEMENT
CONSTRUCTION AND THE TYPE OF MATERIALS USED.
 |
Above is a picture of a
200mm. core of 30% 14mm. design hot rolled asphalt, if you look closely on
the top (in fact the bottom) of this core you will see a slight
indentation from a wheel track test, it clearly passed.
Note, the bulk of the matrix is sand, bitumen and limestone filler.
|
 |
There
should be no voids in a true stone mastic asphalt, as shown in the image
above the voids should be filled with mastic.
The mastic consisting of bitumen (50pen. most often specified), usually with
a small percentage (0.3% often specified) cellulose fibres to improve
aggregate coating and to prevent binder drainage, and some smaller grit that
is permitted in the overall grading of the aggregate. |
[ Top of Page ]