Geoscience Reference
In-Depth Information
binder. Figure
367
shows sand carpet from a bridge deck.
It consists of natural sand fine aggregate (with no coarse
aggregate) bound by a relatively high content of
bitumen. Figures
368
and
369
show a grouted macadam
from a car park, consisting of open textured asphalt with
the voids filled by cementitious mortar. The cementitious
mortar comprises 25% of the material and contains an
addition of microsilica. Figure
370
shows a bituminous
bedding material of an historic wood block floor (circa
1810). The material comprises a mixture rich in bitumen
(possibly a natural bitumen) combined with a natural
sand fine aggregate.
367
368
367
Sand carpet comprising bitumen (black) mixed
with natural sand fine aggregate (white). Small air
voids are shown yellow; PPT, ×150.
368
Grouted macadam with crushed rock coarse
aggregate (intermediate igneous rock, white/light
brown), coated by bitumen (black). Large voids filled
by microsilica improved sand:cement mortar with the
sand particles appearing white (lower right). Small
voids are unfilled and shown yellow; PPT, ×35.
369
370
369
Grouted macadam with crushed rock coarse
aggregate (intermediate igneous rock, grey), coated by
bitumen (brown, centre). Large voids are filled by
microsilica improved sand:cement mortar (black,
lower left) with the sand particles appearing white;
XPT, ×35.
370
Historic bituminous floor bedding, with natural
sand consisting of quartz (grey/white) and phosphatic
rock particles (brown), bound by bitumen (black);
XPT, ×35.