Asphalt concrete is used in the surface layer of road paving and is widely used around the
world. Asphalt concrete consists of coarse aggregate , fine aggregate, filler and asphalt
binder. Fly ash FA is one of the main wastes of coal-fired thermal
and coal-fired power
plants and is available in large quantities and has no use. The aim of this study is to
evaluate the possibility of using fly ash as a filler material in hot asphalt mixtures and to
use it as an alternative to natural fillers by performing laboratory work in which the asphalt
mixture is designed and the optimal ratio of asphalt is determined . Then replace the filler
material with 0, 25, 50, 75 and 100% with fly ash . The results showed that Marshall's
stability values increased with increased replacement ratio and observed that Marshall's
hardness values were decreased while remaining within the tolerable limits of the
specifications. The study concluded that fly ash can be used as a filler in asphalt mixtures.
This experiment investigates the effect of aluminum powder as metallic filler of
unsaturated thermosetting polyester resin on the wear rate and its mechanisms according to
time.
The obtained results show that the rate of wear increases with increa
se of time as a
result of increase the temperature generated of friction in all specimens. But when we add
the particles either Aluminum to polyester matrix, the rate of wear reduce as a result of
increase the thermal conductivity of polyester matrix, that leads reduction of the
temperature of contact surface, that leads less wear. We study the mechanisms of wear by
microscope of the worn surface. It found that the predominant mechanisms of wear vary
from adhesive wear at the lowest value of test time to abrasive wear (3- body) at the
highest value of test time.
