Abstract
The objective of the thesis is to use industrial wastes
rather than natural soil, aggregates, etc. in roads and highway
construction after enhancing its strength, stability and durability.
Conventionally, soil, stone aggregates, sand, bitumen, cement etc.
are used in construction of roads and highway. Characteristic
materials being limited in nature and thereby need of alternate
materials is necessary. Gigantic quantities of soil are utilized as a
part of the development of street and parkway yet adequate
quantity of soil of required quality is not available effectively. To
meet this demand extensive deforestation is being done which
cause deforestation, soil disintegration and loss of rich soil which
hampers in the farming efficiency. Additionally, cost of
procurement of suitable quality of material is increasing.
Worried about this, the researchers are searching for option
materials for thruway development, and modern waste item is
one such class. Stabilization method highlighted in this thesis is
mainly to enhance the inherent strength of wastes like fly ash and
crushed blast furnace slag (CBFS). This will automatically
reduce the use of natural soil in addition to mitigate the disposal
problems of industrial solid wastes in a great way. Fly ash and
blast furnace slag was collected from Bokaro steel plant (BSP).
Tests were conducted by blending fly ash and blast furnace slag
in different proportions. The compaction characteristics,
strength properties and the bearing value of different mixes are
determined. From the compaction tests the optimum moisture
content and the maximum dry density are determined for
respective mixes. The strength parameters that are the
unconfined compressive strength and CBR value for different
mixes compacted to their respective MDD at OMC are evaluated.
Further these mixes are blended with lime varying as 0%, 2%,
4%, and 8% and the UCS values are determined after a curing
period of 0, 7 and 28 days. Similarly, the soaked CBR values of
lime stabilized mixes at 0%, 2%, 4%, and 8% are determined
after a curing period of 0 and 28 days. The effect of lime, curing
period, fly ash and slag content with the unconfined compressive
strength values and California bearing ratio values were studied.
From the experimental study, it was observed that with addition
of blast furnace slag to fly ash- slag mixes, the MDD increases
and thereby decreases its OMC value linearly. It was also
observed that the UCS value of the fly ash- slag mixes increases
with the addition of slag up to slag content of 80% and there
after the same decreases with further increases in slag content.
The mix with 80% slag shows higher value as compared to 100%
slag in the mix. Similar trend was observed for the CBR value for
the fly ash- slag mixes, and it was seen that with increase with the
slag content the CBR values also increases. However, for 100%
slag the CBR shows a lesser value. Higher UCS and CBR values
were reported at 8% lime content having a curing period of 28
days. The objective of the present study is to access the suitability
of lime stabilized fly ash- blast furnace slag mixes as a highway
construction material. So it is concluded that appropriate
blending of fly ash with slag gives a better strength compared to
individual materials. Further the desired strength required for
different component of road can be achieved by stabilizing the
mix with appropriate amount of lime.