Authors :
Amadi, C.C., Okeke, O.C., Onyekuru, S. O., Okereke, C.N., Israel, H.O., Ubechu, B.O
Volume/Issue :
Volume 6 - 2021, Issue 11 - November
Google Scholar :
http://bitly.ws/gu88
Scribd :
https://bit.ly/3lIB7cN
Abstract :
Stabilization of expansive soils from Enugu
Shale, in Enugu Area Southeastern Nigeria with lime,
cement and coal fly ash admixtures were investigated with
the aim of improving the engineering behavior of
expansive soils. Samples of expansive soils were treated
with lime, cement and coal fly ash admixtures. Lime and
cement are chemical additives while coal fly ash is a
pozzolan .Engineering performance of treated soils were
evaluated using Atterberg limits, California bearing ratio
and Maximum dry Density .The Atterberg limits of
untreated soil were 42.0%, 22.55% and 4.3% for Liquid
limit, Plasticity index and Linear shrinkage . The
California bearing ratio of untreated soil was 2.3% and
1.1% for usoaked and soaked expansive soils. The
Maximum Dry Density of untreated soil was 1.32 Mg/m3
.According to the Casagrande’s plasticity chart, the soil
plots as inorganic clay of medium plasticity which
necessitated the need for chemical treatment. The
stabilization result showed reduction percentages of
29.76% % (42.0 to 29.5), 56.67% (42.0 to 18.20) for
cement, cement-coal fly ash mixes on liquid limit. Also a
maximum reduction of 21.43% (42.0 to 33.0), 30.95%
(42.0 to 31.2 %) on liquid limit for lime lime-coal fly ash
mixes respectively. A higher reduction percentage on
plasticity index for cement, cement-coal fly ash mixes and
lime and lime-coal fly ash were established as 90.67 %
(22.5 to 2.10 ), 96 % (22.5.5 to 0.90) and 54.67%(22.5 to
10.2),71.56%(22.5 to 6.4) . A remarkable increase in
California bearing ratio value of approximately 400 to
500% ,300 to 700% and 300 to 700, 350 to 900% increase
in strength gain for lime, lime-coal fly ash and cement,
cement-coal fly ash mixes respectively for unsoaked soil
samples. Also a strength gain of 100 to 180%, 100 to 200%
and 100 to 200%, 100 to 300% was achieved for Lime,
Lime-Coal Fly ash and ce ment, ce ment coal fly ash
samples respectively for soaked samples..The Maximum
Dry Density showed the highest percentage increase of
543.95%(1.32 to 8.50 Mg/M3
) and 875.76%(1.32 to 12.88
Mg/M3
) for cement and cement-coal fly ash mixes, and an
increase of 415.15%(1.32 to 6.8 Mg/M3
) and
642.42%(1.32-9.8 Mg/M3
). Treatment of the soil resulted
in increased strength and reduced swelling potential,
however, portland cement provided highly effective clay
stabilization, usually with the added benefit of higher
strength gain when combined with CFA.
Keywords :
Expansive soil, Cement, Lime, Coal Fly ash, Stabilization CBR, Atterberg limits, Pozzolan
Stabilization of expansive soils from Enugu
Shale, in Enugu Area Southeastern Nigeria with lime,
cement and coal fly ash admixtures were investigated with
the aim of improving the engineering behavior of
expansive soils. Samples of expansive soils were treated
with lime, cement and coal fly ash admixtures. Lime and
cement are chemical additives while coal fly ash is a
pozzolan .Engineering performance of treated soils were
evaluated using Atterberg limits, California bearing ratio
and Maximum dry Density .The Atterberg limits of
untreated soil were 42.0%, 22.55% and 4.3% for Liquid
limit, Plasticity index and Linear shrinkage . The
California bearing ratio of untreated soil was 2.3% and
1.1% for usoaked and soaked expansive soils. The
Maximum Dry Density of untreated soil was 1.32 Mg/m3
.According to the Casagrande’s plasticity chart, the soil
plots as inorganic clay of medium plasticity which
necessitated the need for chemical treatment. The
stabilization result showed reduction percentages of
29.76% % (42.0 to 29.5), 56.67% (42.0 to 18.20) for
cement, cement-coal fly ash mixes on liquid limit. Also a
maximum reduction of 21.43% (42.0 to 33.0), 30.95%
(42.0 to 31.2 %) on liquid limit for lime lime-coal fly ash
mixes respectively. A higher reduction percentage on
plasticity index for cement, cement-coal fly ash mixes and
lime and lime-coal fly ash were established as 90.67 %
(22.5 to 2.10 ), 96 % (22.5.5 to 0.90) and 54.67%(22.5 to
10.2),71.56%(22.5 to 6.4) . A remarkable increase in
California bearing ratio value of approximately 400 to
500% ,300 to 700% and 300 to 700, 350 to 900% increase
in strength gain for lime, lime-coal fly ash and cement,
cement-coal fly ash mixes respectively for unsoaked soil
samples. Also a strength gain of 100 to 180%, 100 to 200%
and 100 to 200%, 100 to 300% was achieved for Lime,
Lime-Coal Fly ash and ce ment, ce ment coal fly ash
samples respectively for soaked samples..The Maximum
Dry Density showed the highest percentage increase of
543.95%(1.32 to 8.50 Mg/M3
) and 875.76%(1.32 to 12.88
Mg/M3
) for cement and cement-coal fly ash mixes, and an
increase of 415.15%(1.32 to 6.8 Mg/M3
) and
642.42%(1.32-9.8 Mg/M3
). Treatment of the soil resulted
in increased strength and reduced swelling potential,
however, portland cement provided highly effective clay
stabilization, usually with the added benefit of higher
strength gain when combined with CFA.
Keywords :
Expansive soil, Cement, Lime, Coal Fly ash, Stabilization CBR, Atterberg limits, Pozzolan
