THE EFFECT OF CARBON DIOXIDE AND STEAM IN STRENGTH OF MODIFIED TRONOH'S MINING SAND USING QUICKLIME

Nowadays, ex-mining locations in Tronoh were being developed and their tailing sand is
widely used in industry such as in ceramic and glass manufacturing, in manufacture of
calcium silicate bricks and as fill material in highway construction project. The objectives
of this project is to determine the optimum lime content at maximum compaction used to
modify Tronoh's mining sand and their undrained shear strength by 2two conditions which
is further treated by using carbon dioxide at 20 psi and I 00°C of steam and without carbon
dioxide and steam by curing period. Laboratory experiments that have been carried out in
this project are sieve analysis, compaction test, addition of carbon dioxide and steam in
mining sand-lime mixes and unconfined compression test. Sieve analysis indicates that
sample ofTronoh's mining sand is classified in poorly graded sand. Optimum lime content
of I 0% at maximum dry density of 2.0178 Mg/m 3 and 8% optimum moisture content was
used in every mixes. Then the strength of mining sand-lime mixes was compared with
sand-lime-C02-steam mixes by curing period. The results indicated that undrained shear
strength of sand-lime mixes is increase by curing, 29.5 kPa for 3 days to 275.36 kPa for 28
days. Undrained shear strength between sand-lime mixes with addition of carbon dioxide
and steam by curing period were compared. Results indicated that immediate undrained
shear strength of sand-lime mixes increase by duration of 1, 2 and 4 hours addition, where
I hour test give 201.19 kPa, 203.47 kPa for 2 hours test and 232.75 kPa for 4 hours.
Besides, increase in curing period of these mixes will increase their undrained shear
strength of 2 hours test by 301.42 kPa for 3 days curing to 407.59 kPa for 7 days curing.
Strength of 4 hours test give higher strength compared to 2 hours test which increase from
351.46 kPa for 3 days curing to 413.55 kPa for 7 days curing. This data can be used as
references when strength is concerned in construction and manufacturing.
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