| dc.description.abstract |
This research used normal strength cylinder concrete included three
different sizes with Ф5×10 cm、Ф10×20 cm and Ф15×30 cm to compare with
each other.
After casted in cylinder model for four hours in air to finish initial setting
program, removed the form immediately then put specimens into pressure
chamber which injected the high carbon dioxide gas to start doing the fast curing
test with factors included three carbon dioxide concentrations, three curing time
and two curing pressures. Finally, put carbonated specimens in the saturated
limewater to keep after curing. This research will discuss compressive strength,
elastic modulus and neutral degree for different cylinder concrete sizes in
different environment factors of CO2 curing. After that, the experiment of
rupture modulus was run by choosing a CO2 curing factor for higher
compressive strength.
According to the result, the compressive strength of specimen size and
curing duration by different CO2 curing factors was different; however, the
effect of specimen size is apparent in the same CO2 curing factor. The
compressive strength of Ф5×10-cm specimens was higher than other two sizes
about 13% in the 90-day water curing. After CO2 curing, the amplification
coefficient of CO2 curing excluded the size effect from water curing was 30%.
No matter CO2 curing or not, or the size effect, the difference of elastic
modulus was less than 5%. After CO2 curing, the modulus of rupture was similar
to the water-curing one and the depth of carbonation reached a depth of 1.71
mm. The optimal compressive strength of Ф15×30-cm specimen by curing was
50% CO2 concentration, 1 hour curing and 2 bar pressure. The compressive
strength of CO2-cured specimens at 3, 7, 28 and 90-day duration was higher than
the water-curing ones about 29%, 38%, 8% and 11%, respectively. | en_US |