INCREASE ON STRENGTHS OF HOT WEATHER CONCRETE BY SELF-CURING OF WET POROUS AGGREGAT
ABSTRACT: Generally, a
concrete made in hot weather usually accompanied by a decrease of compressive
and tensile strengths. The loss of much combined water in the concrete body is
mostly caused by high evaporation of water or moisture during a period of fresh
and hardened concrete. An alternative was needed to cope with this problem. Wet
porous aggregate which holds much water than wet ordinary aggregate may solve
the problem. Porous aggregate of flyash aggregate usually used in a lightweight
concrete is generally linked to low strengths of concrete, but when use it in
wet (saturation) condition the aggregate could provide favourable strengths of
concrete. An absorbed water within the flyash aggregate, different with
combined water in mix design to determine W/C ratio, moves out to the cement
paste which has already hardened, thereby, continuing the hydration process. This
mechanism is called “self curing” and would intensify much products of
hydration therefore increas-ing the strengths. Experiment was done in the room
temperature ranged from 20°C to 40°C and with constant at a relative humidity.
The results, the self curing occurred within the body of concrete using flyash
aggregate, as wet porous aggregate, had provided the higher compressive and
tensile strengths compared with concrete using silane flyash and crushed stone aggregates.
Even in the high air temperature the self curing gave favourable effect on the
compressive and tensile strengths as it contributes a better bond strength
around the aggregate of flyash.
Author: Victor Sampebulu
Journal Code: jptsipilgg110019
