| 摘要 |
PURPOSE:To enable control of a temperature of cooled fresh concrete reliably, efficiently and freely, by a method wherein a coarse aggregate is cooled by dipping the same into low-temperature liquefied gas within a low-temperature liquefied gas tank and the same is loaded into a concrete mixer along with a constituent material of concrete such as a noncooling fixed-temperature coarse aggregate and the others. CONSTITUTION:About one third of a coarse aggregate 6'' is measured by a measuring hopper 8 and loaded within an low-temperature liquefied gas tank 11. The loaded aggregate 6'' is dipped into liquid nitrogen 10 under a state where the same is mounted on a belt conveyor 12 and cooled suddenly. A cooling temperature is controlled by adjusting dwell time (dipping time) into the tank. The cooled aggregate 6 is loaded into a collecting hopper 14 along with a measured noncooling fixed temperature coarse aggregate 6'. The coarse aggregates 6, 6' whole quantity of which has gathered are loaded into a concrete mixer 16 through a forked damper 15 of the collecting hopper 14, and mixed up with a constituent material of concrete such as other water, sand and cement, kneaded, and fresh concrete is manufactured. |
