Science and Technology of Energetic Materials

Vol.62, No.5 (2001)

Research paper

Static demolition by calcium oxide
- Evaluation of demolition properties -(*in Japanese)
Hisaaki Fukui


The demolition of concrete or rocks was carried out with the two kind of static demolition agents consisting of CaO as the main ingredient.
The first type of the agent, the delay type cracked concrete or rocks after 12 hours, and it was guessed that the expansion pressure was needed to be over 300 kg / cm2. Split lines were observed in the cracks.
The second type, the rapid type cracked concrete of rocks after 30 to 60 minutes, and the expansion pressure was needed to be over 600 kg / cm2 and the occurrence velocity had to be over 300 kg / min. For the rapid type, it was recognized that water vapor with the vapor pressure of 10 kg / cm2 and the temperature of 150 ℃ played an important role.
It is suggested for the cracking mechanism by the rapid type that the pulsating motion of high pressure water vapor produced in a hole acts on concrete or rocks to migrate them.

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