PURPOSE: To obtain cement for excavation which makes it possible to obtain high-pressure compression stress and nonporosity by using a slurry by formulating specific plastic powder at the time of preparing the slurry of the cement for excavation contg. a hydraulic binder.
CONSTITUTION: The cement for excavation contg. the hydraulic binder as a component contains the plastic powder of 50 to 800 kg for each 1 m3 of the slurry. The plastic powder comprises hard and alkali resistant particles of ≤2 mm in grain size. The plastic powder is the powder which does not substantially contain fillers and further retains the tensile strength without drastic degradation unless the temp. higher than by at least 10°C than the intrinsic max. static pore hole temp. in excavation is attained. The hydraulic binder is preferably Portland cement, slag cement, high-alumina cement or the like. The plastic powder having a grain size distribution contg. at least 90% of the particles below 1 mm is preferable.
ADARUBERUTO HERUMAN
REDEIGERU OBERUSHIYUTEPATOBERU
