Taisei Corporation

Other

Yasuro Ito

Hideharu Kaga

Yasuhiro Yamamoto

Tadayuki Sumita

Yoshiro Higuchi

Mitsutaka Hayakawa

Kenji Kuroha

Yutaka Mochida

Masanori Tsuji

Yasunori Matsuoka

Takakazu Ishii

Kuniomi Suzuki

Eiichi Tazawa

Seiji Kaneko

Sampei Kemmochi

Norio Marushima

In the preparation of a cement paste about 30 to 76% of the total water is added to the cement to form a funicular state, capillary state or slurry state, and the resulting mixture is kneaded so as to reduce the coagulated lumps of cement. Then the remaining quantity of water is added and the composition or mixture is kneaded again. Sand and/or gravel may be incorporated after the firstly kneaded mixture. The resulting cement paste, mortar or green concrete exhibits a small percentage of bleeding water and products prepared therefrom have a high compression strength.

Method of preparing kneaded compositions

A plurality of moulds each including a side frame and a hollow bed overlying the side frame are vertically stacked with sealing members interposed between the beds and the side frames for hermetically sealing the moulds. While the pressure in the moulds is being reduced a hydraulic substance such as cement is poured into the moulds. The poured hydraulic substance is heat cured to produce solid articles releasable from the moulds. An empty mould is added to one side of the stack while a mould containing the cured substance is removed from the other side of the stack. Alternatively, the process can be carried out according to a batch system. The moulds may be packed with aggregate, fittings or means for interconnecting the articles.

Method and apparatus for manufacturing articles of hydraulic substances

A green concrete mortar is prepared by the steps of preparing a first composition in which water is uniformly deposited about the particles of sand, preparing a second composition consisting of a powder of cement, mixing together the first and second compositions, thus forming stable shells about the particles of the sand, the shells having substantially a constant ratio of water to cement, and adding water to the shelled sand and then kneading the resulting mixture. The green concrete mortar can be poured into a moulding frame prepacked with a coarse aggregate i.e. gravel. After incorporating gravel into the mortar, the resulting green concrete can be moulded or blasted. The green concrete can be readily conveyed to a working station for constructing tunnels, buildings or the like.

Method of preparing green compositions containing a hydraulic substance

A slurry shaped freshly mixed fluid compound such as paste or mortar and coarse or fine aggregate are conveyed under pressure through discrete conduits and then mixed together substantially immediately before blasting. The mixture is blasted through a nozzle against a body to be covered with concrete.

Method of blasting concrete

A plurality of moulds each including a side frame and a hollow bed overlying the side frame are vertically stacked with sealing members interposed between the beds and the side frames for hermetically sealing the moulds. While the pressure in the moulds is being reduced a hydraulic substance such as cememt is poured into the moulds. The poured hydraulic substance is heat cured to produce solid articles releasable from the moulds. An empty mould is added to one side of the stack while a mould containing the cured substance is removed from the other side of the stack. Alternatively, the process can be carried out according to a batch system. The moulds may be packed with aggregate, fittings or means for interconnecting the articles.

The weight of aggregate for preparing concrete and mortar is measured while the aggregate is immersed in water contained in a container. The water in the container is discharged and the water in the interstice in the aggregate is also removed. Thereafter the weight of the aggregate is measured again. These measured values of the aggregate are used to determine the quantity of water to be added to the aggregate when it is used to prepare concrete or mortar.

Method and apparatus for weighing aggregates

The fluidity of a plastic fluid, cement mortar for example, is measured by passing the fluid through a flow passage packed with an aggregate for simulating an actual mould, measuring the flow pressure, and measuring the quantitative flow coefficient between the fluid and the flow passage. The pressure remaining in the passage after the fluid has been poured into the passage and after the flow speed has been decreased to zero or the pressure after a quantity of the fluid has been added to the passage and prior to the discharge of the fluid from the passage is measured to determine the relative shear stress yielding value. Thereafter, the fluid is caused to flow to determine again the relative shear stress yielding value, and the relative closure coefficient is determined by the difference between said two relative shear stress yielding values. After the elapse of a predetermined time the plastic fluid is caused to flow under a pressure and the pressure at the commencement of the flow is measured to quantitatively determine the variation in the shear stress yielding value with time, thereby determining the relative initial flow pressure. The relative flow viscosity coefficient is measured by varying the flow speed of the plastic fluid and by determining the relationship between the speed and the pressure of the plastic fluid. In the actual moulding operation the plastic fluid is prepared by using the factors thus determined and the pouring conditions are predetermined, or automatically controlled.

Method and device for measuring the characteristics of plastic fluid and

Hydraulic cement or the like is poured into a closed mould under a reduced pressure condition to a level slightly higher than a predetermined level. Coarse aggregate and steel rods are prepacked in the mould. After pouring, the pressure in the mould is increased to atmospheric pressure or a higher pressure to force the hydraulic cement above the predetermined level back into the space below the level thus compacting the poured in hydraulic cement. A cushion device is provided for the pouring device. An overflow tank is connected to the mould to observe the level of the poured cement. The pressure in the overflow tank is also decreased during pouring and increased after pouring.

Apparatus for moulding hydraulic cement or the like material

Hydraulic cement or the like is poured into a closed mould under a reduced pressure condition to a level slightly higher than a predetermined level. Coarse aggregate and steel rods are prepacked in the mould. After pouring the pressure in the mould is increased to atmospheric pressure or a higher pressure to force the hydraulic cement above the predetermined level back into the space below the level thus compacting the poured in hydraulic cement. A cushion device is provided for the pouring device. An overflow tank is connected to the mould to observe the level of the poured cement. The pressure in the overflow tank is also decreased during pouring and increased after pouring.

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Tokyo, Japan

Hideharu Kaga