摘要:
PROBLEM TO BE SOLVED: To provide a concrete material in which while a unit water content and a used amount of a chemical admixture that are approximately equal to those in a case in which only cement is used are secured, lowering of slump by a lapse time from milling finish can be made small.SOLUTION: The concrete material is a concrete material that is produced such that a mixed cement including at least 70 mass% of an admixture, an aggregate, water, and a chemical admixture are mixed. The blending of the concrete material is made by addition amounts of a prescribed water cement ratio, a unit water content, a fine aggregate ratio and a chemical admixture that are necessary in a case in which only a cement is used to produce a concrete material, however, a chemical admixture that includes a constant amount of a thickener is used as the chemical admixture.
摘要:
PROBLEM TO BE SOLVED: To measure space dose rates at a plurality of measurement points efficiently in a short time without any preparatory work such as marking in advance based upon a survey.SOLUTION: A space dose rate measuring apparatus 20 includes a measurement pole 21, a space dose rate measuring instrument 24 fitted to the measurement pole 21, an antenna 22 and a receiver 23, and a navigation device 25. A computer 25a of the navigation device 25 functions: to perform positioning by analyzing a signal after signal processing by the receiver 23; to make a display device 25c display a position obtained by the positioning together with a plan; to make the space dose rate measuring instrument 24 measure a space dose rate by remotely operating the space dose rate measuring instrument 24 when an indication to start measurement is input through an input device 25b; and to record the position obtained by the positioning in a storage part 25f when the indication to start the measurement is input through the input device 25b.
摘要:
PROBLEM TO BE SOLVED: To provide a shear reinforcement with high workability, in which a fixation portion with a large sectional shape can be provided in an end portion of a screw-knotted irregular-shape steel bar easily, at low costs and stably, and fixation strength of the shear reinforcement and shear strength of a concrete skeleton can be improved.SOLUTION: A shear reinforcement 1 is inserted into a slot 12 formed from a reinforcing surface 11 of a concrete skeleton 10, and embedded with fillings 13 with which the slot 12 is filled. The shear reinforcement 1 comprises: a screw-knotted irregular-shape steel bar 2 with which smooth surfaces 22 extending over a full length are formed at both sides; nuts 3 which are threaded to end portions of the screw-knotted irregular-shape steel bar 2; and protrusions 42, 42 protruding from both sides of a substrate 41 substantially at right angle. The protrusions 42, 42 at both sides are inserted into screw holes 31 of the nuts 3, engaged and disposed along the smooth surfaces 22, 22 at both the sides of the screw-knotted irregular-shaped steel bar 2.
摘要:
PROBLEM TO BE SOLVED: To provide a silencer, a silencing system and a method, which enable an effective reduction in noises generated by blasting, depending on situations of an excavation site.SOLUTION: The present invention provides a silencer, a silencing system and a method for reducing noises generated by blasting. The silencer of the present invention, which assumes a hollow box shape, has one surface of the box shape provided with an opening into which a cylindrical member can be inserted. The silencer can comprise two box bodies that are slidably fitted, and the cylindrical member is installed in the state of protruding to the inside and outside of the box shape.
摘要:
PROBLEM TO BE SOLVED: To surely perform the expansion and contraction of a hole in spite of being low cost.SOLUTION: An excavating tool 1 includes an excavating tool body 10 and a pair of movable blade parts 20, 20 swingably mounted to the tip side of the excavating tool body 10. The movable blade part 20 is swingable around a hole penetrated with a shaft part 13 and in a plane along a plane part. As a result, when the excavating tool 1 is rotated, first, the movable blade part 20 is shaken out by an inertia force and a centrifugal force, and the movable blade part 20 is further projected to the outer peripheral side by friction generated between a gauge tip 3A of its tip and the inner peripheral surface of a lower hole to be placed in an expanded diameter state.
摘要:
PROBLEM TO BE SOLVED: To provide a method and system for allowing the evaluation of almost substantial hole drilling energy to predict a bedrock property with high accuracy.SOLUTION: The method includes using a rock drill for drilling a bedrock, using a measuring device for measuring the hydraulic pressure of the rock drill during drilling the bedrock, using an information processing unit for computing energy required for the rock drill to drill the bedrock from hydraulic pressure data in response to the input of the hydraulic pressure data of the measured hydraulic pressure, and dividing the energy by a drilled volume to calculate drilled volume specific energy. A plurality of bedrock strength data accumulated in a data storage part by the information processing unit and a plurality of dimensionless drilled volume specific energy data obtained by dividing the drilled volume specific energy by bedrock strength are used to create a graph or regression expression representing a relationship between the dimensionless drilled volume specific energy and the bedrock strength. The calculated drilled volume specific energy and the created graph or regression expression are used to predict the bedrock strength of the bedrock.
摘要:
PROBLEM TO BE SOLVED: To provide a drilling apparatus in which a cutter head has a large aperture and even if a drilling target is a hard rock mass or the like, it can be drilled efficiently.SOLUTION: A drilling apparatus comprises an outer circumferential cutter head 20 which is rotated while being pressed to a drilling target and has a circular opening, and a small diameter cutter head 23 which is provided within the opening and can be rotated separately from the outer circumferential cutter head 20. Rotation centers of the outer circumferential cutter head 20 and the small diameter cutter head 23 are deviated and that deviation is made smaller than a rotation radius of the small diameter cutter head 23.
摘要:
PROBLEM TO BE SOLVED: To provide a composite segment for use in constructing a shield tunnel, which allows the emission of carbon dioxide to be reduced during manufacturing, having sufficient durability.SOLUTION: A composite segment comprises a hollow formwork 10 with an arcuate curvature formed from a plate-shaped object which contains iron, and a geopolymer composition 11 made from a silicon-containing filler and an alkali activator as raw materials. The geopolymer composition 11 is poured into the formwork 10, so that, by vapor curing or the like, the silicon contained in the geopolymer composition 11 and the iron contained in the formwork 10 make a chemical bond for fastening of the formwork 10 to the geopolymer composition 11, resulting in the formation of the composite segment.