The present invention provides a fiber-reinforced cement composition comprising; cement, fiber, silica, filler, expanded perlite, and polymer. The fiber-reinforced cement composition according to the present invention has low density, high toughness and flexural strength, and not contains volatile composition. When it is molded into workpiece, the workpiece is lightweight, easy to be cut and/or lathed into desired shapes, drilled and fixed with screws and/or repeatedly nailed at the same position, tolerant to humidity, termites and insects, inflammable and does not produce powder when cut, drilled and/or lathed that is hazardous to the workers. Therefore, it is suitably applicable for being utilized as a material for manufacturing furniture parts.

The invention relates to a construction panel with high resistance to fire and to a method for producing a construction panel with high resistance to fire.

The invention relates to a construction panel with high resistance to fire and to a method for producing a construction panel with high resistance to fire.

PROBLEM TO BE SOLVED: To provide a concrete structure and a concrete slab, which, by using a continuous fiber-reinforced polymer material as a main reinforcing material or a tendon, and by mixing a short fiber reinforcing material in concrete, compensate for the mechanical shortcomings of the continuous fiber-reinforced polymer material, not rusting, and taking advantage of superior characteristics of the continuous fiber-reinforced polymer material, with low manufacturing cost and ultra-high durability.

MEANS TO SOLVE THE PROBLEM: In a concrete structure, in which a continuous fiber-reinforced polymer material is arranged as a main reinforcing material or a tendon, a short fiber reinforcing material consisting of an organic fiber is mixed in 0.5% or more with respect to an entire volume, the continuous fiber-reinforced polymer material is shaped like a rod or a stranded wire, a ratio Lf/Gm between a fiber length Lf of the organic fiber of the short fiber reinforcing material and a maximum aggregate diameter Gm of a concrete composition is 1.2 to 3.7, and an aspect ratio Lf/De when an equivalent diameter De, which is a cross-sectional area of the organic fiber converted into a circle diameter, is 30 to 69.

A reinforcing bar comprising a core is provided. The core comprises ultra-high-molecular-weight polyethylene fibers aligned in an axial direction and a polyethylene matrix. The ultra-high-molecular-weight polyethylene fibers are bound in the polyethylene matrix. A shell comprising ultra-high-molecular-weight polyethylene tape surrounds the core in a radial dimension.

A concrete composition having an optimized formulation and suitable for 3-D printing is provided. The composition may include a hydraulic cement composition, aggregate, cement and/or aggregate by-product dust, one or more rheology modifiers, a plasticizer, fibers, and a sufficient amount of water to effect setting of the composition. Optionally the concrete composition may include a setting agent. A method for 3D printing multiple layers of the concrete composition is also provided.

The present disclosure relates to a “concrete slotted floor” manufactured from an UHPC composition which exhibits superior crack resistance due to uniform distribution of reinforcing fibers even when a residing surface is located below, allows early demolding due to fast initial setting time and exhibits improved cleaning efficiency due to maximized surface water repellency, an “UHPC composition for manufacturing the same” and a “method for manufacturing a concrete slotted floor using the same”.

A structural barrier and energy absorbing device comprises a plurality of structural elements. The structural element alone or in a plurality may serve as a traversal impediment or energy absorbing device, such as a pedestrian barrier, vehicular barrier, anti-tank obstacle, ballistic barrier, or the like. The structural element may be a tetrapod such that it comprises an element body having four extension portions that extend outwardly from the interior center to a distal end, such that the structural element maintains an identical orientation and a low center of gravity in each of four resting positions. The structural element may be a solid-state structural element comprised of a particular material or a portable and collapsible structural element wherein the element body comprises an outer skin defining an interior void space, such that during set-up or installation the interior void space may be filled with a filler substance onsite.

The present invention provides a crack repair material of a concrete vacuum tube segment using ultra-high performance concrete (UHPC) for a hyper-speed transportation system and a crack repairing method for the same capable of, in a case in which a vacuum tube segment of a hyper-speed transportation system, such as the Hyperloop, is manufactured using UHPC, repairing cracks formed in the UHPC vacuum tube segment easily and conveniently using a crack growth prevention material and a patch repair material and capable of immediately repairing cracks formed in the UHPC vacuum tube segment to secure airtightness so that operation of a vacuum pump is minimized and overload of the vacuum pump is prevented.

The present invention provides a concrete vacuum tube segment for a hyper-speed transportation system using ultra-high performance concrete (UHPC) and a manufacturing method thereof. A concrete vacuum tube segment for a hyper-speed transportation system can be easily manufactured using UHPC, in which shrinkage and structural cracking do not occur due to mixing a binder and a short fiber to secure airtightness on the basis of a maximum fill theory, and accordingly, shrinkage of the concrete vacuum tube segment can be reduced even in a partial-vacuum state in which the magnitude of drying shrinkage is very small and quick drying occurs; when mixing the UHPC, an antifoaming agent is mixed and a circular vacuum pump is used to remove generated entrapped air to minimize the entrapped air; and a capsule-type crack healing material, which is able to repair fine cracks, is compacted to secure airtightness of the concrete vacuum tube segment.