A precast concrete beam is provided in construction of a long span bridge structure. The beam is formed of a plurality of aligned modular elements each formed of prestressed UHPC mix as a unitary body. The UHPC mix includes discontinuous fibers distributed randomly throughout a concrete matrix. Each modular element is aligned modular and connected by an epoxy grout to adhering adjacent element joints. Finally, post-tensioning of the entire beam reinforces and affixes the plurality of aligned modular elements into a single long span beam.

A precast concrete beam is provided in construction of a long span bridge structure. The beam is formed of a plurality of aligned modular elements each formed of prestressed UHPC mix as a unitary body. The UHPC mix includes discontinuous fibers distributed randomly throughout a concrete matrix. Each modular element is aligned modular and connected by an epoxy grout to adhering adjacent element joints. Finally, post-tensioning of the entire beam reinforces and affixes the plurality of aligned modular elements into a single long span beam.

A precast concrete beam A beam for use in construction of a long span bridge structure comprising: a reinforcing member having a geometric configuration selected from a group consisting of: a “U” tub beam with composite deck system; a decked I-beam; and an adjacent box beam; said geometric configuration formed of a UHPC mix having: an initial compressive strength, f′.sub.ci=10.0 ksi; a compressive strength at service, f′.sub.c=17.4 ksi; a modulus of elasticity of concrete, E.sub.c=6500 ksi; a residual rupture stress, f.sub.rr=0.75 ksi; and a concrete unit weight, w.sub.c=0.155 kcf; and
said UHPC mix further comprises a plurality of discontinuous fibers distributed randomly throughout a concrete matrix, said plurality of discontinuous fibers formed of a material selected from the group consisting of: steel; polypropylene; nylon; polyvinyl alcohol; polyolefin; polyethylene; polyester; acrylic; aramid; carbon; silica glass; basalt glass; glass fiber-reinforced polymer; and basalt fiber-reinforced polymer.

A precast concrete beam A beam for use in construction of a long span bridge structure comprising: a reinforcing member having a geometric configuration selected from a group consisting of: a “U” tub beam with composite deck system; a decked I-beam; and an adjacent box beam; said geometric configuration formed of a UHPC mix having: an initial compressive strength, f′.sub.ci=10.0 ksi; a compressive strength at service, f′.sub.c=17.4 ksi; a modulus of elasticity of concrete, E.sub.c=6500 ksi; a residual rupture stress, f.sub.rr=0.75 ksi; and a concrete unit weight, w.sub.c=0.155 kcf; and
said UHPC mix further comprises a plurality of discontinuous fibers distributed randomly throughout a concrete matrix, said plurality of discontinuous fibers formed of a material selected from the group consisting of: steel; polypropylene; nylon; polyvinyl alcohol; polyolefin; polyethylene; polyester; acrylic; aramid; carbon; silica glass; basalt glass; glass fiber-reinforced polymer; and basalt fiber-reinforced polymer.

The invention is a system and method for building a polar zonohedron structure from precast cement panels. The building system may include a plurality of panels configured to register with each other. Each panel includes a precast cement base with side walls enclosing a cavity within the precast cement base. The panels include at least one ridge protruding from at least one surface of a side wall of the panel and at least one aperture on at least one surface of a side wall of the panel. Each ridge is preferable configured to interlock with each aperture; in his way, the panels interlock with each other to form the polar zonohedron structure.

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.

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.

An admixture for making a high-strength concrete with any type of water, including potable water, freshwater, saltwater, brackish water, reclaimed water or any other non-potable water. The admixture consists of basalt fibers, graphene nanoplatelets, calcium sulfide, calcium chloride, magnesium oxide and nanoclays. The admixture can be added to the cement to supplement it to increase the overall compressive strength, or the amount of cement used can be reduced by the amount of admixture added to shorten cure times. A concrete mix can also be prepared by replacing the calcium chloride with silica fume, reducing the amount of cement used, and introducing locally sourced aggregates, coarse and fine, to yield Ultra High Performance Concrete. Products made from the concrete incorporating the admixture have increased compression strength, improved cure times, reduced water consumption and corrosion, increased durability and workability, drastically reduced freeze-thaw effects, and superior crack control.

The present disclosure provides a preparation method of an aluminum silicate fiber-reinforced aerogel felt, including the following steps: mixing orthosilicate, ethanol, and water evenly, adding an NH.sub.4F solution and ammonia water successively, and stirring evenly to obtain a silica sol; winding an aluminum silicate fiber felt into a roll and mounting on a rotatable central shaft of a impregnation reaction kettle; where a plurality of injection holes are equidistantly provided on a surface of the reaction kettle; the central shaft of the reaction kettle drives the aluminum silicate fiber felt to rotate and slowly inject the silica sol into the surface of the fiber felt through the injection holes to conduct the impregnation; allowing the fiber felt-gel composite to stand to conduct aging; placing the aged fiber felt-gel composite in absolute ethanol to conduct solvent replacement to remove moisture; and drying to obtain the aluminum silicate fiber-reinforced aerogel felt.