The invention discloses a method and a system for predicting the corrosion fatigue life of prestressed concrete bridges. A corrosion level of the strand is predicted to obtain the residual tension force of a structure. A stress concentration factor is integrated to consider the stress concentration effect caused by pitting corrosion, and a growth model of the elastic stress of the strand under the coupled effect of corrosion and fatigue is proposed. A growth model of the plastic stress of the strand is established using a cross-section loss of the strand as a fatigue damage parameter based on a degenerated elastic modulus of the concrete after fatigue. Failure criteria for the concrete, the strand, and a longitudinal tension bar are defined, so that a set of methods for analyzing the life of a prestressed concrete bridge subjected to corrosive environment and fatigue load are formed.

Bridge systems and methods for constructing bridges having overhang surfaces employing generally rectangular, precast, prestressed concrete panels. One method includes delivering a plurality of generally rectangular, precast, prestressed concrete panels to an installation site, and delivering one or more support beams to the installation site, each support beam having a support and a base. The concrete panels are positioned on the supports of the one or more support beams with an overhang panel section and a traffic panel section. The concrete panels are then connected to the support beams by positioning steel reinforcement in block outs or voids, pouring unsolidified concrete into the voids, and curing the unsolidified concrete to form an overhang traffic surface. Bridges constructed employing the precast, prestressed concrete panels and methods. Other bridge systems employ prestressed concrete L-walls and double-T members, where weight-bearing L-walls have pockets for webs of the double-T members.

The present invention relates to a cable using cold-drawn shape memory alloy wires, which facilitates concrete prestressing or other operations, and has excellent adhesion to concrete and manufacturability. The cable using cold-drawn shape memory alloy wires includes: a core wire configured by a cold-drawn shape memory alloy deformed by cold drawing to have an increased length; and a plurality of peripheral wires configured by cold-drawn shape memory alloy wires which are deformed by cold drawing to have an increased length and are couple to the core wire while being wound in a same direction along the circumference of the core wire.

The present application disclosures a double production line and a rapid prefabrication process of a segmental beam. The double production line including two production machine and a track system provided on the construction ground; the production machine includes a fixed end mold, two side molds, a bottom mold trolley, a middle internal mold trolley and two side internal mold trolley; two side molds are positioned on two sides of the fixed end mold respectively, the fixed end mold and two side molds together define a pouring position with an end opening, two openings of the pouring position are arranged facing each other; the track system includes a transverse track and a longitudinal track communicated with each other, two pouring positions are both positioned in the extension path of the transverse track, and the longitudinal track is positioned between two pouring positions.

A method for forming a hollow box-shaped cross section beam utilizes double walled trough that allows for prefabrication with pre-stressed concrete. The hollow box-shaped cross section precast beam is formed by filling the fabrication conduit with precast concrete. A number of tendons may be positioned within the fabrication conduit in quantities and positioned that are favorable to resist deflecting forces and provide anchoring forces within the hollow trough or box-shaped cross section precast beam formed therein. Further, a box shaped cross section bridge girder can be formed having no tensile stresses due to its own weight. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

A bridge system is provided that utilizes foundation structures that are formed of the combination of precast and cast-in-place concrete. A method of constructing the combination precast and cast-in-place concrete foundation structures involves receiving at a construction site a precast concrete foundation unit having elongated upright wall members that define a channel therebetween, and multiple upright supports located within the channel; placing the precast concrete foundation unit at a desired use location; delivering concrete into the channel while the precast concrete foundation unit remains at the desired use location; and allowing the concrete to cure-in-place such that the elongated upright wall members are connected to the cured-in-place concrete by reinforcement embedded within both the cured-in-place concrete and the upright wall members. The bridge units may be placed before the pouring step to embed the bottoms of the bridge units in the cast-in-place concrete.

A modular slab, slab system, piles and methods of use thereof are described along with specific applications and methods of manufacture. The slab or slab system may be pre-insulated and pre-finished before being assembled on site. The slab system may be advantageous to use as a replacement for traditional in-situ poured building foundations. The slab system may also have uses in other fields such as for floors, roads, bridges, pavements/side walks and other civil and structural applications.

A precast concrete structure formed of a cementitious mixture is provided, the cementitious mixture comprising a mixture of: (a) cement, (b) silica fume, (c) supplemental material (limestone and/or slag), (d) masonry sand, (e) water and ice (f) plasticizers and (g) workability admixtures. The result is an improved concrete for use in the formation of long span bridge elements that are simple and safe to manufacture and having improved properties. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

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.