Abstract: The system and method for connecting a square concrete-filled steel tubular column to a reinforced concrete footing includes a short steel pipe partially embedded in the footing, the pipe having a top end having flanges extending radially therefrom, the top end extending into a cavity in the footing having an elliptical top opening and circular base, the flanges extending above the base. An elliptical base plate is welded to the bottom of the tubular steel column, the base plate having a circular opening defined therein and a plurality of spaced flange slots depending therefrom. The bottom end of the column is lowered into the cavity, the elliptical base plate passing through the elliptical opening in the cavity, and the column is rotated 90° to interlock the flanges with the flange slots. The cavity is filled with concrete grout, and the square or rectangular steel column is filled with concrete.

Abstract: The system and method for connecting a square concrete-filled steel tubular column to a reinforced concrete footing includes a short steel pipe partially embedded in the footing, the pipe having a top end having flanges extending radially therefrom, the top end extending into a cavity in the footing having an elliptical top opening and circular base, the flanges extending above the base. An elliptical base plate is welded to the bottom of the tubular steel column, the base plate having a circular opening defined therein and a plurality of spaced flange slots depending therefrom. The bottom end of the column is lowered into the cavity, the elliptical base plate passing through the elliptical opening in the cavity, and the column is rotated 90° to interlock the flanges with the flange slots. The cavity is filled with concrete grout, and the square or rectangular steel column is filled with concrete.

Abstract: The hybrid post-installed anchor for concrete is a structural anchor for installation within a hole formed in concrete. The hybrid post-installed anchor for concrete includes an anchor rod and a plurality of anchor rings mounted on and encircling the anchor rod. Each anchor ring includes a cylindrical ring, having opposed open upper and lower ends, and a plurality of fins secured to an outer surface of the cylindrical ring. Each fin has a fixed edge, which is secured to the outer surface of the cylindrical ring, and a free edge. Each fin projects radially and upwardly, such that each fin is angled with respect to a common central axis of the anchor rod and each anchor ring when the anchor rings are mounted coaxially on the anchor rod. Alternatively, the fins may be formed integrally on the anchor rod, without separate cylindrical rings.

Abstract: The method of connecting a circular concrete-filled steel tubular column to a reinforced concrete footing provides a process for constructing a circular concrete-filled steel tubular column anchored in a reinforced concrete footing. A tubular member is partially embedded in a cavity formed in a block of reinforced concrete, such that a pair of flanges thereof is positioned adjacent to and above a base surface of the cavity. A steel tube is partially inserted into the cavity, such that rotation of the steel tube will cause the pair of flanges to interlock with a pair of slots at the lower end of the steel tube, locking the steel tube in place with respect to the tubular member and the block of reinforced concrete. The cavity is filled with concrete grout to secure the column, and the steel tube is filled with concrete to form the circular concrete-filled steel tubular column.

Abstract: The system and method for connecting a square concrete-filled steel tubular column to a reinforced concrete footing includes a short steel pipe partially embedded in the footing, the pipe having a top end having flanges extending radially therefrom, the top end extending into a cavity in the footing having an elliptical top opening and circular base, the flanges extending above the base. An elliptical base plate is welded to the bottom of the tubular steel column, the base plate having a circular opening defined therein and a plurality of spaced flange slots depending therefrom. The bottom end of the column is lowered into the cavity, the elliptical base plate passing through the elliptical opening in the cavity, and the column is rotated 90° to interlock the flanges with the flange slots. The cavity is filled with concrete grout, and the square or rectangular steel column is filled with concrete.

Abstract: A damped reinforced joint for a beam-column connection is provided for improving the resistance of steel-framed buildings against progressive collapse. Prestressing cables extend across each joint, and each prestressing cable is partially encased within a bent pipe. Each bent pipe may have multiple bends, forming a rippled or undulating shape. The prestressing cables strengthen the connections in the joints, and the bent pipes provide damping for dissipation of seismic energy and the like, thus improving resistance to earthquakes and other seismic, vibratory and/or shock events to the building frame.

Abstract: The fiber elements for soil stabilization include a combination of rigid and flexible fibers that are adapted to be added to soil in order to stabilize the soil to improve the geotechnical characteristics thereof. Each fiber element includes a rigid fiber having opposed first and second ends, at least the first end defining a first ring. A plurality of flexible fibers are attached to the first ring. When mixed with soil, the rigid fibers provide stiffness to the soil mass, and the flexible fibers provide deformability. For purposes of packaging, prior to addition to soil, the plurality of flexible fibers may be at least partially secured to one another by a water soluble material, such as a water soluble glue, water soluble thread or the like. A plurality of the fiber elements may be secured to one another by the water soluble material, forming a fiber module.

Abstract: The reinforced joint for a beam-column connection is provided for improving the resistance of steel-framed buildings against progressive collapse. Flange stiffening plates reinforce flanges of structural beams, with beam web stiffeners being attached to and extending between the flange stiffening plates. Additional column web stiffeners are attached to and extend between flanges of a structural column. A longitudinal cover stiffening plate is attached to the column stiffeners and the flange stiffening plates, extending across the joint and at least partially covering the beam web stiffeners. The reinforced joint between the structural beams and the structural column develops catenary action in the structural beams in the event of collapse.

Abstract: An integral dual module geopolymer building block includes an inner foam module for insulation and an outer dense tile surface on an outer side of the inner foam module for weather protection. The outer porous module comprises a geopolymer paste including sodium silicate and sodium hydroxide flakes dissolved in the sodium silicate to form an activated solution and adding calcined kaolin clay to the activated solution to form a geopolymer paste. A first relatively dense tile layer has a thickness of about 0.5 cm to 1.5 cm. A second geopolymer layer made from a second mass of paste mixed with hydrogen peroxide forms a geopolymer foam having a thickness of between 5 cm and 15 cm.

Abstract: The method of connecting a circular concrete-filled steel tubular column to a reinforced concrete footing provides a process for constructing a circular concrete-filled steel tubular column anchored in a reinforced concrete footing. A tubular member is partially embedded in a cavity formed in a block of reinforced concrete, such that a pair of flanges thereof is positioned adjacent to and above a base surface of the cavity. A steel tube is partially inserted into the cavity, such that rotation of the steel tube will cause the pair of flanges to interlock with a pair of slots at the lower end of the steel tube, locking the steel tube in place with respect to the tubular member and the block of reinforced concrete. The cavity is filled with concrete grout to secure the column, and the steel tube is filled with concrete to form the circular concrete-filled steel tubular column.

Abstract: The multi-leg fiber reinforced concrete is concrete in which fibers have been embedded to prevent the concrete from being fractured due to cracks developing therein. Each fiber has multiple legs, defining two and three dimensional structures. At least one fiber is embedded in a volume of concrete, where the at least one fiber has at least first and second legs respectively extending along first and second directions. The first and second directions are angularly oriented with respect to one another between 45° and 135°, with each of the first and second legs having a free end and a fixed end. Each free end has a substantially Z-shaped contour. The fixed ends of the first and second legs may be joined together to define a two-dimensional fiber structure. The at least one fiber may be partially coated with a polymeric material, such as polypropylene.

Abstract: The multi-leg fiber reinforced concrete is concrete in which fibers have been embedded to prevent the concrete from being fractured due to cracks developing therein. Each fiber has multiple legs, defining two and three dimensional structures. At least one fiber is embedded in a volume of concrete, where the at least one fiber has at least first and second legs respectively extending along first and second directions. The first and second directions are angularly oriented with respect to one another between 45° and 135°, with each of the first and second legs having a free end and a fixed end. Each free end has a substantially Z-shaped contour. The fixed ends of the first and second legs may be joined together to define a two-dimensional fiber structure. The at least one fiber may be partially coated with a polymeric material, such as polypropylene.

Abstract: The multi-leg fiber reinforced concrete is concrete in which fibers have been embedded to prevent the concrete from being fractured due to cracks developing therein. Each fiber has multiple legs, defining two and three dimensional structures. At least one fiber is embedded in a volume of concrete, where the at least one fiber has at least first and second legs respectively extending along first and second directions. The first and second directions are angularly oriented with respect to one another between 45° and 135°, with each of the first and second legs having a free end and a fixed end. Each free end has a substantially Z-shaped contour. The fixed ends of the first and second legs may be joined together to define a two-dimensional fiber structure. The at least one fiber may be partially coated with a polymeric material, such as polypropylene.

Abstract: The method of connecting a circular concrete-filled steel tubular column to a reinforced concrete footing provides a process for constructing a circular concrete-filled steel tubular column anchored in a reinforced concrete footing. A tubular member is partially embedded in a cavity formed in a block of reinforced concrete, such that a pair of flanges thereof is positioned adjacent to and above a base surface of the cavity. A steel tube is partially inserted into the cavity, such that rotation of the steel tube will cause the pair of flanges to interlock with a pair of slots at the lower end of the steel tube, locking the steel tube in place with respect to the tubular member and the block of reinforced concrete. The cavity is filled with concrete grout to secure the column, and the steel tube is filled with concrete to form the circular concrete-filled steel tubular column.

Abstract: The multi-leg fiber reinforced concrete is concrete in which fibers have been embedded to prevent the concrete from being fractured due to cracks developing therein. Each fiber has multiple legs, defining two and three dimensional structures. At least one fiber is embedded in a volume of concrete, where the at least one fiber has at least first and second legs respectively extending along first and second directions. The first and second directions are angularly oriented with respect to one another between 45° and 135°, with each of the first and second legs having a free end and a fixed end. Each free end has a substantially Z-shaped contour. The fixed ends of the first and second legs may be joined together to define a two-dimensional fiber structure. The at least one fiber may be partially coated with a polymeric material, such as polypropylene.

Abstract: The strengthening system for beam-column connections in steel frame buildings to resist progressive collapse helps to mitigate progressive collapse in the event of accidental column loss by using a system of rippled steel plates reinforcing the beam-column connection. Various configurations of rippled steel plates are provided to connect in-plane and transverse beams at a joint. In the event of severe damage caused to a column of a steel framed building, the upper joints of the damaged column undergo downward movement. The rippled plates at the joint straighten during the initial downward movement, and resist further downward movement after complete straightening of the ripples. This helps in the development of catenary action in steel beams. The proposed system is simple, fast to construct, demountable, and easy to repair/replace after damage caused by blast loads.

Abstract: An interlocking and insulated construction block includes a first pair of parallel, opposing sides and a second pair of parallel, opposing sides extending normal to the first pair of opposing sides. At least one cavity or recess extends through the construction block and includes a first volume of thermal insulation material. One or both sides of the first pair of opposing sides includes a pair of staggered engaging members or a pair of staggered receiving members configured to engage or lock with a mating pair of engaging members or receiving members of another insulated construction block. A plurality of different embodiments of the interlocking and insulated construction blocks may be provided in a set, and provide for mortar-less construction of walls due to their interlocking nature.

Abstract: The precast reinforced concrete construction elements with pre-stressing connectors provide beam-column connections which are post-tensioned through a combination of active and passive pre-stressing tendons. The active pre-stressing tendons improve the efficiency and effectiveness of the beam-column connections under service loads, as well as during application of external forces and stresses, such as during earthquakes. The passive pre-stressing tendons are lightly pre-stressed and only become effective during progressive collapse of the building. Specifically, the passive pre-stressing tendons become stressed only during downward movement of a joint due to the loss/damage of a column, thus providing resistance against further downward movement of the joint and thereby resisting the progressive collapse.

Abstract: A concrete-filled steel tubular column for high load capacity, usually required in tall buildings, includes an outer longitudinally extending generally vertical tubular shell and an inner longitudinally extending perforated tubular steel shell disposed within said outer longitudinally extending vertical tubular shell and coaxial therewith. Further, a plurality of relatively small diameter vertically extending perforated tubular steel members are disposed around said inner longitudinally extending tubular shell between said outer longitudinally extending tubular steel shell and said inner longitudinally extending steel shell with axes parallel to said coaxial axes. The concrete-filled steel column wherein said inner steel shell is centrally disposed within the outer longitudinally extending vertical tubular steel shell and wherein the volume between the outer steel shell and the inner shell is filled with high strength concrete.

Abstract: An interlocking masonry block system for the construction of load bearing and non-load bearing walls includes a plurality of generally rectangular shaped building blocks wherein each block comprises a pair of opposite longitudinally extending sidewalls each of which includes an interior rectangular shaped vertical rib. The block also includes a central section disposed between the sidewalls in an abutting relationship therewith. Further, the central section defines one or two diagonally oriented rectangular vertical passageway extending through the central section at an angle of between about 30° and 45° and preferably at an angle of about 38°. The central section also includes one to three vertical extending recesses corresponding to and mating with the vertical ribs on each side thereof. The central section and the pair of sidewalls also define up to four rectangular shaped vertical passageways for utility pipes and/or electrical conduits.