An axial compression steel tubular column with internal local restraint and filled with high strengthen compound concrete containing normal-strength demolished concrete lumps and a construction process. The axial compression column includes a steel tube (1), high-strength fresh concrete (2), normal-strength demolished concrete lumps (3), a spiral stirrup (4), and longitudinal erection bars (6). The spiral stirrup (4) is arranged at a middle part inside the steel tube (1). The high-strength fresh concrete (2) is poured and the normal-strength demolished concrete lumps (3) are put alternately inside the steel tube (1). A compressive strength of the high-strength fresh concrete (2) is 30˜90 MPa greater than that of the normal-strength demolished concrete lumps (3).

A seismic steel tubular column with internal local restraint and filled with high strengthen compound concrete containing normal-strength demolished concrete lumps, and a construction process. The seismic column includes a steel tube (1), high-strength fresh concrete (2), normal-strength demolished concrete lumps (3), horizontal stirrups (4), and longitudinal erection bars (5). The horizontal stirrups (4) are arranged at upper and lower ends inside the steel tube (1). The high-strength fresh concrete (2) is poured and the normal-strength demolished concrete lumps (3) are put alternately inside the steel tube (1). A compressive strength of the high-strength fresh concrete (2) is 30˜90 MPa greater than that of the normal-strength demolished concrete lumps (3).

A permanent form (13) serving to form concrete structures and comprising sidewalls (11) comprises: an interior form (14) that forms the inner face of a side wall; an exterior form (16) that forms the outer face of the sidewall; and a plurality of vertical reinforcements (17) that are disposed between the interior form and the exterior form and that hold the exterior form alone or together with the interior form. The exterior form and the interior form have: a plurality of base plates (18) that are formed from plastic into square plates and that are aligned so as to be in firm contact with each other in the vertical and horizontal directions; a plurality of central reinforcement plates (19) that are formed from plastic into square plates substantially equal in size to the base plates, that join four adjacent base plates, and that are aligned so as to be in firm contact with each other in the vertical and horizontal directions; and a plurality of end reinforcement plates (21) that are formed from plastic into rectangular plates are arranged into a quadrangular frame so as to join adjacent base plates while being located on the outer edges of the plurality of central reinforcement plates aligned so as to be in firm contact with each other in the vertical and horizontal directions.

A stringer and plank pallet, system and method includes a plurality of planks made of a composite material or a non-wood material and a thickness and holes defined therein comprising a plurality of post cutouts in each of a first and a second end of the plurality of planks. A plurality of stringers made of the composite or non-wood material are configured to receive the plurality of planks via a plurality of post plugs equivalent to the plank thickness and complementary to the plurality of post cutouts. An assembled outside surface relation of the plurality of stringers to the plurality of planks is self-aligning and flush. A plurality of holes are defined in the planks adjacent a first and a second end of the post cutouts to receive a plurality of fasteners driven into the plurality of stringers.

What is presented is a unit cell comprising a cellular geometry that comprises cell walls and cell edges arranged into a combination of a cubic cell geometry and a tetrahedral cell geometry arranged to have a coincident central vertex. The cubic cell geometry comprises three orthogonal cell faces that intersect at its central vertex. The tetrahedral cell geometry comprises an arrangement of eight tetrahedral cells that share its central vertex such that each tetrahedral cell shares three coincident edges with three other tetrahedral cells in a cubically symmetric arrangement. The tetrahedral cell geometry is combined with the cubic cell geometry such that all vertices of the tetrahedral cell geometry are coincident with the vertices of the cubic cell geometry.

A multi-layered inflammable wood material A for use as a building material includes a support wood material part 1 for supporting load, an inner inflammable wood material part 2a attached to a periphery of the support wood material part 1, and an outer inflammable wood material part 2b attached to a periphery of the inner inflammable wood material part 2a, wherein the inner inflammable wood material part 2a and the outer inflammable wood material part 2b both contain therein an inflammable agent, and an amount of the inflammable agent contained in the inner inflammable wood material part 2a is smaller than an amount of the inflammable agent contained in the outer inflammable wood material part 2b.

A multi-layered inflammable wood material A for use as a building material includes a support wood material part 1 for supporting load, an inner inflammable wood material part 2a attached to a periphery of the support wood material part 1, and an outer inflammable wood material part 2b attached to a periphery of the inner inflammable wood material part 2a, wherein the inner inflammable wood material part 2a and the outer inflammable wood material part 2b both contain therein an inflammable agent, and an amount of the inflammable agent contained in the inner inflammable wood material part 2a is smaller than an amount of the inflammable agent contained in the outer inflammable wood material part 2b.

The technology provides increased capability and control over the yield performance of the timber prop, a mine roof support. The new Wedge Prop design includes a cut pattern idealized for the specific wood species used in manufacturing and a set of confinement rings varying in strength due to different failure mechanisms. The cut pattern is based on the diameter of the yellow poplar pole, while the confinement rings consist of multiple types of welds to allow for either wire tensile failure or for weld detachment. The cut pattern can be combined in conjunction with various combinations of confinement rings to allow for precise control over the performance of the Wedge Prop in the Propsetter System.

The technology provides increased capability and control over the yield performance of the timber prop, a mine roof support. The new Wedge Prop design includes a cut pattern idealized for the specific wood species used in manufacturing and a set of confinement rings varying in strength due to different failure mechanisms. The cut pattern is based on the diameter of the yellow poplar pole, while the confinement rings consist of multiple types of welds to allow for either wire tensile failure or for weld detachment. The cut pattern can be combined in conjunction with various combinations of confinement rings to allow for precise control over the performance of the Wedge Prop in the Propsetter System.

A three-dimensional load bearing structure may include a plurality of load bearing members, or force members, that are joined at a plurality of nodes to define a load bearing structure. The structure may include a plurality of longitudinal members extending in parallel along a longitudinal length of the truss structure, and a plurality of transverse members, joined to the plurality of longitudinal members at nodes, and extending between the plurality of longitudinal members. The plurality of transverse members may provide buckling support to the plurality of longitudinal members, so that an axial load, or compressive load, or buckling load, may be effectively carried by the truss structure.