Timber-concrete composite connector and ductile reinforcement chair
A timber-concrete composite floor or roof system connector that provides high slip modulus stiffness and resiliency through a combination of mechanical and adhesive connections to a timber substrate, ductile structural behavior under ultimate loading, and an integrated method for chair support of concrete slab reinforcing members during wet concrete placement.
1 . A timber-concrete composite connector comprising:
a steel base plate which is configured to be attached to a timber substrate and which when attached to the timber substrate achieves a rigid connection with the timber substrate, the steel base plate extending along a longitudinal direction; and
a steel top bar unitary with or secured to the steel base plate and which has at least one steel top bar module that is designed to yield under ultimate horizontal shear loads applied in the longitudinal direction and experience linear or effectively linear plastic deformation under the ultimate loads while the steel base plate and timber substrate remain elastic, the steel top bar extending along the longitudinal direction with the at least one steel top bar module located on an effective plane which is perpendicular to a plane of the steel base plate, the at least one steel top bar module (a) having two inclined legs, which are relatively straight segments that are inclined toward each other relative to the longitudinal direction, and (b) having a relatively horizontal segment between the two inclined legs.
2 . The timber-concrete composite connector of claim 1 , wherein the at least one steel top bar module is designed to experience elastic deformation below ultimate loads, yield when subjected to the ultimate loads, and experience constant or effectively constant plastic deformation when subjected to the ultimate loads.
3 . The timber-concrete composite connector of claim 1 , wherein:
the steel top bar and the base plate are a unitary structure; and
the steel top bar and the base plate are pressed, stamped or expanded from a same sheet of steel.
4 . The timber-concrete composite connector of claim 1 , wherein:
the steel top bar and the base plate are a unitary structure; and
the steel top bar and the base plate are cut and bent or cut and folded from a same sheet of steel.
5 . The timber-concrete composite connector of claim 1 , wherein:
the steel top bar comprises a deformed reinforcing bar, steel wire, or steel gage metal; and
the steel top bar is welded to the steel base plate.
6 . The timber-concrete composite connector of claim 1 , wherein the base plate has holes, each with a longitudinal axis that is not orthogonal to an effective plane of the base plate.
7 . The timber-concrete composite connector of claim 1 , wherein the timber-concrete composite connector is configured to accommodate an acoustic material layer between the base plate and the topping slab in which the reinforcing bar is embedded.
8 . The timber-concrete composite connector of claim 1 , wherein the steel base plate is, at least in part, configured to be attached to the timber substrate with mechanical fasteners.
9 . The timber-concrete composite connector of claim 8 , wherein the steel base plate is configured to be attached to the timber substrate with adhesive and the mechanical fasteners.
10 . The timber-concrete composite connector of claim 1 , wherein the horizontal segment of the at least one steel top bar module has a dip defining a chair.
11 . The timber-concrete composite connector of claim 1 , wherein the at least one steel top bar module is formed from and protrudes from the steel base plate.
12 . The timber-concrete composite connector of claim 11 , comprising plural steel top bar modules all of which are arrayed along the longitudinal direction and on the effective plane, the steel base plate configured to be attached to the timber substrate by mechanical fasteners at effective endpoints of adjacent steel top bar modules.
13 . The timber-concrete composite connector of claim 1 , comprising plural steel top bar modules all of which are arrayed along the longitudinal direction and on the effective plane, the steel base plate configured to be attached to the timber substrate by mechanical fasteners at effective endpoints of adjacent steel top bar modules.
14 . The timber-concrete composite connector of claim 1 , wherein the horizontal segment of the at least one steel top bar module has a dip defining a chair that can receive a reinforcement bar extending transverse to the longitudinal direction.
15 . The timber-concrete composite connector of claim 1 , wherein the at least one steel top bar module is continuously curvilinear along the two inclined legs and the horizontal segment.
16 . A timber-concrete composite structure comprising:
a timber-concrete composite connector according to claim 1 ; and
a timber substrate to which the timber-concrete connector is attached,
wherein the timber substrate comprises cross-laminated timber (CLT), glued-laminated timber panels (GLT), nail-laminated timber (NLT), dowel-laminated timber (DLT), laminated veneer lumber (LVL), mass plywood panels (MPP), glued-laminated beams (Glulam), or parallel strand lumber (PSL).
17 . The timber-concrete composite structure of claim 16 , wherein the timber substrate comprises bamboo.
18 . The timber-concrete composite structure of claim 16 , comprising a concrete topping slab in which the timber-concrete composite connector is embedded.
19 . The timber-concrete composite structure of claim 16 , wherein the concrete topping slab comprises gypsum concrete.
20 . The timber-concrete composite structure of claim 16 , comprising, supported by the at least one steel top bar module chair, deformed reinforcing bars, welded wire fabric, post-tensioning cables, carbon fiber rods, glass fiber rods, or basalt rods.
21 . The timber-concrete composite structure of claim 16 , comprising an acoustic layer between the timber substrate and concrete topping slab, the acoustic layer comprising a rubber mat, a fiber mat, or a foam sheet.
22 . The timber-concrete composite structure of claim 16 , wherein the steel base plate is, at least in part, secured to the timber substrate with mechanical fasteners.
23 . The timber-concrete composite structure of claim 22 , wherein the steel base plate is secured to the timber substrate with adhesive and the mechanical fasteners.
24 . A timber-concrete composite connector comprising:
a steel base plate which is configured to be attached to a timber substrate and which when attached to the timber substrate achieves a rigid connection with the timber substrate, the steel base plate extending along a longitudinal direction;
a steel top bar unitary with or secured to the steel base plate and which has at least one steel top bar module that is designed to yield under ultimate horizontal shear loads applied in the longitudinal direction and experience linear or effectively linear plastic deformation under the ultimate loads while the steel base plate and timber substrate remain elastic, the steel top bar extending along the longitudinal direction with the at least one steel top bar module located on an effective plane which is perpendicular to a plane of the steel base plate, the at least one steel top bar module (a) having two inclined legs, which are relatively straight segments that are inclined toward each other relative to the longitudinal direction, and (b) having a relatively horizontal segment between the two inclined legs; and
a chair formed in the steel top bar in the form of a dip in the horizontal segment and that can receive a reinforcement bar extending transverse to the longitudinal direction.
25 . The timber-concrete composite of claim 24 , wherein the at least one steel top bar module is continuously curvilinear along the two inclined legs and the horizontal segment.