Described herein is a building panel and related building systems, the building panel having a first major surface opposite a second major surface, the building panel comprising a core comprising a first body comprising a first fibrous material; and a second body comprising a second fibrous material, a veneer facing layer coupled to the core, the veneer facing layer comprising a plurality of perforations.

An acoustic absorber includes a chamber formed from walls with a resistive portion providing the only communication between the chamber volume and ambient air. In some examples chamber walls enable selection or adjustment of chamber volume or resistive area, thereby altering the acoustic absorption spectrum below 250 Hz. In some examples the chamber volume contains fibrous filler material exhibiting no airflow resistance or acoustic absorption. Density and heat capacity of the fibrous filler material results in the chamber volume exhibiting compressibility of air within the chamber, for at least acoustic frequencies up to about 50 Hz, that is larger than adiabatic compressibility of air. That larger compressibility results in an increased acoustic absorption coefficient, for at least acoustic frequencies up to about 50 Hz, 50% to 100% larger than that of an identical chamber entirely characterized by the adiabatic compressibility of air.

A variable acoustic system for selectively controlling acoustic properties of an environment. Said variable acoustic system comprises a two side portions, a back portions and a variable expansion assembly. Said variable acoustic system further comprises a shell and a plurality of absorbers. Said variable acoustic system is configured to selectively transition through a one or more configurations. Said one or more configurations comprises at least a closed configuration and an open configuration. Said closed configuration comprises said two side portions closed with said shell exposed. Said open configuration comprises said two side portions open with a portion of said plurality of absorbers exposed. Said shell configured to reflect more acoustic energy than said plurality of absorbers. Said two side portions comprise a first side portion and a second side portion. Said two side portions each comprise at least an outer portions and a back absorbers.

A building element includes a sheet of a rigid material and at least one nonlinear energy sink including a blade with two end parts and a nonlinear spring function intermediate part, a mass fixed to the nonlinear spring function intermediate part of the blade, and a fixing element allowing the two end parts of the blade to be fixed to a solid support in such a way that the nonlinear spring function intermediate part can oscillate about its position of equilibrium or its positions of equilibrium. The nonlinear energy sink is fixed rigidly to the sheet by the fixing element. The building element can be contained in a partition wall. Additionally, such an energy sink or building element can be used for reducing the acoustic transparency of a wall.

The present invention relates to a concrete structure for constructing a building floor and a building floor construction structure including the same. The present invention provides a concrete structure for constructing a building floor which forms a building floor foundation, including: a concrete main body to store fire-extinguishing water for fire suppression; and a fire-extinguishing water injection unit to inject the fire-extinguishing water stored in the concrete main body, and a building floor construction structure including the same. According to the present invention, the concrete structure for forming a building floor stores fire-extinguishing water, and thus early fire suppression is possible, building floor construction is facilitated, and excellent inter-floor sound insulation properties are provided.

An acoustic panel is provided that includes a first skin, a second skin and a core structure. The core structure is connected to and forms a plurality of cavities between the first skin and the second skin. The cavities include a first cavity and a second cavity. The first cavity is fluidly coupled with one or more first perforations in the first skin. The second cavity is fluidly coupled with one or more second perforations in the second skin.

Two or more soundproof cells arranged in a two-dimensional manner are provided. At least one of the soundproof cells is a first soundproof cell configured to include a first frame having a first through-hole. At least one of the other soundproof cells is a second soundproof cell including a second frame having a second through-hole and a film fixed to the second frame. A first shielding peak frequency, which is determined by the first through-hole of the first soundproof cell and at which a transmission loss is maximized, is present on a lower frequency side than a first natural vibration frequency of the film of the second soundproof cell, and sound in a predetermined frequency band centered on the first shielding peak frequency is selectively insulated.

A sound control firestop device. It has a horizontal pad portion made from an elastomeric or fibrous material with a first surface and a second surface opposite the first surface, the horizontal pad portion having a length and a width; and a vertical projection spacer portion projecting outwardly from the second surface, wherein the vertical projection portion extends across at least a portion of the width of the horizontal pad portion. A method of installation thereof.

An exemplary inventive acoustic wall panel includes a pair of congruent flat rectangular plates and a housing. The two plates adjoin at their respective vertical edges to form an angle between the two plates, wherein 90<180. Each plate has a material characteristic relating to acoustic reduction through the plate. Design of an inventive wall panel includes selection of the angle and the respective plate materials, with an objective of producing counteractive acoustic vibratory motions in the two plates in response to sound waves impinging upon the inventive wall panel. Acoustic vibratory motion is induced in each plate whereby the respective vibratory motions tend to oppose each other, thereby reducing sound transmission across the inventive wall panel. The housing lends support to the two attached plates and facilitates connection of the inventive wall panel to another inventive wall panel or to a different structure.

A method of erecting an acoustic shell for stage performances, the shell have frame defining a concave volume that is curved in two orthogonal planes and has an inner surface facing forwardly of a stage for a performance. A plurality of polygonal acoustic panels are positioned in the frame and spaced in rows and column along the inner surface, each panel having an outer acoustically active surface. The frame is formed of plural curved trusses each with a base for support on the stage and a peak. An oculus ring is connected to the peak of each arch and the bases of the arches are space along a bottom curve of the concave volume. The panels comprise plural adjacent blocks in rows and columns, each with a base and inner closed end, the length of each block being different for adjacent blocks.