An impact-absorbing assembly includes a covering layer being one or more of artificial turf, rubber mats, polymer mats, short pile carpeting, particulate infill, wood chips, and ground rubber chips. Also included is a layer of underlayment panels positioned beneath the covering layer. The panels have a panel section with a plurality of drain holes formed therethrough. A top surface of the panels is configured to support the covering layer. A bottom surface of the panels has a plurality of bottom projections that cooperate to define bottom channels suitable to permit water flow across the bottom surface, the bottom channels being in fluid communication with the panel drain holes. The bottom projections define a first spring rate characteristic that is part of a first stage and a second spring rate characteristic is part of a second stage, the first stage having a smaller volume of material than the second stage.

A playing surface comprising a supportive base layer, an intermediate layer such as a foam layer, and a surface layer, wherein the base layer is configured to provide the playing surface with a first predetermined amount of stability and the intermediate layer, e.g. foam layer, is configured to provide the playing surface with an additional, second predetermined amount of stability, the intermediate layer, e.g. foam layer, being further configured to conform to a required performance standard. And a method of constructing a playing surface.

A heatable module for use in constructing a pathway for traffic comprises a base member having a perimeter edge. A top plate is securable to the base member in overlying relation to the top surface of the base member. An electrically powerable heater member retained by at least one of the base member and the top plate. To form a heatable pathway for traffic, the modules are placed in perimeter-edge-to-perimeter-edge relation one to the next.

A heatable pathway system for traffic comprises a first module having a first electrically powerable heater member and a second module having a second electrically powerable heater member. The first module and the second module are each installable in place to form a heatable pathway system for traffic. An electrical power controller circuit has a first power output connected in power supplying relation to the first electrically powered heater member and a second power output connected in power supplying relation to the second electrically powerable heater member. The electrical power controller circuit is operable to provide electrical power from the power outputs in a heating cycle that comprises a first heating sub-cycle and a second heating sub-cycle such that, during a heating cycle, a first one of the electrically powerable heater members is on and a second one of the electrically powerable heater members is off during the first heating sub-cycle, and the second electrically powerable heater member is on and the first electrically powerable heater members is off during the second heating sub-cycle.

A paving system for paving or flooring includes a top layer of a plurality of paving elements, and an underlayment support layer of a polymeric material configured into panels. The panels are suitable to support the paving elements, the panels having a generally planar support surface.

A lightweight universal panel mat made of plastic or elastomeric material and having a first section that provides a relatively flat, textured or structured top surface to facilitate movement over the upper surface and a second section having geometry that includes a plurality of cells having top surfaces that support the first section. The panel mats also have first, second, third and fourth sides that are configured with tabular extensions or openings, slots or recesses configured and dimensioned to be able to receive the tabular extensions. At least some of the tabs and slots are configured to facilitate snap-locking. Thus, a plurality of similarly configured panel mats can be connected by interlocking of the tabs of one mat into the openings, slots or recesses of one or more adjacent similarly configured mats.

A dual-unit paving system for covering a surface is provided. The system comprises pairs of first and second units. For each pair, the first and second unit have different respective shapes and sizes, and are configured to be matingly engageable for forming a hexagonal assembly having six, non-linear sides. The hexagonal assembly allows forming rotational tessellations. The first and second units are also shaped and configured to be matingly engageable so as to form horizontally aligned tessellations, and also vertically aligned tessellations.

A paving system for paving or flooring includes a top layer of a plurality of paving elements, and an underlayment support layer of a polymeric material configured into panels. The panels are suitable to support the paving elements, the panels having a generally planar support surface.

Dual-unit paving systems for covering a surface. The system includes pairs of first and second units. For each pair, the first and second unit have different respective shapes and sizes, and are matingly engageable for forming a hexagonal assembly having six, non-linear sides. The hexagonal assembly includes forming rotational tessellations. The first and second units are also shaped and matingly engageable so as to form horizontally aligned tessellations, as well as vertically aligned tessellations.

A connection surface disposed on a face of a structural unit comprises a first segment having a three dimensional surface profile including a plurality of positive outer surfaces extending outwardly along a normal direction from a plane and a plurality of negative outer surfaces extending inwardly along the normal direction from the plane, wherein at least two of the plurality of positive outer surfaces are separated from one another along both vertical and horizontal directions and at least two of the plurality of negative outer surfaces are separated from one another along vertical and horizontal directions. A second segment opposes the first segment with respect to an axis, wherein the second segment is a substantial reflection of the first segment across the axis, but reversed along the normal direction.