A power unit is configured for use as part of a concrete screed and includes a frame and a powered drive. The frame includes a drive housing. The powered drive is operably supported by the drive housing and is configured to rotate a rotatable concrete forming drum. The powered drive includes an electric motor and a battery operably coupled to the electric motor and configured to power the electric motor. The powered drive includes a drive shaft drivingly connectable relative to the drum, with rotation of the drive shaft causing corresponding rotation of the drum.

A vibrating float including an elongate plate, having a substantially planar lower surface configured to be moved across the concrete; a plurality of evenly spaced electric motors coupled to the elongate plate and configured to vibrate the plate; and a handle, coupled to the elongate plate, for use by an operator to control movement of the vibrating float.

Powered concrete finishing apparatus including a working head for working the concrete. The working head has a rotatable working surface having a ring shape in contact with the concrete during a finishing operation. The concrete finishing apparatus further includes a motor for driving the working head to perform a rotational working movement on the concrete during the finishing operation. The working surface comprises a clearance for allowing concrete to aggregate within said clearance. The clearance is free of additional working surfaces contacting the concrete during the finishing operation, such as blades, pans, floats or arms, thereby providing an improved finishing of the concrete.

A decorative concrete with a very uniform finish surface and a method of fabricating the same is disclosed. A concrete mixture is poured over a subgrade which defines an exposed surface. The exposed surface is finished with any of several techniques, and the surface is then worked with an abrasive material, and additional techniques are used to color and seal the concrete.

Systems and methods for treating concrete, which includes the steps of wetting a surface of concrete with colloidal silica, allowing time for the colloidal silica to penetrate the concrete surface, and cutting the surface of the concrete with a bladed or segmented tool wherein the longitudinal blade or edge portion is positioned approximately at an angle between 30 degrees and 90 degrees relative to the surface of the concrete.

A tool driver for a power trowel, the tool driver comprising a combination of a magnetic fastening arrangement and a hook and loop based fastening arrangement for releasably holding an abrasive tool to the tool driver, wherein the magnetic fastening arrangement is configured symmetrically around a rotational center of the tool driver, wherein the hook and loop based fastening arrangement is adapted to provide increased shear strength during abrasive operation of the tool, and wherein the magnetic fastening arrangement is adapted to provide increased pull strength during lifting of the tool driver.

Grouting tiles and/or mosaics today even for large areas such as commercial environments, offices, shopping malls, etc. is achieved using professionals who work through the entire process on their hands and knees. It would be beneficial to provide building contractors, individuals, etc. with a machine to implement some or all of these steps thereby allowing a wider range of tiles and tile effects to be implemented. Equally a handheld unit may be employed by amateurs such as when decorating residential environments in order to improve the quality of their work and reduce the time taken. Such devices according to embodiments of the invention allowing use of smaller tiles, tiling mosaics, etc. without the costs of these visually effective and attractive designs being prohibitive.

A power unit is configured for use as part of a concrete screed and includes a frame and a powered drive. The frame includes a drive housing. The powered drive is operably supported by the drive housing and is configured to rotate a rotatable concrete forming drum. The powered drive includes an electric motor and a battery operably coupled to the electric motor and configured to power the electric motor. The powered drive includes a drive shaft drivingly connectable relative to the drum, with rotation of the drive shaft causing corresponding rotation of the drum.

A power unit is configured for use as part of a concrete screed and includes a frame, a powered drive, and a mechanical control connection. The frame includes a drive housing and a handle to be grasped by a user, with the handle being configured to facilitate manual advancement of the concrete screed in a forward direction. The handle includes a grip and a relatively shiftable user-operated drive controller. The powered drive is operably supported by the drive housing and is configured to rotate a rotatable concrete forming drum.

A power unit is configured for use as part of a concrete screed and includes a frame, a powered drive, and a drive coupler. The frame includes a drive housing and a handle to be grasped by a user, with the handle being configured to facilitate manual advancement of the concrete screed in the forward direction. The handle and the drive housing are pivotally attached relative to each other so that the handle is swingable relative to the drive housing about a pivot axis that is transverse to the forward direction. The powered drive is operably supported by the drive housing and includes a rotatable drive shaft. The drive coupler is attached to the drive shaft and is removably attachable to the connection shaft of a rotatable concrete forming drum so that rotation of the drive shaft is imparted to the connection shaft. The drive coupler is configured to align the drive and connection shafts on a common rotation axis without permitting off-axis swinging of the shafts relative to one another, such that swinging of the drive housing relative to the drum is at least substantially restricted.