Abstract: A method of erecting multi-story buildings by joining spaced elongated vertical columns of concrete. The method comprises providing a screw threaded metal socket in the face of each column to be connected. The socket of one column has a thread opposite in direction to that of the socket in the other column. One column is disposed over the other with the mouth of the sockets aligned.

Abstract: A method of joining together two concrete bodies each having a concrete reinforcing bar, the method involving compressing a gripping portion of a metal sleeve on the end of the first bar with the metal sleeve also having an unpressed portion which extends beyond the bar, the unpressed portion having an internal diameter larger than the maximum cross-sectional dimension of the second of the bars, and securing an end of the second of the bars within the unpressed portion of the sleeve by means of a self-setting composition.

Abstract: Connecting reinforcing bars in an access hole by a method and means which comprises:(1) securing to each first bar by a radial compression the unthreaded portion of a first partially internally threaded sleeve,(2) securing to each end of a connecting bar the unthreaded portion of a second partially internally threaded sleeve, the connecting bar being of a length slightly less than that between the sides of the hole,(3) locating in the threaded portion of the second sleeves at each end of the connecting bar a threaded high tensile externally threaded stud and locating the connecting bar between the first bars in the sides of the hole,(4) rotating each stud to engage a threaded sleeve secured to a first bar so to bridge the gap between the first bars by means of the connecting bar.