Abstract: A method of determining the compressive strength path of a mortar or concrete mix is presented. The method includes: (a) conducting a series of tests by directing a jet of gas at gradually increasing pressure onto a surface of a freshly mixed test batch of mortar or concrete mix, monitoring the surface of the test sample and recording the pressure of the gas jet at which erosion resistance of the sample surface breaks down; (b) averaging the recorded gas pressure of the tests to obtain a strength index for the sample, and; © relating the strength index to predetermined set index of mortar or concrete compression strength.

Abstract: This invention relates to a method of and apparatus for stabilizing the surface layer of particulate material which is exposed to the elements with the apparatus consisting of dam members which each include sheet material which is formed into an enclosure which may have a plurality of compartments all of which are open top and bottom and the method includes the steps of locating the dam members on or slightly in the particulate material and placing a suitable liquid stabilizing medium in the dam member or its compartments, and allowing the liquid to permeate the zone of particulate material enclosed by the dam member.

Abstract: This invention relates to a method and apparatus for determining the erosion potential of particulate material such as that contained in a mine dump or erosive farmland. The method consists in directing a jet of fluid such as water or air onto the surface of the material from a fixed distance at a fixed pressure or range of pressures and measuring the parameters of the jet against a scale when the jet produces a predetermined effect on the material under test. The apparatus includes a portable accumulator for holding the fluid under pressure, a nozzle through which the fluid may be discharged from the accumulator, means between the accumulator and nozzle for adjusting fluid flow between the two and a portable and adjustable frame such as a tripod on which the apparatus is mounted.

Abstract: The invention is concerned with a method and apparatus for use in the manufacture of paper and board in which pulp in suspension is directed at such an angle and at such a speed towards a screen travelling at a determined speed that the resultant direction of travel of the pulp relative to the screen is substantially at right angles to the screen. In a preferred form of the invention, the pulp suspension is discharged onto the screen as a curtain which extends across a substantial portion of the width of the screen. The invention also provides a chamber into which the pulp is discharged onto the screen, the chamber being sealed at inlet and outlet ends by rollers. The invention further provides for a pulp web formed on the screen to be transferred from the screen onto the roller at the outlet end by means of discharge vents located below the roller and the screen.

Abstract: Apparatus is provided for use in welding together work pieces along a weld line including backing locating means which applies progressively a backing strip over the weld line in advance of the formation of a reverse bead along such weld line and which maintains the flexible backing strip in position over the weld line as the reverse bead is formed along the weld line, first means from which the flexible backing strip is passed to the backing locating means, second means which lifts the flexible backing strip progressively off the weld line as formation of the reverse bead along the weld line is completed and support means which holds the backing locating means, the first and the second means relative to a welding head. Provision is made for the backing locating means to comprise a roller, for a sensing means in the form of a thermocouple for controlling the formation of the reverse bead and for a tracking means for positioning the backing locating means relative to the weld line.