Abstract: A method and apparatus for optically making physical measurements of materials which deform upon application of heat thereto. The device comprises a source of light, an at least partly transparent chamber having a heating source which can be programmed to operate as a function of time, and with a porous support designed to support a deformable material within the chamber. A photo-electric receiver 5 and an optical lens 7 are also provided for imaging of the material during deformation on the photo-electric receiver. In order to perform the imaging, the source of light, the porous support, the photo-electric receiver and the optical lens 7 are optically aligned. In a specific application, the apparatus can be used to determine the wetting power of pitches.

Abstract: The invention relates to a method of providing a surface dressing for a roadway and includes contacting an aggregate (granular material) and a binder in situ on the roadway and heating the layer thus formed to a temperature measured at about 1mm. below the surface of the layer of betweeen 100.degree. C and 200.degree. C. The method can be applied either to a new surface dressing or to a repair operation and in the latter instance where the surface has become polished as a result of loss of aggregate from the surface, the aggregate is merely distributed over the polished surface and the heat applied to the required temperature.