In mechanical engineering surface measurements were initially associated with the
measurement of a surface profile (2D measurement). Even today 2D measurements are still
used, especially in industry. Unfortunately, this type of measurement has serious limitations,
shown in Fig. 1. In the last decades many scientists and designers have become convinced that
the third dimension should be added to the analysis [24−35]. Today the 3D analysis of surface
geometry has become widely accepted, though there is still some disorder in the terminology and
classification of 3D parameters. Various methods are used to measure the surface topography
[36−38]. Most of the existing topography analysis systems are based on a number of profiles,
mostly parallel [39, 40]. Myshkin [41] proposed the following division of measuring methods:
stylus methods, optical methods, SEM methods, AFM and STM methods. A similar, but more
detailed division is shown in [24]. The above methods can be used to measure areas from nm to
mm in size, which is not sufficient for the proper measurement of concrete surface topography.
Therefore, a nonstandard method of measuring the concrete surface topography is needed.
In the case of large concrete surface details, the measured points of an inspected feature are
usually distant from each other. The best solution seems to be an optical method combined with
the coordinate measurement technique [42–45]. There are several optical methods of measuring
the coordinates of 3D objects. They are generally divided into active and passive methods. The
coordinate measuring scanner used in the research (Fig. 2a) is a stereoscopic system based on
two measuring cameras.
The scanner uses the digital light projection (DLP) method and is equipped with measuring
objectives (corresponding to certain measured spaces) and a high-quality projector ensuring
a very high resolution of the cloud of points. Using this scanner one can scan elements from
a few millimetres to a few tens of meters in size. The scanner measurement method is based
on the principle of triangulation (Fig. 2b), consisting in observing the pattern of spectral lines
on the measured detail by two cameras and then calculating a coordinate point for each camera
pixel.