Automated control of cellulose fibre cement boards with a non-contact ultrasound scanner

Application of X-ray microtomography to quality assessment of fibre cement boards

“…In 1900 he developed and patented the technology of producing damp-proof and nonflammable light-weight, strong and durable asbestos cement sheets, which he called ''eternit" [2,11]. Because of the legal regulations, asbestos (deemed harmful) has been replaced with safe cellulose fibres [11].…”

“…In the long-time limit they experienced the 'tortuosity' of the surrounding material and the slope of <r(s) 2 > reached a constant value. Hence, the tortuosity is defined by (2). In practical condition to determine the slope d < r(s) 2 >/dt, a specific procedure is used.…”

“…Today's fibrecement panels consist of 50-70% of cement while the other components include: mineral fibres (usually cellulose) and fillers (limestone powder, kaolin, etc). Besides being durable, they are characterized by high bending strength, moisture resistance and biological corrosion resistance [2,11].…”

“…Several methods are in use to detect and assess the concentration and dimensions of defects after fabrication. Among them one applies a non-contact testing which applies the emitting and receiving the ultrasound Lamb waves to penetrate the volume of tested bulk material [2], what seems to be effective. However, there is a need to develop the procedures capable to visualize the defects shape and to determine their position within the board.…”

Scanning electron microscopy in the tests of fibre-cement boards

“…It is worth highlighting that so far, the majority of research on fibrecement materials has been limited to determining standard physical and mechanical parameters [5,6]. It is also possible to see the results of research conducted with the use of non-destructive methods, which as a diagnostic method is widely used and simultaneously developed worldwide with reference to steel and concrete constructions as well as composite materials [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23].…”