Ultrasonic evaluation of cement adhesion in wall tiles

✍ Scribed by K.S. Tan; K.C. Chan; B.S. Wong; L.W. Guan

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 698 KB
• Volume: 18
• Category: Article
• ISSN: 0958-9465
• DOI: 10.1016/0958-9465(95)00008-9

✦ Synopsis

Ultrasound is used to evaluate adhesion in tiled wall systems by measuring the signal amplitude of the ultrasound through the media. Portland cement is used as the adhesive with water-cement ratio ranging from O-3 to 2 by weight. The different water-cement ratio is found to influence the quality of bonding of tile to concrete substrate. The signal amplitude reflected from the tilecement interface shows that high signal amplitude indicates bonds with very high or very low watercement ratios. This is taken as poor bonding because the value of this signal amplitude approaches the signal amplitude from an unbonded tile back. The difference in signal amplitude between poor and good bonds is about 1.9 times or 5.6dB. A water-cement ratio of 0.5 to 06 is found to have the optimum bonding strength (low signal amplitude). This is confirmed by the pullofl test done on the bonded tiles, where the diflerence between good and bad bond is about l*9MNlm2. The elastic modulus of the cement, as determined from ultrasonic measurements, decreases asymptotically with increasing watercement ratio. A low water-cement ratio of 0.3 attained the highest value of 4*12GPa. This does not correlate with the pull-ofs test.