A rapid field test method to evaluate concrete composite adhesive bonding

Results of an experimental study on a method to evaluate the performance of structural adhesives to repair or upgrade concrete structures have been presented. Tests were made for extremely harsh conditions so that the proposed method can be utilised at field sites as an inspection and evaluation tool. The strength of the adhesive bond is dependent, to a large extent, on how it is cured. Bond strength is a function of the temperature and time at which it cures as well the proper surface pretreatment. Four different adhesive systems were tested by mixing and curing them over a wide range of temperatures (–34 to 49°C). The tests were performed using an innovative bond strength measuring system, which uses a steel shear nut and a torquing system. The results show a dramatic effect of time and temperature of the cure on the bond strength, and significant variation in strengths between the adhesives made by various manufacturers.