Non-destructive evaluation of solid fired clay brick strength using the SonReb method

This research explores potential non-destructive testing (NDT) methods for assessing the properties of solid fired clay (SFC) bricks in situ. Empirical correlations were established between the results from NDT and the compressive strength determined through traditional destructive testing (DT) techniques performed in a controlled laboratory setting. The research focuses on two specific NDT methods: the Rebound Hammer Test (RHT) and Ultrasonic Pulse Velocity Test (UPV), alongside their integration into a combined approach referred to as the SonReb method. The RH method utilises the Q-value, a dimensionless parameter derived from the ratio between the kinetic energy measured of the reflected and forward hammer mass. The UPV test involves measuring the speed of ultrasonic waves travelling through the solid brick material. A total of 234 DT and 476 NDT were conducted on both modern and historical SFC bricks. The research accurately validates the application of the RHT on SFC bricks for determining compressive strength from the Q-value. Additionally, the study validates the SonReb method by testing SFC bricks and comparing the experimental compressive strength NDT value with obtained through DT. A novel empirical equation is proposed to estimate the compressive strength of the SFC bricks based on the SonReb method. Findings demonstrate an accurate relationship between NDT readings and the compressive strength determined by destructive methods on SFC bricks. Moreover, the results emphasise the reliability of the SonReb method in estimating compressive strength, providing a useful tool for in situ structural assessment of SFC bricks.