A discussion of the paper “Concrete strength by combined nondestructive methods simply and reliably predicted” by H.Y. Qasrawi

Post-installed screws for in-situ assessment of mortar strength

“…In recent years, much researches and studies are carried out where several NDT methods are combined. Several researchers published the successful use of combination of NDTs for strength estimation (Shariati et al 2011, Arioĝlu et al 2001, Martinez-Molina et al 2014, Qasrawi 2000, Pucinotti 2007, Pucinotti 2015, Hannachi 2012, Cristofaro et al 2012. The most widely used techniques for combined method is SonReb method (from UPV and Rebound hammer).…”

“…ACI 228.1R 2003 reported on the marginal improvement of estimation with combined method. Many researchers proposed generalized regression models that were claimed to be useful for any concrete under investigation (Qasrawi 2000, Arioĝlu et al 2001, Nash't et al 2005, Amini et al 2016). Combination may not always lead to improved results (Breysse 2012, Carvalho, et al 2014.…”

Determine the Compressive Strength of Calcium Silicate Bricks by Combined Nondestructive Method

“…Application of the combined nondestructive method is based on tests using the rebound hammer method and ultrasonic pulse method, which is also called the SonReb method and is developed mostly for determining compressive strength of concrete. Testing methodology is specified in the NDT 4 RILEM directive [ 18 ]; relationships for determining compressive strength from ultrasonic pulse velocity and the rebound number are quoted in a series of professional publications, for example, [ 19 – 23 ].…”