Application strikes accurate note in CMU compressive strength testing

A new non-destructive method of measuring concrete masonry compressive strength uses the acoustic impulse response of isolated unit specimens. Strike-it technology does not require bulky equipment or specialized facilities, and can be easily deployed in the field, according to British Columbia-based developer SoundQA Solutions.

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SoundQA CEO Neil Cox turned to concrete quality control after a diverse career in industrial research & development and helping create an accredited British Columbia Institute of Technology electrical engineering program. A computer science and mathematics graduate, VP of Technology Spencer Cox applied enterprise software principles to SoundQA’s inaugural product. Strike-it technology testing in cooperation with the NCMA Testing Laboratory and Basalite Concrete Products’ Surrey, B.C. plant has yielded insightful, promising results.

Concrete masonry specimens are placed on a soft surface and gently struck at a prescribed point. The Strike-it mobile app records sound produced in response to the impact and analyzes the attendant signal to estimate the block’s compressive strength. SoundQA engineers recently added a capability whereby the Strike-it Tester can be configured to provide optimized performance for a producer or user’s particular mixes and unit shapes or sizes.

The Strike-it test takes seconds and requires very little preparation or specialized technician training. Records of completed tests can be saved, recalled and analyzed on the Tester, or uploaded for more detailed analyses using a web-based database management system. The app can be implemented on a standard cellphone or tablet computer, greatly reducing implementation costs.

While it is not surprising that the nature of the response to an impulsive stimulus is determined by sample shape and material properties, Strike-it developers underscore the accuracy of compressive strength estimates users obtain. Ahead of commercializing their application and tools, SoundQA engineers’ testing of CMU against conventional destructive measurement procedures indicated the Strike-it method’s propensity to estimate compressive strength within 435 psi up to 95 percent of the time. Under parallel circumstances involving conventional cylinders cast from typical high slump concrete mixes, Strike-it yielded estimates within 580 psi of compressive strength figures logged on traditional lab machines.

EVOLUTION

SoundQA Chief Executive Officer Neil Cox, PhD, P.Eng. and Vice President of Technology Spencer Cox launched Strike-it in August 2019, but enjoyed a premier commercial audience in Salt Lake City earlier this at the National Concrete Masonry Association’s Product Development and Creative Concepts Forum. They demonstrated the simplicity and economy behind their application and tools, and credited the Strike-it platform to an eight-year British Columbia Institute of Technology project involving civil and electrical engineers, physicists and prototype specialists. Team members sought to pinpoint non-destructive methods and devices for evaluating concrete block strength. They aimed for a solution that could use ubiquitous mobile devices to spontaneously measure and record compressive strength findings and eliminate the product handling and waste associated with destructive test methods.

“We are actively pursuing opportunities to supplement and augment existing concrete quality assurance processes in areas where they are well established,” affirms Neil Cox. “We are also pursuing opportunities to introduce Strike-it products in regions where concrete quality assurance is lacking, as no other method provides a comparable combination of accuracy, efficiency, economy and simplicity.” SoundQA Solutions Inc., Burnaby, British Columbia, 604/317-2702; www.soundqa.com