In 20 years as a testing technician for the National Concrete Masonry Association (NCMA) — and 16 years as a mason contractor before that — Doug Ross has seen his share of problems with masonry materials. Now the manager of research and development for NCMA, Ross is often asked to conduct testing for labs that don’t have specialized equipment for masonry, or to provide a third-party analysis when an issue arises on a particular project.
“Recently a job was shut down due to a problem with an absorption value and the block producer wanted us to do additional testing,” says Ross. The ASTM standard recently changed for the type of block that was being tested, requiring a larger section of block to be used in the test. “The first lab may have used a small or defective sample. Little errors in testing can be detrimental to strength and absorption values.”
It’s not uncommon for inaccurate testing procedures to result in failed inspections of perfectly sound masonry structures. Jacob Burgess, manager and senior technician for Nelson Testing Laboratories in Elmhurst, Ill., echoes Ross’ experience. “Many mistakes are made during the casting and storage of masonry specimens on the jobsite,” says Burgess, “and additional mistakes are often made in transporting specimens back to the laboratory. These errors will often lead to improper results.”
Both Ross and Burgess recently completed two new certification programs developed by the American Concrete Institute (ACI). The Masonry Field Testing Technician Certification and Masonry Laboratory Testing Technician Certification programs are designed to verify the technician’s knowledge and skill set related to these specific areas.
“Testing masonry in the field is probably one of the most incorrectly executed aspects of construction,” says Chris Robinson, chair of ACI Committee C670, Masonry Technician Certification, and executive director of the Construction Materials Engineering Council (CMEC), a laboratory accrediting body in Orlando, Fla. “There are discrepancies with sampling and testing in the field as well as discrepancies that occur in the laboratory.”
Robinson sees these problems frequently in Florida, where the volume of masonry construction is higher than in other parts of the country. Therefore he was well-qualified to chair ACI Subcommittee C601-C, Masonry Testing Technicians, which developed the masonry-specific certification programs. Committee members included representatives from The Masonry Society (TMS), the National Concrete Masonry Association (NCMA), and the Portland Cement Association (PCA); all of which continue to support the programs’ implementation.
The Masonry Field Testing Technician and Masonry Laboratory Testing Technician programs were launched in 2014 with TMS as the program’s national sponsor, offering two-day seminars. Some local ACI chapters and sponsoring groups are also offering review sessions, or are teaming with TMS to offer this program in their markets.
Each session includes one day of classroom instruction and hands-on practice, and one day of written and practical exams. The laboratory technician review focuses on topics such as proper storage of test specimens in the lab, fabrication of test specimens, testing of grout prisms, mortar cubes, CMU’s, and specimen preparation for compressive strength testing. Masonry field testing technicians learn how to properly sample CMU’s , perform a slump test on masonry grout, prepare and construct specimens that will be tested in a lab, proper jobsite storage of test specimens, and how to transport specimens back to the laboratory.
ACI, TMS, and ASTM have teamed up to produce online training courses that will soon be available. These online courses can supplement the classroom and hands-on training or serve as an update or refresher course when technicians need to be re-certified every five years.
Although the masonry technician certification programs are based largely on ASTM standards that testing technicians need to have extensive knowledge, other stakeholders can attend. Building officials, block producers, contractors, and specifiers can benefit from understanding basic information such as what needs to be tested, why testing is performed, common errors, typical results to expect, what can impact test results and what to do if there is a problem. (Anyone can register and participate in the first day of instruction and review without taking the exams.)
Phil Samblanet, TMS executive director, has organized review sessions in several states including Virginia, Illinois, Arizona, and California. “For many years, masonry was built ‘prescriptively,’ using the same materials and techniques that had always been used, so testing was not commonly required,” he says. “Now with a greater focus on high wind and seismic considerations, reinforced masonry is often needed. With thinner reinforced masonry walls and more elaborate designs, there is a greater expectation to verify material properties.”
At the same time, following the correct standards for testing masonry materials has become more complicated. For example, changes in procedures for constructing masonry prisms have caused confusion in the industry, and different methods for testing in the field versus the laboratory are often applied incorrectly.
“Huge problems have been associated with the incorrect specification of test procedures,” says Robinson. “Often the wrong test method is specified, or none at all.” However, he says, technicians who have completed masonry testing certification will be able to recognize such discrepancies and correct them in time.
“If we’re going to require testing, it needs to be done right,” says Samblanet. “Otherwise owners don’t know if bad test results indicate a problem with the materials, construction, or the testing itself — it just creates a lot of headaches.”
Testing technicians are currently earning masonry certification on a voluntary basis, but efforts are underway to make it a requirement. The next edition of The Masonry Society’s TMS 602 Specification for Masonry Structures, requires the use of qualified testing technicians. Its commentary cites the ACI certification as one way to determine that technicians are qualified to perform field and laboratory testing.
“This is really significant, and it’s what has to happen for the certification to be fully adopted,” says Michael Morrison, ACI manager of certification program development. “But it’s also critical to include it in the ASTM specification as this will ensure laboratory participation and compliance as well.”
Morrison says lab and field technicians already have to be certified to test concrete and concrete aggregates to become accredited. Certification for masonry testing is a logical next step.
“It can be as simple as saying ‘technicians shall be certified.’ The labs can decide how it’s done,” says Robinson. In 2017 his organization, Construction Materials Engineering Council, will begin requiring labs to have at least one person certified to test masonry materials to receive accreditation for masonry testing services.
ASTM Subcommittee C1093, Standard Practice for Accreditation of Testing Agencies for Masonry, is currently considering a ballot to add the certification requirement to the specification.
In the meantime, technicians can set themselves apart by becoming certified for masonry testing; a credential Samblanet says will become more important in years to come. “Contractors don’t want to hire people who are going to cost them more time and money on the job by not performing tests properly. They need someone they can trust.”
But beyond professional credentials and lab accreditation, ACI’s vision for masonry testing certification aims at boosting confidence in masonry as a building system of choice.
Building a better understanding
Education is the key to making the testing process go more smoothly, says NCMA’s Doug Ross. Accredited labs with certified staff are more likely to produce more accurate test results, but even if samples are being sent to a third-party lab, educated technicians can confirm the correct materials are being supplied. They can also add value on the jobsite, helping address potential problems or answering questions.
“When I was a mason in the field, I don’t think I ever knew exactly what the testing technicians were doing when they showed up on the job,” recalls Ross, “but it really benefits masons to communicate with technicians and understand what they need. It’s in their best interest to produce the best samples possible, to help reduce headaches down the road.”
Completing a successful project, he stresses, is a joint effort. “All three aspects — materials production, masonry construction, and testing — need to be right.”
For more details, visit the ACI website or read “New Programs for Educating and Certifying Masonry Testing Technicians”.
For information about training sessions, see The Masonry Society’s website.
Watch a video about ACI's masonry testing programs.