Written by: Nikki Alvin-Smith
The Three C’s
When we talked about MASPAR previously an over simplified way to state its advantages for use were noted as the 3 ‘D’ seen here benefits including 3- dimensional corrosion analysis at different depths:
Data Collection with Accuracy and Speed
Disruption Mitigation
Dollars Saved
Similarly simply put, the three ‘C’s’ of the concrete world in material science deserve a look, especially when it comes to mastering the science of technology and how it can be best implemented to help protect the reinforced concrete infrastructure from:
Chemical Attack
Cracking
Corrosion
While a blind man on a galloping horse can find a pothole on a track, a cyclist can find a fissure or fracture in a bridge deck and a structural engineer with reasonable vision can find a crack in a column, it is fair to say that in the modern-day world, building back infrastructure needs detailed diagnostic practices that can prevent the occurrence of imminent defects. Prevention as we know, offers a much better prognosis for good health and longevity than trying to affect a cure.
Our recent featured article here The Magic of MASPAR ~ Wizards at Work with MASPAR – Part II on the EChem Consultants website in regard to the wizardry of multi-array surface penetrating analysis radar MASPAR,certainly defined non-destructive methods of analysis that have and will continue to save time and money for repairs and restoration. This technology provides a more detailed capture and in-depth analysis of data than the vehicle drawn air-coupled devices that more quickly assemble a broadband of data and its use, and the MASPAR is hampered only by its size. Perhaps in the future this may be adapted to a larger model.
The finding of imminent defects on reinforced concrete structures are the bane of the budget, requiring prompt action and ultimately figuring high on the cost scale as a result of that priority. How much better would it be to be able to astutely plan ahead and possibly prevent this urgent necessity of restitution and be able to delineate more clearly what is needed and when.
In medical settings the baseline reading on an X-ray, PET or CT scan, MRI or other finding can provide a sincere advantage when it comes to monitoring adverse or dangerous medical conditions that are clearly in development. Each human body offers its own individual map of normal, and the baseline serves as an essential comparative point for future analysis of both the rapidity and degree of degradation of the skeletal structure. Similarly, forward thinking engineers that seek to bridge the gap between critical fractures and failures in structures and an acceptable rate of progression of degradation that can be carefully and effectively managed with technologies such as externally bonded fiber-reinforced polymer composite systems {EBFRP}, etc. would much appreciate a baseline to exist from which predictive analysis could draw an accurate prognosis for the patient.
Put Your Best Foot Forward
The small but mighty MASPAR may be the small kid on the block, but it is also a machine that when properly operated and specifically quantified in its data acquisition and software intelligence can become the David that outdoes the Goliath. This is due to the quality of the data the ground penetrating radar is able to provide; it is easy mobilization; and the ability to validate its findings in house. EChem Consultants ownership of MASPAR machines facilitates fast access.
As Noyce explained (NRMA Concrete Durability Expert Level 4 and Chief Technical Officer at EChem Consultants LLC) in the previous article MASPAR II where with his renowned wit he referred to the MASPAR unit as a ‘lawnmower’:
“Corrosion on structural elements, such as decks, bridges, and buildings, used to be assessed and evaluated via binocular inspection which was only as good as how close you were able to get to the structure or area of investigation. Conditions visible to the naked eye from that distance are misleading. It was beneficial if you were able to reach and touch the surface you were inspecting, but that was and sometimes is not possible, on a regular basis
This was a rather basic, and fundamentally flawed approach to evaluation of what delamination had occurred or the likelihood of an imminent defect. The MASPAR’s capability to collect accurate data for the analysis of deterioration more than 20 inches below the surface was a game-changer. The non-destructive assessment was further enhanced when we improved the manufacturer’s software that came installed in the machine.”
Structural engineers that conduct in depth evaluations of the viability and durability of RC structures know that a basic exam along the lines of the primary care physician versus a specialist look simply are not enough. A great place to start, but not a great place from which to make decisions on big budget spends. The what, when, where and how need to be identified, and also the ‘who’ will complete the tasks. Identifying the actuality of damage that has already occurred and doing so in a non-invasive but expeditious and cost-effective manner will necessarily require specialist help beyond that of the basic structural engineer job description.
“It is essential that our clientele have accurate information and fully understand the data that is provided and are presented with all the options available for the project at hand. The better versed the client is in the different collection methods for assessment of RC that are available to them and what the tally of results can accurately indicate or predict, then the better and more cost effective the solution can be long term,” explains Noyce.
Use of the MASPAR unit includes scanning and surveying to produce models of delamination, and scans can be overlayed with more detail over those already done. Half-cell and linear polarization offer ‘visionary’ insights into the rate and extent of damage to any part of the structure. However, from a confidence level in regard to evaluation of this information, the rehabilitation, renovation, or restoration on any project can only be authoritatively informed, if there is confidence in how the data has been validated for accuracy and extrapolation.
The different stages of durability in the life cycle of any structure can be measured at a variety of levels using the MASPAR. For example, a basic corrosion analysis of a bridge deck may include corrosion mapping, concrete delaminations, concrete cover, moisture content, and reinforcing steel distribution. While an advanced investigation would ‘dig’ much deeper, providing high resolution crack mapping photography detailing crack width sizing, a lab upgrade module that provides chloride permeability, chloride migration coefficient, time to cracking, and freeze/thaw modeling
The MASPAR data processing algorithm can provide 3D pseudo subsurface images revealing the imperfection and location of steel bars in the reinforced concrete structures. Various critical subsurface information including as-built arrangement and material conditions can be extracted from MASPAR data. This information can be mapped with incredible precision. A few critical maps, in general, produced depending on the job needs:
- Cover Thickness Map – identifies the boundary between topping slabs and concrete layers and represents the thickness of the topping, the placement of the reinforcing steel.
- Moisture Map – MASPAR data can be used to estimate moisture content in the concrete element. These moisture maps can be useful to assess the deterioration risk.
- In some cases, deterioration Maps also can be produced – these maps can indicate the areas that might be actively deteriorating.
“No one entity can develop experiential standards in all areas of structural engineering. Some sort of specialization is essential to provide niche knowledge that can literally save hundreds of thousands of dollars on any given project. Just like the MASPAR unit is not the biggest kid on the block as mentioned above, it does not mean its inherent abilities of detection are not relevant. In fact, quite the opposite is true. What data is collected, its accuracy and detail, how it is collected – meaning its non-disruptive method, and significantly the necessary knowledge to extrapolate and evaluate that data, does not come to hand with engineers fresh out of school with an undergrad degree. Our team regularly works with up-and-coming engineers to guide and instruct them to better understand the technologies and methodologies available both today, and what is coming down the line and how we can influence that to better address future investigation needs,” says Noyce.
In fact, if you look at the structure of EChem Consultants and its team, it is clear that the owner of this W/DBe company, Gina Crevello, takes forward thinking diagnostics and solutions plus the assumed responsibility to help young engineers navigate the present-day world in material science, very seriously. The company is a mirror of Noyce’s principles, and both Noyce and Crevello have some serious experience to share with the next generation.
“I am always interested in working with new talent with a sincere passion for learning both the theory and practical side of corrosion, material and conservation science and durability engineering past undergraduate studies. We { EChem } are consistently working on both the research and development/academic side. Our technical team includes Dr. Shafique Ahmed, who is a noted scholar on many aspects of non-destructive testing and structural health monitoring,” states Crevello.
The Take Home Message on MASPAR
Obviously the MASPAR unit is only one of many diagnostics available to an EChem client.
“Continual monitoring of reinforced concrete via sensors, subscription-based health checkups with a frequency determined by the rate of deterioration, drone thermographic diagnostics alongside air-coupled GPR and MASPAR devices, and all manner of corrosion mitigation is available, such as Impressed Current Cathodic Protection (ICCP), and Chloride Extraction. As with any industry, technology continues to evolve and provide improved diagnostics and remediation options. For EChem Consultants, use of proven initiatives are constantly sought and developed,” says Crevello.
If you’d like to delve deeper into the magic of MASPAR don’t be shy to reach out to EChem Consultants for more information. No matter your level of education in the world of material science, Noyce’s ability to explain the machinations from top to bottom in his British vernacular, imparts both sincere knowledge and a generous forward step for project management personnel.
About Echem Consultants:
Echem Consultants LLC is a material science consultancy whose primary focus is understanding material durability of the built environment. Through our Life 52® assessment approach [Laboratory, Inspection, Field Services, Engineered Design], we assist Architects, Engineers, and structure owners with long-term durability planning and predictive service life modeling for critical infrastructure 52 weeks a year. An additional advantage to employment of EChem Consultants is its ownership status as a certified women-owned business (WBE) and disadvantaged business (DBE) enterprise, thus fulfilling minority requirements for local, state, and federal contracts which have M/WBE or DBE set asides. Echem provides niche expertise in complex problem solving for critical infrastructure, landmark buildings, and new construction.For more information, please contact Echem’s marketing department at 845-215-4370.
About Nikki Alvin-Smith:
British/American Nikki Alvin-Smithi s a seasoned Content Writer with a background in international commerce. Her works have been published worldwide across many genres including construction, investment, international freight forwarding, real estate, travel, the equestrian and pet industry and number in the thousands. Through her media enterprise company Horse in a Kilt Media Inc. Nikki collaborates with a variety of clientele to address their writing and PR needs, from Mom and Pop operators to Fortune 500 companies, from B-list movie/TV celebrities to Olympic athletes. Services include production of creative assets such as ghostwritten books, feature articles, blogs, vlogs, column writing, scriptwriting, speechwriting to copy for Executive Summaries, press releases, event coverage, brand building and marketing strategy. Additionally Nikki Alvin-Smith is an international level Grand Prix dressage competitor, coach and worldwide clinician. Together with her husband Paul, also a Grand Prix dressage rider, she lives in the beautiful Catskill Mountains of New York and operates an organic hay farm and dressage yard.
