ACI certification: A case study
To give a behind-the-scenes look at how ACI creates its certification programs—and to illustrate how such programs provide value to project owners—concrete flatwork finishing certification serves as an example.
The need for a new certification
Large-scale commercial/industrial buildings often require concrete slabs measuring 9290 m2 (100,000 sf) or larger. Conventionally constructed floors in these environments can be problematic. In retail operations, the concrete surface often serves as the finished floor and must be aesthetically pleasing to shoppers. Increasingly, there are also functional needs for very flat floors in retail, big-box spec, and industrial warehouses, as well as logistic and fulfillment centers. These floors must accommodate high-density, tall-rack storage, narrow aisles, robotic equipment, and wire-guided lift trucks operating along pre-defined paths, and extreme loading from heavy installed equipment or warehouse stock.
For the purposes of commercial and industrial floors, floor flatness (FF) measures departures from a theoretically flat plane (i.e. a floor’s bumpiness). Floor levelness (FL) is defined as deviation from a horizontal plane. ACI’s Fmin values represent a separate system from traditional FF and FL. An Fmin number is used to define the lowest acceptable flatness on a superflat floor that has defined traffic patterns (where the vehicle wheels are always in the same wheel path).
|ACI COMMITTEE C640 CONCRETE FLATWORK DEFINITIONS|
|A concrete flatwork associate (formerly concrete flatwork technician) is a person who has demonstrated knowledge (via a written examination) on proper procedures to place, consolidate, finish, edge, joint, cure, and protect concrete flatwork.
A concrete flatwork finisher (formerly concrete flatwork tradesman) is a craftsperson who has demonstrated the skills (via a hands-on performance exam) necessary to place, consolidate, finish, edge, joint, cure, and protect concrete flatwork.
An advanced concrete flatwork finisher (formerly concrete flatwork finisher and technician) is a craftsman who has demonstrated the knowledge and skills and/or experience necessary to place, consolidate, finish, edge, joint, cure, and protect concrete flatwork.
A specialty commercial/industrial concrete flatwork finisher & technician is a person who has demonstrated a basic knowledge of finishing procedures for specialty commercial/industrial concrete flatwork finishing, including high tolerance floor construction, application of surface treatments, and silica fume concrete, and who has demonstrated skill in operating mechanized finishing equipment.
A specialty commercial/industrial concrete flatwork technician is a person who has demonstrated a basic knowledge of finishing procedures for specialty commercial/industrial concrete flatwork finishing, including high tolerance floor construction, application of surface treatments, and silica fume concrete, but who lacks sufficient work experience and verified skills needed to qualify as a specialty commercial/industrial concrete flatwork finisher and technician.
If installed floors are low quality, or even if they are built to outdated specifications, not only will they need extensive repairs during their service life, but also cause wear-and-tear on robotic and other industrial equipment. This translates to unnecessary costs and lost time for facilities managers, maintenance staff, and project owners. Further, some of the benefits of flat floors are not immediately tied to construction concerns. For example, when lift trucks and other moving vehicles can travel easily over floors that are not marred by roughness, cracks, or unevenness, they can handle materials faster, leading to greater facility productivity. They can even navigate tighter spaces, allowing for more consolidated storage and reducing the square footage required for a facility’s operation.
These new demands have brought about specialized methods of concrete floor construction that meet far tighter tolerances than traditional slabs. To address the market’s needs, ACI’s certification department and ACI Committee C640, “Craftsmen Certification,” developed a program titled “ACI Specialty Commercial/Industrial Concrete Flatwork Finisher/Technician” to support a higher minimum standard for all commercial/industrial concrete flatwork. The committee brought together representatives from the materials and engineering side of the business as well as representatives from the application side. Its goal in creating the program was for architects and engineers to drive improvement by specifying a minimum number of people on a flatwork crew are ACI-certified.
The Specialty Commercial/Industrial Concrete Flatwork Finisher/Technician certification program was introduced at World of Concrete (WOC) 2008. Since then, ACI Committee C640 has ensured flatwork certification sessions be consistently held at WOC as well as being offered through various supporting organizations. During a typical two-day program, seminars present information on site preparation and placing environment, high-quality concrete flatwork-related materials, preplacement setup, concrete placement and consolidation, application of surface treatments, and finishing various classes of floors, surface tolerance issues, curing, special considerations for silica fume, and more. Special attention is called to commercial and industrial flatness requirements. Seminar content draws heavily from ACI 302.1R, Guide to Concrete Floor and Slab Construction, and the Silica Fume Association’s Silica Fume Manual.