Pervious Concrete Contractor Certification (PDF)

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					                                                                           As seen in Concrete InFocus, Winter 2008

                        M                 IXED CONCRETE AS

                          te Contractor Cert
           Text reference for

           Pervious Concre

                                                  #2PPCRT. February
                                NRMCA Publication

                   funded by

76   ı   WINTER 2008
                         NRMCA Publication #2PPCRT. February 2007

A World of
NRMCA Pervious Concrete
Contractor Certification
By Colin Lobo, Ph.D., P.E., Senior Vice President, Engineering, NRMCA

          reen building! Sustainable devel-         conventional concrete, and testing stan-     • Procedures and equipment for place-
          opment! Stormwater management!            dards pertinent to pervious concrete do           ment, compaction, finishing and cur-
          LEED certification! Low-impact            not exist at this point.                          ing differ significantly from those used
development!                                      • Production of pervious concrete mix-              for conventional concrete pavement.
    These initiatives provide tremendous            tures needs special attention to aggregate        Improper techniques are immediately
opportunities for concrete as a construction        grading and moisture control and the              evident.
material and specifically for pervious concrete     possible use of admixtures not typically     • The tolerances and techniques for the
pavements. The need to promote pervious             used for conventional concrete. Delivery          placement of pervious concrete make it
concrete pavements was realized very early,         and discharge varies because of the stiff         very specific and require a narrow range of
and these efforts have been very successful. In     nature of the pervious concrete mixture,          timing and techniques.
fact, the resulting demand for pervious con-        the need to retemper at the jobsite, the     • The owner needs to consider additional
crete pavement as a stormwater management           slower rate of discharge from truck mix-          maintenance strategies to ensure con-
option often exceeds the available expertise        ers and scheduling the delivery rate of           tinued performance for the intended
for the placement of pervious pavements.            subsequent loads.                                 function.
    There are some important aspects of                                                               Local and regional groups promoting
pervious concrete pavements that differ                                                          pervious concrete pavements realized that
from conventional pavement design and                The need to promote                         unsuccessful placements would create a
construction:                                        pervious concrete                           negative perception of the technology. To
• The primary design focus is stormwater                                                         prevent this problem, training and certifica-
                                                     pavements was
    management, with a secondary focus on                                                        tion programs were developed by state ready
    structural capacity. Pavement structural
                                                     realized very early                         mixed concrete associations and other local
    design is more empirical, based on expe-         and these efforts have                      groups.
    rience, because the strength of pervious         been very successful.                            Soon it became clear that a national cer-
    concrete generally is lower than that of                                                     tification program would be more beneficial

                                                                                                                           CONCRETE   in focus   ı   77

     in establishing uniform guidelines and cer-        finalized in September 2004. There have                exams and evaluations and verifies that candi-
     tification criteria. This effort was initiated     been two subsequent revisions to keep                  dates meet all the necessary prerequisites and
     by interested members of ACI Committee             pace with the rapidly changing technology.             work experience before awarding certification.
     522 on Pervious Concrete Pavements, led            Regarding the certification program, it was                NRMCA developed a standard presenta-
     by Dan Brown of the Georgia Concrete               decided to essentially use the same certifica-         tion that follows the text as a resource for
     and Products Association. ACI Commit-              tion policies and criteria as used in the ACI          the local sponsoring group to help make
     tee 522 was developing a specification for         Flatwork Finisher certification program.               the task of training certification candidates
     pervious concrete pavements and needed             Two certification levels were instituted:              easier. Two “Train the Trainer” sessions
     to include qualification requirements for          • Pervious Concrete Technician – suc-                  were organized along with placement dem-
     contractors. The task group established                cessfully passing the written exam with            onstrations. Potential trainers from local
     the preliminary criteria for the certification         a 70% score                                        sponsoring groups were invited to these
     program to be administered by NRMCA.               • Pervious Concrete Craftsman – success-               events. Although training is not a require-
     Matt Offenberg, the chair of ACI 522,                  fully passing the written exam, possess-           ment of certification, it is recommend-
     committed to get a training and certifica-             ing a current ACI Flatwork Technician              ed that every candidate go through a
     tion off the ground and running by the                 certification and documenting work                 training program in preparation for the
     fall of 2004. With the assistance of several           experience of 3,000 hours of placing               written examination and performance
     volunteer experts, the NRMCA Pervious                  pervious concrete OR 1,500 hours work              evaluation.
     Concrete Contractor Certification program              experience and passing a performance                   The certification program has been
     was instituted in October 2004.                        evaluation administered by the local               very well received. Many local groups that
         The RMC Research & Education                       sponsoring group.                                  had their own programs have adopted the
     Foundation approved funding to develop                 NRMCA solicited the interest of local              NRMCA program. As of October 2007, there
     a text that would represent the body of            sponsoring groups, with preference given to            are 37 local sponsoring groups administer-
     knowledge deemed necessary to success-             its state affiliate partners, to administer the        ing the certification program. The American
     fully install pervious concrete. The text          certification program at the local level. Local        Society of Concrete Contractors (ASCC) is
     would serve as the basis of the certification      sponsoring groups offer training, the writ-            also a sponsoring group (national) and plans
     program written examination and perfor-            ten exam and the performance evaluation                to administer this program for its members
     mance evaluation. The text document was            and verify work experience. NRMCA grades               at its biannual meetings when there is inter-
                                                                                                               est. There are about 2,000 certified pervious
                                                                                                               concrete technicians and five pervious con-
                                                                                                               crete craftsmen. In its proposed specification
                  Visit our Buyers’ Guide online at
                                                                                                               for pervious concrete, which is working its
                                                                                                               way through the ACI approval process, ACI
                                                                                                               Committee 522 has included a requirement
                                                                                                               for one NRMCA pervious concrete craftsman
                                                                                                               or five pervious concrete technicians to be

                                 ONCRETE C                                                                     on a crew for a pervious concrete pavement
                             R C t Service     HI                                                              installation.
                           TA Grea
                          S g              &S
                                                    PP                                                             NRMCA maintains an online resource for
                                                  s   I                                    N
                   LL vidi
                           n                                                fa                                 the local sponsoring groups and people inter-
                                       316961                                  ct                              ested in obtaining certification at http://www.


                          o                                                                           It also

                                      ALL STAR

                                                                                                               includes a list of currently certified personnel.
                                                                                                                   As with any new program, policies and
                                                                            Safety                             criteria will need to be updated to suit the
                                                                         OSHA Certified                        needs of the technology. The technology is
                                              1/4H/4C                                                          evolving, and there are significant innova-
                                                                                                               tions in concrete mixtures relative to the use
                                       ACROSS THE STATES
                                                                                                               of admixtures and fiber reinforcement and
                                                                                                               in construction methods for a wide variety of

                     Job                                                                   r
                                                                                                               applications, from recreational and residential
                                              PAGE 78                                o
                                                                                b to
                                                                                                               pavement applications to more industrial-type
                                  S                                         o
                       CH mall                                          No J                                   applications with higher anticipated traffic
                         IP P                        T                                                         loading. Construction techniques will change
                                      ING AT IT’S BES                                                          based on the application and the certification
                                                                                                               text will need to be updated continually to

          ı           1
      78 WINTER                                                                                11/3/07   11:36:13 AM
                          NRMCA Publication #2PPCRT. February 2007

           ED PERV



                                                    Pervious concrete is a technology that can help
                                                    designers, property owners and stormwater regulators

                                                    meet the latest stormwater regulations and

                                                    green building standards.

          TE CO NTRA

 accommodate innovation. NRMCA solicits                 written exam at 75 percent, successfully   status for this program, this process will
 feedback to update its text and will incorpo-          passing a performance evaluation admin-    incorporate several useful changes in the
 rate revisions as needed.                              istered by the local sponsoring group,     policies and administration of the certifica-
      In looking back at the established cer-           and documenting at least three success-    tion program.
 tification criteria, there is a large difference       ful installations totaling a minimum of        Finally, a word of caution on certified
 between the numbers for technician and                 10,000 square feet.                        personnel under any certification program.
 craftsman. This is understandable because          • Pervious Concrete Craftsman – pos-           Certification programs only ensure that the
 placing pervious concrete pavements is often           sessing a current ACI flatwork techni-     person has completed established certifica-
 not the primary business of a concrete con-            cian certification, successfully passing   tion criteria and do not speak to reputation
 tractor. Further, among those certified as             the written exam with a 75 percent         or quality of work. Owners wanting to
 a technician, there is no clear distinction            score, and documenting work experience     construct pervious concrete pavements are
 between qualified contractors and those who            (3,000 hours of placing pervious con-      encouraged to follow normal selection pro-
 passed the written exam because of an interest         crete OR 1,500 hours work experience       cesses to ensure successful projects. These
 in the technology.                                     and passing a performance evaluation       include ensuring that the selected contrac-
      NRMCA polled the Pervious Concrete                administered by the local sponsoring       tor has an established reputation and has
 Contractor Certification Committee on                  group).                                    completed successful projects constructing
 revising the certification levels and criteria         Contractors who have passed the writ-      pervious concrete pavements verified by
 to incorporate an intermediate level called        ten exam in the past will be permitted to      appropriate references.
 “Installer,” which acknowledges that there         apply for the Pervious Concrete Installer          Pervious concrete is a technology that
 are many contractors who are installing            certification.                                 can help designers, property owners and
 pervious concrete successfully but have not            NRMCA is currently developing an           stormwater regulators meet the latest
 gained the 1,500 or 3,000 hours of experi-         application for accreditation by the Ameri-    stormwater regulations and green building
 ence required for craftsman certification. In      can National Standards Institute (ANSI)        standards. NRMCA, its state affiliates and
 recognition of this fact, the committee has        for the Pervious Concrete Contractor Cer-      other national partners are dedicated to
 approved the following changes:                    tification Program. The accreditation is       maximizing the success of pervious concrete
 • Pervious Concrete Technician – success-          based on ISO Guide 17024, and the intent       installations through the NRMCA Pervious
      fully passing the written exam with a 75      of obtaining accreditation is to elevate the   Concrete Certification Program.            ■
      percent score.                                credibility of the certification program to
 • Pervious Concrete Installer – possess-           designers and specifiers of pervious con-         For more information, contact Lobo
      ing a current ACI flatwork technician         crete. Regardless of whether NRMCA is          at 240-485-1160 or via e-mail at clobo@
      certification, successfully passing the       successful in obtaining accreditation

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