In the construction industry, concrete mixes are customized to suit a range of variables including type of application, season of the year, and time of day. As mixing concrete can be highly complex, considerable difficulty ensues for all involved in a construction project when expectations for the final product are not clearly specified and communicated. Accordingly, the industry is forging ahead with a program begun earlier this year — Prescriptive to Performance (P2P) — an initiative of the ready mixed concrete industry, spearheaded by the National Ready Mixed Concrete Association, to promote the use of performance specifications for concrete practice in the U.S. Activities are planned and coordinated through the NRMCA P2P Steering Committee established in October 2002.

The P2P initiative was created to challenge architects/engineers to address concrete specifications in terms of functional requirements as opposed to controlling the specifics of concrete mixtures and construction means and methods. Overall, the process aims to leverage the individual expertise of all project principals, thereby increasing the market share of concrete. Yet, the P2P initiative calls for establishing a parallel track of performance-based specifications alongside the current prescriptive and mixed-format systems: improving the way business is done — not merely changing it — is the primary goal. Existing agreements between contractors and producers specifying mixtures that work for them are not to be disregarded. In fact, partnerships between producers and contractors will be needed at a higher level for successful performance-based specifications.

The success of the initiative depends upon full cooperation between all parties who must thoroughly understand the benefits of the process for themselves. Concrete producers and contractors will be forced to take a progressive approach in achieving desired results more efficiently. Investment by producers and contractors will be required to elevate the knowledge level of their workforce and provide the quality control needed to deliver a performance-based product. By contrast, the current commodity mindset for ordering concrete and the low-bid system for construction stifles any incentive for such investment. Additionally, architects and engineers should be responsible for their area of expertise — designing concrete structures and defining performance requirements to meet the needs of the overall project.

Within their province, producers and contractors must provide mix designs to satisfy the requirements for construction and in-place performance as well as the means and methods to achieve them. If the designer, for example, wants a warehouse floor where curling is minimized, measurable test results must be specified as a means of verifying compliance rather than dictating the type and quantity of cement, aggregate grading, and water content in addition to requirements for shrinkage, permeability and strength. The contractor, then, should have the flexibility to work with the most appropriate tools and methods to achieve the objective.

Prescription specifications limit innovation both directly by over-specification and indirectly by removing economic incentives to improve products and quality control processes. Although the ready mixed industry offers a variety of innovative means to achieve necessary performance metrics, many architects and engineers are not exposed to such resources as readily as the producers, thus limiting application of best practices. Performance specifications allow producers and contractors to work in tandem with engineers and architects to deliver a quality product using mixes that otherwise may not have been considered. Innovation will thereby be fostered, developing new technologies at a faster pace.

Rather than limiting the engineer's input in the formulation of concrete specifications, P2P facilitates the development of an optimized concrete mixture for better quality and economy by focusing on performance and functional requirements rather than mix composition. Further, a performance-based system does not constitute an attempt to hide vital information regarding the concrete mixture as it affects constructibility, jobsite adjustments, and acceptability of concrete. There may be instances where the intellectual property of the producer regarding details of the concrete mix will be retained when a significant amount of time and cost is associated with arriving at the performance-based mixture.

To establish the necessary level of trust among specifiers to move forward with performance-based specs, producers must provide proof of their technical competence and quality-control reliability. Validation of equipment, plants, quality management procedures and employees' level of knowledge by an independent party is one means of establishing credibility. Such a process provides objective verification that producers' policies and operations conform to established industry standards.

Several organizations in the concrete industry currently offer certification. The Truck Mixer Manufacturer's Bureau (TMMB) and the Concrete Plant Manufacturers Bureau place rating plates on truck mixers and concrete plant components to indicate that at the time of manufacture the equipment conformed to standards established by these Bureaus, whose requirements are then reflected in the Specification for Ready Mixed Concrete, ASTM C94. NRMCA offers several certifications for ready mixed producers verifying that their organizations meet the requirements necessary to provide performance-based concrete. Developed through NRMCA committees by association membership for the purpose of elevating the industry, certification programs include Plant and Truck, Production Control Technician (for quality control specialists), Concrete Sales Professional, Concrete Delivery Professional, and the new Plant Operator's Certification. Other NRMCA courses for safety and environmental managers and dispatchers are evolving towards providing a level of recognition for attendees. The American Concrete Institute offers 13 certifications designed to set minimum qualifications for concrete industry personnel, including field technician, inspector, and laboratory technician. In manufactured concrete, the American Concrete Pipe Association, National Precast Concrete Association, and Precast/Prestressed Concrete Institute sponsor plant certification programs for producer members.

NRMCA's Plant and Truck Certification provides a system for verifying that ready mixed production facilities are satisfactory. It reflects — and often exceeds — the requirements of standard specifications for ready mixed concrete, such as ASTM C 94 and AASHTO M 157 as well as CPMB 100, the Concrete Plant Standards of the Concrete Plant Manufacturers Bureau. Certification of plants and trucks under this process validates a company's compliance to basic and standard requirements and reflects its commitment to achieving part of a quality management system. Several state departments of transportation and other specification-writing bodies require that ready mixed concrete producers have certified plants in order to bid for contracts.

The Certified Concrete Sales Professional (CCSP) is a four-module course that teaches and tests for competency in product knowledge, understanding the concrete contractors' job, business skills, and presentations. Recognizing also the key role of mixer truck drivers, the Concrete Delivery Professional program provides comprehensive training and certification for drivers that encompasses considerably more than vehicle-handling proficiency (see Driver Certification sidebar).

As certification in technical product knowledge is essential for delivering performance-based concrete, NRMCA offers a Concrete Technology Short Course comprising four days of training on concrete and aggregate technology, whereby industry-recognized NRMCA Level 2 and Level 3 certifications can be obtained. The new Plant Operator's certification will include five modules with five exams in a comprehensive training program to ensure more efficient batching processes and compliance with regulations.

The P2P initiative, then, is not an attempt to force a change that is not beneficial to all, nor does it aim to remove prescriptive specifications entirely. It is a movement requiring cooperation and partnership between concrete producers and contractors as well as architects and engineers that demands professional standards among all parties to a project. Ultimately, the P2P program endeavors to guarantee that the best concrete is delivered to meet the performance demands of a job, while innovation is promoted and value optimized. — Information provided by National Ready Mixed Concrete Association

DRIVER CERTIFICATION TARGETS KEY INTERFACE

As drivers are the key interface at job sites, ensuring that they have an adequate base of knowledge and understanding of concrete technology is essential to establishing the requisite levels of trust for implementation of performance-based specifications. As part of its recent certification efforts, NRMCA is enhancing its Concrete Delivery Professional program, which tests drivers in five key areas: product knowledge, customer service, safety, environment, and vehicle maintenance and operations. The CDP program goes beyond concrete technology to cover factors integral to company operations, such as customer relations and practices to maintain compliance with environmental and safety regulations.

Certification has been demonstrated to raise morale and increase pride among drivers as well as enhance retention and customer service. Study materials for drivers to prepare for the certification exam are offered by NRMCA at no cost to its members. — National Ready Mixed Concrete Association, www.nrmca.org