Performance Criteria for Ready Mixed Concrete: Where Are We Today? (Part 1)-Eliminating Prescriptive Requirements for Concrete is an Easy First Step (PDF)

Eliminating Prescriptive Requirements for Concrete is an Easy First Step (PDF)

Pdf Summary

The document discusses the shift from prescriptive to performance-based specifications in concrete construction, emphasizing performance as the future direction. Prescriptive specifications, often seen as a restrictive "recipe" for accomplishing projects, limit innovation and optimization, stifle competition, disincentivize quality management, and impose inappropriate responsibilities. These specifications can cause conflicts and may not ensure intended results due to their rigid nature, detailing specific material proportions and characteristics.<br /><br />In contrast, performance-based specifications focus on defining the desired end result without dictating the methods to achieve it. This approach allows contractors more freedom to innovate and optimize their methods for achieving the specified performance. It encourages accountability since each party is responsible for their work, emphasizing a clearly defined end result and objective, quantifiable testing methods.<br /><br />The document provides examples of the common issues with prescriptive specifications, such as unnecessary restrictions on concrete mixture proportions, maximum water-to-cement ratios, minimum cementitious content requirements, and limits on supplementary cementitious materials (SCMs) and aggregate grading. These limitations often lead to higher costs, reduced performance, and inefficiencies in project execution, counter to sustainability goals.<br /><br />The document also highlights an industry survey assessing the prevalence and impact of prescriptive requirements, with findings indicating a significant portion of specifications being overly prescriptive. It suggests that adhering to widely accepted standards, such as those from the American Concrete Institute (ACI), could alleviate these issues. The push for performance-oriented specifications is framed as an evolution toward better industry practices, with resources and case examples cited for guiding those interested in transitioning to performance-based specifications.

Keywords

performance-based specifications

prescriptive specifications

concrete construction

innovation

optimization

quality management

sustainability

American Concrete Institute

industry survey

project execution