Performance-based specifications for concrete

Abstract

Current concrete construction specifications are predominately prescriptive rather than performance-based. However, the balance between prescriptive and performance-based specifications needs to be changed in order to improve the probability of new construction achieving the desired service life at reasonable cost and with minimal disputes. This article presents a hybrid approach for altering current specifications for concrete that is feasible for implementation. The predominance of requirements should be performance related. This would also tend to shift some decisions and risk onto those parties most able to impact the outcomes. Detailed steps are provided on how to implement such a shift in specifications for durability-critical structures. The approach differs from current practice in that emphasis is placed on approving the concrete system (and not just the mixture proportions) before construction. This approval would be based on testing the system rather than depending on broad requirements such as compressive strength or water-cement ratio. Concrete in place would be tested to confirm that it is similar to what which was prequalified and approved.