Optimizing concrete pavement opening to traffic

Abstract

This technical summary reviews the science and strategy behind current practices related to the decision to open new pavement surfaces to traffic and how opening to traffic can be accelerated when necessary. Strategies that enable the pavement to be opened to traffic earlier can shorten construction duration, improve safety by reducing the need for detours, and save costs for both agencies and contractors.

The topics covered in this technical summary include planning and contracting considerations, pavement strength development, traffic loading, pavement stresses, early-age concrete pavement fatigue damage, and materials and construction considerations for early opening of concrete pavements. Nondestructive testing applications for determining when concrete pavements can be opened to traffic are also discussed. Additionally, case studies from Iowa, Georgia, Ohio, California, Virginia, and Indiana are presented.

The current strength requirements set by some state transportation agencies for opening concrete pavements to traffic may be overly conservative. Excessive strength requirements lead to concrete mixtures that may achieve the required strength quickly but may not be durable in the long term. Instances of significant pavement fatigue damage due to early opening were not reported in the case studies or the literature. For opening to traffic, the Strategic Highway Research Program (SHRP) recommends a minimum flexural strength of 300 psi with third-point bending and/or a minimum compressive strength of 2,000 psi. Alternatively, a damage-based online tool has been published that uses early opening damage analysis to determine cracking risks for a given pavement system loaded at a given strength.