Katelyn Freeseman, Kyle Hoegh, Lev Khazanovich
Minnesota Department of Transportation
nonstructural testing, Opening strength
The current empirical methods for determining traffic-opening criteria can be overly conservative, causing unnecessary construction delays and user costs. The research described here recommends innovative mechanistic-based procedures for monitoring concrete early-age development and evaluating the effect of early traffic opening on long-term damage accumulation. The procedure utilizes recent developments in nondestructive testing to optimize traffic opening timing without jeopardizing pavement longevity. These tasks were achieved via extensive field and laboratory experiments, allowing for the analysis of variables such as curing condition and loading type with respect to the effect of early loading of concrete. The results of the laboratory and field tests were used to develop a procedure for determining an appropriate timing of subjecting the pavement to wheel loading without causing significant damage. The deliverable for this task is a software program that analyzes the effect of design and opening time decisions on pavement damage. Different criteria are applied for different loading types and roadway design type. This procedure is based upon the maturity and/or shear wave velocity measurements in conjunction with concrete strength and elastic modulus curves, representing in-situ real-time pavement properties. The end result of the software program is a damage ratio that quantifies the damage that results from the opening inputs selected. This tool can be implemented by transportation agencies for optimal timing of traffic opening, making more informed decisions.