Prediction of cast-in-place concrete strength of the extradosed bridge deck based on temperature monitoring and numerical simulations.

• Augmented maturity method using FEM-based numerical tests in addition to the usual laboratory and field experimental methodology. • Recommendations for an effective laboratory research program and a reliable temperature measurement system. • FEM analysis of compressive strength distribution in the concrete deck of extradosed bridge. • The complex system of concrete monitoring improves the confidence of decisions on prestressing tendons or formwork removal and provides economic benefit. The work is devoted to the implementation of a monitoring system for high performance concrete embedded in the span of an extradosed bridge deck using a modified maturity method augmented by numerical simulations conducted by the authors' FEM code. The paper presents all research stages of bridge construction and considers the conclusions drawn from the results of laboratory tests, field measurements, and numerical calculations. The monitored structure is the largest extradosed bridge in Europe in terms of the span's length. Due to the considerable size and duration of the investment, it was beneficial to use an alternative method for estimating the compressive strength of concrete based on the maturity function. The bridge sections were investigated in three stages: in summer, autumn, and early spring (in June, September, and March). The monitoring of in-place concrete provided information on the actual temperature of the concrete and its gradients. Based on recorded temperatures and proposed numerical procedures, the actual strength of the cast-in-place concrete and the optimal dates of prestressing were determined. This contributed to shortening the work cycle and speeding up the work schedule. [ABSTRACT FROM AUTHOR]