LIVE-LOAD DISTRIBUTION FACTORS AND SERVICE RESPONSE OF MISSOURI BRIDGE A7957

Abstract

During the last years, self-consolidating concrete (SCC) has become widely accepted because of its primary benefits that include a higher construction and cost effectiveness compared to traditional concrete mixtures. Innovative materials such as high volume fly ash concrete (HVFAC) represents a significant potential to producing stronger and more durable cast-in-place (CIP) concrete elements. Bridge A7957 is the first large-scale implementation of these materials conducted by the Missouri Department of Transportation (MoDOT) in Missouri, USA. A level of 50% fly ash to cement proportion, as well as self-consolidating concrete (SCC) with two different strengths was employed in the construction of Bridge A7957. The purpose of this study was to conduct an in-situ evaluation of the precast prestressed (PC/PS) concrete members of the bridge superstructure. To attain this objective, Bridge A7957 was scheduled to be monitored at different serviceability stages. A field load test was conducted to investigate the overall bridge’s response under static loads. During the live load test, the girders’ vertical deflection was obtained with an automated total station (ATS). Based on measured results, the flexural lateral distribution factors were computed. The AASHTO LRFD Bridge Design Specifications were also used to compute the flexural lateral distribution factors, which were found to be conservative.