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Evaluating mechanical and visco-elastic properties of self-consolidating concrete for cast-in-place bridges
Self-consolidating concrete (SCC) is highly flowable, non-segregating concrete that can spread into place, fill the formwork, and encapsulate the reinforcement without any mechanical consolidation (ACI 237). SCC was introduced as a more durable alternative to conventional vibrated concrete (CVC) in cases of lack of skilled workers. The use of SCC also enhances the quality of surface finish and reduces construction noise and cost because of labor savings. However, SCC has not been used widely in CIP construction in the US due to lack of construction and design guidelines and specifications. Supplementary cementations materials (SCMs)/fillers and chemical admixtures are commonly used to enhance the rheological properties of SCC, which might affect its mechanical and viscoelastic properties. The existing prediction models of these properties do not account for the effect of SCMs/fillers on the performance of SCC. Moreover, most investigations were conducted on high strength SCC used in precast/prestressed applications, however, limited work studied the behavior of SCC in cast-in-place (CIP) applications having compressive strength between 3.5- 6.0 ksi. The objective of this research is to evaluate the mechanical and viscoelastic properties of SCC developed for CIP applications, especially for CIP bridge components and compare these properties with the predictions models in accordance with AASHTO LRFD 2014 provisions and other codes. Several compression, splitting, flexural, push-off, and pull out tests were conducted on large number of SCC mixtures to recommend modification factors for the CVC prediction models when SCC is used. Also, the effects of SCMs, aggregate type, and aggregate size on viscoelastic and mechanical properties were investigated. Full-scale bridge pier and post-tensioned girder were erected and tested to evaluate the constructability and structural behavior of ready-mixed SCC used in field applications.
Asaad, Micheal A. A, "Evaluating mechanical and visco-elastic properties of self-consolidating concrete for cast-in-place bridges" (2016). ETD collection for University of Nebraska - Lincoln. AAI10102747.