Field Experience and Structural Performance of Self-Consolidating Concrete in High-Rise and Bridge Construction-Shear and Bond Strength of Self-Consolidating Concrete for Cast-in-Place Bridge Applications (PDF)

Shear and Bond Strength of Self-Consolidating Concrete for Cast-in-Place Bridge Applications (PDF)

Pdf Summary

The study presented by George Morcous and Michael Asaad focuses on the shear and bond strength of self-consolidating concrete (SCC) for its application in cast-in-place (CIP) bridge construction in the United States. SCC's limited use in this domain is attributed to the lack of design specifications and construction guidelines, along with concerns about its structural performance and durability.<br /><br />The research aimed to propose amendments to the AASHTO LRFD Bridge Design and Construction Specifications to include SCC for CIP bridge components. It involved developing SCC mixtures, evaluating their fresh and hardened properties, and comparing experimentally measured properties, such as shear and bond strength, against predicted values.<br /><br />A comprehensive approach included a literature review and a survey across 17 state departments of transportation to understand the current practice concerning SCC usage, constituent materials, and testing methods.<br /><br />Results indicated that while interface shear resistance of SCC is claimed by some studies to be higher than conventional concrete (CVC), findings vary, and SCC's shear resistance when measured aligns closely with predictions under the AASHTO LRFD model. However, it was noted that AASHTO LRFD might overestimate shear resistance for SCC with compressive strengths below 6 ksi.<br /><br />Regarding bond strength, the study found that SCC generally has lower bond strength with vertical reinforcement compared to CVC, suggesting a modification factor of 1.3 to development length for accurate predictions. High slump flow SCC showed reduced top bar effects compared to CVC.<br /><br />Overall, the study concluded that while SCC can achieve similar nominal shear resistance to CVC at various reinforcement levels, adjustments to specifications are necessary for enhanced precision and application in bridge construction. The study suggests revisions and further research into SCC applications to bolster its acceptance for use in U.S. infrastructure projects.

Keywords

self-consolidating concrete

shear strength

bond strength

cast-in-place bridge construction

AASHTO LRFD

concrete design specifications

structural performance

construction guidelines

SCC mixtures

infrastructure projects