Date of Award
Spring 2005
Document Type
Thesis - Restricted
Degree Name
Master of Science (MS)
Department
Civil, Construction, and Environmental Engineering
First Advisor
Wan, Baolin
Second Advisor
Foley, Christopher
Third Advisor
Wenzel, Thomas
Abstract
Self-Consolidating Concrete (SCC) is a relatively new type of concrete gaining popularity in the construction industry. It benefits construction tasks by eliminating the need for consolidation and can help limit variability in reinforced concrete (RC) structures that may arise due to standard consolidation practices. In addition, SCC improves the overall quality of the concrete matrix by promoting homogeneity and reducing segregation of the constituents. However, the cost of materials can be held responsible for its delayed use in the United States. Likewise, uncertainty of the material's performance and characteristics can also be blamed. Re-verification of certain design parameters is necessary to build confidence in this new building material. It is well known that normal concrete placed in RC structures and consolidated with internal vibration, tends to segregate and settle, causing an upward rise of air and water in the concrete. In the presence of a rigidly held reinforcing bar, this migrating air and water, along with the settlement of other products, tends to cause collections of voids and moisture on the underside of the bar. This poor concrete-steel contact has negative impacts on the bond, reducing it significantly. Evidence is present demonstrating that bars placed with an appreciable amount of concrete below them are the most susceptible to this problem, hence the name, "top-bar" effect. Knowledge regarding the top-bar effect in SCC is very limited. Data regarding this issue, gained through experimentation, is examined in this thesis. Beam-end, pull out specimens, were used to study the relative bond strength of deformed reinforcing bar in both ordinary portland cement concrete (OPC) and SCC. Deductions and comparisons regarding the resulting information on the top-bar effect in SCC are made.
Recommended Citation
Hornyak, Nicholas J., "Top Bar Effect in Self-Consolidating Concrete" (2005). Master's Theses (1922-2009) Access restricted to Marquette Campus. 4807.
https://epublications.marquette.edu/theses/4807