Projects › Current

NEES-II System Behavior Factors for Composite and Mixed Structural Systems

NEESR-II: System Behavior Factors for Composite and Mixed Structural Systems.
Principle Investigators: Roberto Leon, Georgia Institute of Technology; Jerome Hajjar, University of Illinois; Tiziano Perea, Georgia Institute of Technology; and Mark Denavit, University of Illinois.
This project is a NEESR-II award with the aim of developing system behavior factors for frames with composite beam-columns subjected to seismic loads. The system behavior factors to be developed in this research include the structural system (R) factor, lateral displacement amplification factor (C_d), and the system overstrength (Ω₀) factor. In order to reach these goals, analytical and experimental studies will be conducted on both rectangular and circular concrete-filled tubes (RCFT and CCFT) and encased (SRC) shapes. The analytical studies will include parametric fiber and finite element analytical models. The experimental part to be conducted at MAST includes testing of 24 full-scale slender composite beam-columns (10 CFT, 8 RCFT and 6 SRC) to evaluate their strength, ductility and stiffness under large lateral displacements.

NEESR-II: Inelastic Web-Crushing Performance Specimen

NEESR-II: Inelastic Web-Crushing Performance Limits of High-Strength-Concrete Structural Walls. Michigan State University.
Principle Investigators: Rigoberto Burgueno, Michigan State University; and Eric Hines from Tufts University.
This project will use the MAST 6-DOF Test System to investigate and establish rational performance levels for the development of seismic assessment and design approaches to high-strength-concrete (HSC) structural walls based on ductile shear failure mechanisms. The experimental component of the research is divided in two parts. Part I - Structural Wall Characterization: Investigation of the fundamental mechanisms and limits of dependable web crushing failures in HSC structural walls with confined boundaries for ductile shear response through pseudo-static tests on single walls with concrete strengths of 5, 10, 15, and 20 ksi. Part II - Wall Assemblies Characterization: Investigation of the three-dimensional behavioral mechanisms and the web-crushing performance limits of structural wall systems in the context of a hollow pier through multi-axial pseudo-static tests on two HSC wall-assembly test units with concrete strengths of 5 and 20 ksi.

Kansas Purdue Uni-directional Concrete Column Test

Project NEESRGC: Mitigation of Collapse Risk in Vulnerable Concrete Buildings. University of California at Berkeley. Principle investigators: Adolfo Matamoros, University of Kansas; and Julio Ramirez, Purdue University.
The project will use the multi-directional loading capabilities of the MAST advanced 6-DOF control technology to study column behavior as it has not been done to date. The proposed experimental program will include 24 full-scale, rectangular cross-section columns. The specimens tentatively will have dimensions of 18x18 in. Specimens will have ~4,000-psi concrete with Gr. 60 deformed bars