Areas of Interest and Research

Dr. Ramirez's areas of interest are in structural analysis and design, reinforced concrete structures, structural models and experimental methods, as well as prestressed concrete structures. Since joining the faculty in the School of Civil Engineering in August of 1983, Dr. Ramirez has been involved in sponsored research. The research work has dealt with:
  1. Behavior of concrete members with epoxy-coated steel,
  2. Evaluation of load capacity of existing bridges,
  3. Performance of bridge decks with stay-in-place forms,
  4. Alternatives to the current AASHTO bridge sections,
  5. Seismic evaluation of existing bridges,
  6. Computer graphics in the non-linear analysis and design of concrete structures,
  7. Durability of concrete structures,
  8. Earthquake engineering and hazard mitigation, and
  9. Behavior of high strength lightweight aggregate concrete bridge girders.


Dr. Ramirez's research efforts have focused on the solution of engineering problems. It is also important to note that a key component of this work deals with the testing of full-scale elements. In this regard, his work can be divided into five basic research interests:
  1. High-strength concrete
  2. Detailing of concrete members
  3. Earthquake engineering
  4. Bridge design
  5. Durability of concrete bridges

Remarkably, the use of high-strength concrete has preceded full information on its engineering properties. Current understanding of the behavior of reinforced and prestressed concrete members under load (as well as the design procedures now used) is based on the results of experimental studies of concrete members with relatively low compressive strengths, varying mostly form 2000 to 6000 psi. The extrapolation of these procedures to higher-strength concrete is unjustified. Dr. Ramirez's experimental work in this area had dealt with the evaluation of shear-related issues in reinforced and prestressed concrete members for buildings and bridges.

Another research effort deals with the adequate "detailing" of concrete members. There are now numerous computer programs available for the determination of sectional forces for wide variation of structures and loading cases. The analysis process however, is based on an idealized structure, and therein lies the problem. The sectional forces must be transposed into physical arrangements of materials to provide adequate strength. This procedure is a fundamental part of the design process and is referred to as "detailing". Because of the empirical nature of current design procedures, it is not clear how to adequately detail concrete structures in the case of members with complex geometry or complicated loadings. This deficiency could be overcome if the "detailing" process was based on behavioral models rather than on empirical equations. In reinforced and prestressed concrete structures, "truss models" are such behavioral models. They represent load paths that are in equilibrium, and allow the designer to envision the effects of the forces acting on the structure. Dr. Ramirez's work in this area has contributed to detailing of shear reinforcement in concrete members, and it has been implemented in the segmental concrete bridge design specifications of the American Association of State Highway and Transportation Officials (AASHTO).

An earlier research effort has also been directed towards the nondestructive evaluation of in-situ concrete strengths. The evaluation of in-situ concrete strengths is a key component in the repair/strengthening, and load rating of bridge structures and buildings. The "Break-Off" tester developed in Europe has been evaluated to determine if it is a viable procedure to determine concrete strengths. Dr. Ramirez's work was considered by the ASTM in the development of a standard for the use of the Break-Off Tester.

Prof. Ramirez has also been involved in research related to bridge structures. He has studied the bond characteristics of epoxy-coated bars in bridge type members, as well as the durability of concrete bridge decks reinforced with epoxy-coated reinforcement. He has also evaluated the load carrying capacity of bridges, specifically the issues related to:
  1. Continuity in precast prestressed concrete bridge,
  2. Effects of overload vehicles,
  3. Horizontal shear reinforcement in bridge decks with precast panels, and
  4. Alternate sections to the current AASHTO standard bridge girders.
Much of his work has been incorporated into the new Bridge Design Manual of the Indiana Department of Transportation.

Dr. Ramirez has been involved in research dealing with seismic performance of bridges. The January 1994 Northridge, California, and January 1995 Kobe, Japan disasters have occurred near densely populated and industrialized areas. The extent of the damage, and the perceived slow response to the disaster emphasized the need for a coordinated and detailed emergency plan. This is painfully true for regions having relatively low seismic activity as well as the potential for strong ground motions, such as the Midwest. The two events teach an important lesson to structural engineers--the study and implementation of hazard mitigation of existing buildings and bridges in these areas must be accelerated. Our cities in the Midwest are just as vulnerable as Kobe, and the risk in monetary terms and potential for loss of life is extremely high so as to be unacceptable. The southern part of Indiana is one of these areas in the Midwest where the seismic risk is very high. Over the last five years Prof. Ramirez has been involved in research aimed at the earthquake hazard mitigation of existing bridges in the southern part of the state. On January 24, 1994, as part of this study, Prof. Ramirez, under the sponsorship of the Indiana Department of Transportation, went to evaluate the damage to bridges during the 1994 Northridge earthquake. On January 25, 1995, Prof. Ramirez went to Japan as a member of a National Science Foundation (NSF) sponsored bridge team to study the effects of the 1995 Hyogoken-Nanbu (Kobe) earthquake. On October 12, 1995, he visited Manzanillo, Mexico, also under the sponsorship of the NSF, to evaluate building and bridge damage as a result of the October 9, 1995 Manzanillo earthquake. In December of 1995, Dr. Ramirez became one of 30 US engineers and scientists sponsored by the Japanese Society for the Promotion of Science to spend a one-month visit in Japan. During the month of February of 1996 he visited the University of Tokyo, Tohuku University, Kyoto University and the research institutes of the six largest Japanese construction firms. In June of 1996, Dr. Ramirez visited Poland as a member of a delegation of 10 US experts in the concrete field sponsored by the National Science Foundation. In October of 1996, he was a member of a delegation of 8 US experts participating in the US/Central Europe Workshop on Civil Infrastructure Systems for the Next Century: A Global Partnership in Research. The Polish Academy of Sciences and National Science Foundation jointly sponsored this workshop held in Krakow Poland.

Dr. Ramirez has served as referee of technical articles for the ACI, ASCE-Structures, ASCE-Computing in Civil Engineering, ASCE-Transportation, and the Prestressed Concrete Institute Journal.