Structurally efficient and cost-effective solutions are needed to extend the service-life of deficient and aging highway infrastructure around the world. One critical need is to increase the flexural strength of older reinforced concrete (RC) structures to carry heavier and more frequent loads. Titanium alloy bars (TiAB) offer a new opportunity...
Aging and deficient infrastructure has become a major problem throughout the world. This is particularly evident in the case of reinforced concrete (RC) bridges. The cost of replacing these bridges is often prohibitive, thus engineers must find ways to strengthen them. Many older RC bridges predate the modern understanding of...
Large numbers of reinforced concrete deck girder (RCDG) bridges were built during the highway infrastructure boom of the 1950's. The advent of standardized deformed steel reinforcing bars during this time allowed for straight bar terminations in flexural tension regions. Designers of the time terminated reinforcing bars where they were no...
The behavior of stirrups engaged by diagonal cracks and under service loads is
largely unknown. Full-size laboratory specimens were loaded to induce diagonal
cracks and subjected to high-cycle fatigue loading to represent a service life of 50
years. Tests indicated little change in the average stirrup stress range and mean...
Large numbers of reinforced concrete (RC) bridges were built in the past that are now considered seismically deficient. The structural members most likely to be considered deficient are the supporting columns. Typical deficient columns contain inadequate transverse reinforcement and poorly detailed lap splice lengths above the foundation. Insufficient lap splice...
This thesis is the consequence of a research effort undertaken by the School of Civil and Construction Engineering at Oregon State University and funded by the Oregon Department of Transportation (ODOT) and the Federal Highway Administration
(FHWA). The principal objective of the effort was to reduce the life cycle cost...
Due to age, original design that is deficient by modern standards, inadequate maintenance, environmental conditions, and increasing loads, large numbers of bridges in United States and elsewhere are classified as deficient and in need of rehabilitation or replacement. According to a national bridge inventory established by the Federal Highway Administration,...
Carbon fiber reinforced polymer (CFRP) materials are emerging as an effective means of strengthening and rehabilitating bridges. Near surface mounting (NSM) is a newer technique for application of CFRP for retrofitting of bridge members that provides advantages over conventional strengthening techniques. The technique is still new and uncertainties remain regarding...
Many older reinforced concrete deck girder (RCDG) bridges contain straight bar terminations of flexural reinforcement. Common bridge design practice of the 1950s did not consider the additional demands on the terminated bars from shear and flexure. Moreover, more stringent code specifications and heavier permit trucks contribute to the insufficient ratings...
Fiber reinforced polymers (FRP) are becoming more widely used for repair and strengthening of conventionally reinforced concrete (CRC) bridge members. Once installed, the repair may be exposed to millions of load cycles during service life. The anticipated life of FRP repairs for shear strengthening of bridge members under repeated service...