This project determines the short term and long term effective stiffness values for Cross Laminated Timber (CLT) with a reinforced concrete topping. The reinforced concrete was attached to the CLT panels with interface connections, and different types of interface connections were tested. Throughout this project, there are 31 tests with...
Use of high-strength steel (HSS) reinforcing bars could provide constructability and economic benefits for the construction of structures, reducing the initial and ultimately the life-cycle cost of bridge and building structural elements. This thesis summarizes work performed in a research project on the use of HSS reinforcing bars for concrete...
The research presented here is a study to determine the effect of shear reinforcement corrosion on the shear capacity in conventionally reinforced concrete (CRC) bridge elements. A total of 14 CRC beams were tested using three stirrup spacings (8, 10, and 12-inch). Six of the beams included the influence of...
High Performance Concrete (HPC) is used in our crucial pieces of infrastructure, such as bridge decks, due to its enhanced durability and engineering properties. However, HPC is highly susceptible to early-age cracking. Cracking within the first months of a bridge deck’s lifespan can severely hinder its long-term performance and durability....
A need exists to develop a non-destructive testing technique that can identify
the formation and propagation of diagonal tension cracks in conventionally
steel reinforced concrete deck girder (RCDG) highway bridges in the State of
Oregon. Such a technique could be included into a structural health
monitoring (SHM) system installed on...
Long-term durability of surface-bonded carbon fiber-reinforced polymer (CFRP) U-wraps for shear strengthening of reinforced concrete (RC) bridge members remains uncertain due to the limited field experience with these materials. This paper provides experimental results from the testing of full-scale RC bridge girder specimens after exposure to prolonged freeze-thaw cycling. CFRP...
Corrosion of embedded carbon steel is a leading factor in deterioration of aging conventional reinforced concrete structures. Methods to accurately predict remaining capacity of corrosion damaged elements, especially shear capacity, are lacking. In this paper, ACI-AASHTO approach, Strut and Tie Method, Modified Compression Field Theory, and Response 2000 were used...
Many conventionally reinforced concrete deck girder bridges (RCDG) and their intermediate supporting bent caps were designed during the Eisenhower interstate era of the 1950’s with the AASHO design equations at the time, which subsequently place higher demand on the concrete. The referenced components may exhibit diagonal cracking due to the...
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...
The Horsetail Creek (HC) bridge is an example of an Oregon bridge that was classified as structurally deficient and was not designed to withstand earthquake (EQ) excitations. A fiber-reinforced polymer (FRP) rehabilitation was performed on the HC bridge to increase flexural and shear capacities for traffic loads. However, a seismic...
Performance evaluation of conventionally reinforced concrete (CRC) bridge superstructure elements with diagonal cracks is of interest to the bridge engineering community. Standardized methods to predict service-level stress magnitudes in cracked bridge girders under combined bending and shear forces are not available. An analysis procedure was developed to determine the response...
Chloride ion migration was studied under accelerated cathodic protection conditions using 6" x 6" x 6" mortar blocks of varying initial chloride content and water to cement ratios. An iron mesh embedded parallel to one face in the blocks acted as the cathode and zinc was thermally sprayed on the...
The effects of steel reinforcement, chloride-induced corrosion initiation, cracking and delamination on the electrical resistivity measurements using the Wenner probe technique were studied experimentally on custom-designed reinforced concrete slabs. Investigation parameters included (1) probe configurations with respect to rebar mesh, (2) rebar density, (3) epoxy coating on the rebar, (4)...
A numerical model for the cathodic protection of steel in reinforced concrete is developed. Parameters are set to represent a three-dimensional section of a bridge beam exposed to the atmosphere and coated with a thermally sprayed zinc anode. Both diffusion of oxygen and conduction of charge within the concrete are...
The migration of chloride ions in concrete with steel reinforcement under cathodic protection was investigated. Mortar blocks (15 cm x 15 cm x 17 cm) of various composition (water to cement ratio, chloride ion content) were cast with an iron mesh cathode embedded along one face and a thermally sprayed...
Three-dimensional finite element models are developed to simulate the behavior of four fill-scale reinforced concrete beams. The beams are constructed with different fiber-reinforced polymer (FRP) strengthening schemes, and are modeled using ANSYS, a commercially available finite element analysis program. The experimental beams replicate the transverse beams of the Horsetail Creek...
The Horsetail Creek Bridge (HCB), constructed in 1914, is located along the Historic Columbia River Highway in Oregon. The original cross beams from the HCB were substantially deficient in shear strength, particularly for the projected increase in traffic loads. One control beam and three beams with varying configurations of a...
Moisture damage has long been recognized as one of the most
critical factors influencing the performance of asphalt concrete (AC)
pavements. This moistureinduced damage occurs from either the
physical separation of the asphalt film from the aggregate or the
softening of the asphalt binder within the AC mixture in the...