Issued as a Documentation Report on an Investigation of Field-Made Joints in Prestressed Reinforced Concrete Highway Girder Bridges, Project IHR-303, Phase 2

A prototype bridge girder was designed, built, and tested. The 250 ft long two-span girder was made of 3 precast segments about 88, 74, and 88 ft in length. The segments were supported on 3 final and 2 temporary supports. The joints were of cast-in-place concrete, as was the composite deck. After the site-cast concrete was cured, the structure was post-tensioned to establish continuity and the temporary supports were removed. The two longer segments were pretensioned to resist the girder and deck dead loads, while the shorter segment was reinforced with deformed bars for the same loads. The structure was subjected to a series of loadings, during which deflections, reactions, and concrete strains were measured. The loads approximated AASHTO HS-20 vehicles. The first 4 tests ,were to service loads, with total applied loads of 73.6 kips. The structure remained elastic and crack free during these tests. Two tests were to the design ultimate load, 198.7 kips. A load of 328.2 kips was applied in the final test without causing failure. The final loading was applied to produce maximum shear in one splice, and a shear failure, complicated by large flexural deformations, appeared to be developing when the test ended. The final test produced a maximum deflection of 10.8 in., and a residual of about 1.0 in. The joint details used in the prototype structure were adequate, and the presence of the, joint had no influence on the behavior of the structure until extremely large overloads were reached.State of Illinois Department of TransportationU.S. Department of Transportation. Federal Highway AdministrationProject IHR-30

Thick Walled Multiple Opening Reinforced Concrete Conduits

The Department of The Army Corps of Engineers, Engineering Division, Civil Works, Contract No. DACW-73-70-C-003

Detection of freeze injury in oranges using magnetic resonance imaging under motion conditions

Magnetic resonance imaging (MRI) is applied for on-line inspection of fruits. The aim of this work is to address the applicability of MRI for freeze injury detection in oranges directly on a distribution chain. Undamaged and damaged oranges are conveyed at 50 and 100 mm/s by a specially designed conveyor within a 4.7 T spectrometer obtaining fast low-angle shot images. An automatic segmentation algorithm is proposed that allows the discrimination between undamaged and damaged orange

Highly-parallelized simulation of a pixelated LArTPC on a GPU

The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

Issued as the Final Report on the Field Investigation of Prestressed Reinforced Concrete Highway Bridges; Project IHR-93, Illinois Cooperative Highway and Transportation Research Program

Work accomplished over the 14.5 year life of this project is summarized, and the reports published as part of the study are referenced. Implementation of the results of the study has already been accomplished in two areas. The current loss-of-prestress provisions in the AASHTO Bridge Specification are based on recommendations prepared as part of the work of this project. Illinois DOT has stopped using span diaphragms in prestressed concrete highway bridges as a result of recommendations based on another phase of the study. The work may be divided into three relatively separate phases. The first phase was the installation of deformation measuring instrumentation in three in-service bridges, the gathering of data, and the development of analysis procedures that enabled the data to be interpreted. second phase involved the construction of relatively small scale prestressed bridge components, and their use to provide data to help confirm some information developed in the field study. The models were later tested to failure, and additional information about overload behavior was gained. The third phase was a study of the effects of span diaphragms on moment distributions in bridges, and it was concluded that these members were cost-ineffective and that their use should be discontinued.State of Illinois Department of TransportationU.S. Department of Transportation. Federal Highway Administratio

Strength Of Slabs Subjected To Multiaxial Bending And Compression

Flexural strength of reinforced concrete slabs with externally applied in-plane forces, by A. G. Girolami, M. A. Sozen [and] W. L. Gamble; and Strength of slabs subjected to multiaxial bending and compression, by W. L. Gamble, H. Flug [and] M. A. Sozen.Summary of Flexural Strength Of Reinforced Concrete Slabs With Externally Applied In-Plane Forces by Girolaml, A.G.: Reinforced concrete slabs, bounded by elements which can develop horizontal reactions, have flexural capacities considerably in excess of the load calculated by an orthodox application of the yield-line analysis. The additional capacity results primarily from changes in geometry of the slab which generates in-plane forces reacting against the bounding element. Calculation of the effect of the in-plane forces on slab flexural strength is essential for a realistic evaluation of the slab capacity because the increase in load caused by the in-plane forces is not negligible, especially for short-time loading. The investigation described in this report was concerned with the development of a simple method of calculation for the flexural strength of reinforced concrete slabs with in-plane forces and to check the applicability of the method by experiments. Six reinforced concrete slabs with spandrel beams were built, instrumented, and tested. The test slabs, which were six-ft square and 1.75 in. deep, were reinforced with intermediate grade steel ( yield stress was approximately 48,000 psl ) and the concrete strength was approximately 4500:psl.. The slab and the spandrel beams had both negative and positive moment reinforcement to stimulate an interior panel in a two-way slab designed to carry 150 psf. Three of the test slabs were supported only at the corners while three were supported at several points along the spandrel beams to investigate the effects of nonyielding beams... Summary of Strength Of Slabs Subjected To Multiaxial Bending And Compression by Gamble, W.L.: Reinforced concrete slab panels which are supported so that horizontal displacement of the edges of the panels are prevented are often capable of supporting considerably more load than would be indicated by simple yield-line analysis methods because of in-plane compression forces developed during deflection. The purpose of the series of tests and analysis described in this report was to demonstrate that the basic principles used in predicting the strength of reinforced concrete elements subjected to bending moments and thrusts in one direction, as in the case of columns, can also be used satisfactorily to predict the strength and behavior of slabs subjected to bending and in-plane forces acting in several directions at once. The importance of the in-plane forces can perhaps be best illustrated by reference to a set of tests conducted by Ockleston on a large reinforced concrete building. A single interior beam-supported panel carried a uniformly distributed load of 753 psf. While the computed capacity, using the yield-line analysis technique, was 295 psf. The very high load capacity is attributable to the presence of –in-plane compression forces generated when the surrounding panels restrained the lateral movements of the edges of the load panel. Six hexagonal reinforced concrete slabs were constructed and tested in order to investigate the effects of the reinforcement ratio and magnitude of in-plane forces on the strength and behavior of slabs. The slabs were reinforced with steel having a yield stress of about 50 kips/in. ² and the average concrete strength was about 6,300 1b/in.² The slabs were four in. thick, and the basic hexagon measure about 6 ft 2 in. across flats. The edges of the hexagon were slotted to form loading wings, and the load was applied so as to produce constant bending moments in all directions within a three ft diam. Central portion of the slab...The Departmeent Of Defense Office Of The Secretary Of The Army, Office Of Civil Defense. Contract DAHC 20-67-C-0136, Subcontract 12472 (6300 A-030) US, OCD Work Unit 1127

Field Investigation of Prestressed Reinforced Concrete Highway Bridges : Instrumentation For Long-Term Field Investigation

Issued as part of Progress report no. 2 of the Field investigation of prestressed reinforced concrete highway bridges, project IHR-93, Illinois Cooperative Highway Research Program, conducted by the Structural Research Laboratory, Department of Civil Engineering, Engineering Experiment Station, University of Illinois, in cooperation with the State of Illinois, Division of Highways, and U.S. Department of Transportation, Federal Highway Administration, Bureau of Public Roads.Project IHR-93 , Illinois Cooperative Highway Research Progra

Issued as a Documentation Report on The Field Investigation of Prestressed Reinforced Concrete Highway Bridges Project IHR-93, Phase 1, Illinois Cooperative Highway Research Program

State of Illinois. Department of TransportationU.S. Department of Transportation. Federal Highway Administratio

Ribbed Slabs Under Concentrated Loads

Studies of ribbed slabs subjected to single and multiple concentrated loads were carried out on both one-span and two-span continuous structures. The ribbed slab was decomposed into a series of beam and slab elements. Joint forces of the decomposed structure were determined under the condition that forces and displacements of both elements at each joint. be equal. A solution for the structure under the applied loads was obtained by substituting the calculated joint forces into the equilibrium equations of the individual elements. The results obtained were internal moments and forces in the ribs due to the applied loads. Also calculated were the equivalent uniformly distributed loads on the ribbed slabs subjected to multiple loads such as might be found in parking garages

Issued as a Documentation Report on The Field Investigation of Prestressed Reinforced Concrete Highway Bridges, Project IHR 93, Phase 1, Illinois Cooperative Highway Research Program

Theoretical time-dependent deformations and prestress losses in pretensioned, prestressed simply supported concrete girders, based on the revised rate of creep method, are presented. The effects of age of precast girders at the time of casting of the deck concrete, time of transfer of prestress, deck dead load, type of prestressing strands (stress-relieved or low-relaxation strands), initial level of stress in the concrete, and the effects of varying environmental conditions on the behavior of concrete structures are studied. Predicted unit creep and shrinkage strains versus time relationships are based on the 1970 C.E.B. recommendations and relaxation losses for stress-relieved strands are estimated using the expressions developed by Magura, Sozen, and Siess. A similar expression is used for the case of low-relaxation strands. Predicted deformations are compared with long-term measurements made on full-sized bridge structures located in Illinois. Annual cyclic variations of the total strains and total prestress force occur in all structures located outdoors. Two recommended sets of factors for the estimation of prestress losses are given, one for the case of stress-relieved strands and the other for the case of low-relaxation strands.State of Illinois Department of TransportationU.S. Department of Transportation. Federal Highway Administratio