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Clinker Microstructure and Grindability: Updated Literature Review
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Item Code: SN2967
Date of Publication: 2007
Price: $0.00
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Much of the available literature on the relationship between clinker microstructure and grindability agree that the primary influential factors are alite and belite crystal size and content. Specifically, smaller crystals and more alite (less belite) result in easier to grind clinker. Numerous equations are found in literature to predict clinker grindability based on its microstructure, and although the equations vary somewhat, the relationship to alite and belite content and size previously described are consistent.
On a related topic, some literature was found on clinker microstructure and grindability with the focus on the influence of trace elements, this topic arising likely due to the increased use of alternate raw materials and fuels.
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Construction and Testing of 1/10-Scale Micro-Concrete Model of New Potomac River Crossing I-266
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Item Code: RD031
Date of Publication: 1975
Price: $0.00
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A micro-concrete model of one-half of a proposed three-span box-girder bridge over the Potomac River near Washington, D.C., was built and tested to destruction. The model was constructed by the segmental cantilever method and post-tensioned in three directions. Extensive measurements of steel and concrete stains, deflections, and rotations were recorded during construction and subsequent load testing. The observed behavior of the model was compared with computed values. Test results showed that this very large prestressed box-girder bridge designed by existing specification will perform satisfactorily. This report is also found on DVD021.
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Design of Bent Caps for Concrete Box-Girder Bridges
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Item Code: RD032
Date of Publication: 1975
Price: $0.00
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Presents design recommendations for integral bent caps in straight, continuous box-girder bridges as the result of a combined experimental and analytical investigation, Project 12-10 in the National Cooperative Highway Research Program. With two models of complete bridges and five models of bent cap portions of bridges, the project team investigated distribution of loads on bent caps, effect of flaring the column in the plane of the bent, effective flange width of the bent cap, effect of spreading the main tensile reinforcement into the adjacent superstructure, and location of the critical design sections. An elastic folded-plate solution and a finite element model were used to predict behavior. This report is also found on DVD021.
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Design of Reinforced Concrete for Fatigue
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Item Code: RD059
Date of Publication: 1978
Price: $0.00
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Report of experimental investigation to determine the fatigue strength of deformed reinforcing bars, which was sponsored in part by the National Cooperative Highway Research Program. Each test bar was embedded as the main reinforcing element within a concrete beam. Test variables included size of beam, size of bar, grade of bar, bar deformation geometry, minimum stress, and stress range. A total of 353 tests were carried out. Design provisions were developed by statistical procedures from the test data. An example of application of the provision in the bridge design is given. This report is also found on DVD021.
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Design Ultimate Load Test of 1/10-Scale Micro-Concrete Model of New Potomac River Crossing, I-266
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Item Code: RD011
Date of Publication: 1971
Price: $0.00
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Describes details of making and testing a 1/10-scale model of a proposed three-span bridge for Washington, D.C., that will be one of the world's largest prestressed concrete cantilever-type bridges. Since the prototype bridge is symmetrical about the center of the 750-ft main span, only one-half of the bridge was modeled. The model was constructed in the same manner as anticipated for the prototype—segmental, cantilever type, post-tensioned in three directions. Sophisticated instrumentation measured loads, reactions, steel and concrete strains, deflections, and rotations. Test results show suitability of design and conformance with specifications. This report is also found on DVD021.
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Durability of Concrete in Sulfate-Rich Soils
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Item Code: RD097
Date of Publication: 1990
Price: $0.00
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Reports on an ongoing investigation of the sulfate resistance of concrete specimens in a Sacramento, California., soils test facility. Test variables in this phase included cement content, fly ash content, slag content, water-cement ratio, and coatings. This report illustrates the importance of using a low water-cement ratio. This report is also found on DVD021.
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Durability of Ternary Blended Cements in Bridge Applications
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Item Code: SN2754
Date of Publication: 2007
Price: $0.00
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The long-term performance of bridge components can be greatly influenced by the durability parameters including freeze-thaw and chloride permeability resistance. Both freeze-thaw resistance and chloride permeability resistance were tested along with the compressive strength of 24 high performance concrete (HPC) mixtures. The effects of binary and ternary blended HPC including silica fume and fly ash were tested with respect to freeze thaw resistance and chloride permeability. The study included observations of how water to binder ratio and curing time affected the pore structure development of fly ash and silica fume concretes when tested using the Rapid Chloride Permeability Test.
The results indicate that properly air entrained HPC is generally resistant to the effects of freezing and thawing as there was minimal degradation of the dynamic modulus of elasticity in all specimens tested. This thesis was developed as part of the educational requirements under a fellowship grant from PCA.
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Effect of Superstructure Properties on Concrete Bridge Deck Deterioration
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Item Code: SN2936
Date of Publication: 2006
Price: $0.00
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What this project endeavored to do was to employ an extensive literature review, a study of bridges in the field, and a computational finite element model, to synthesize a variety of issues that relate "steel vs. concrete" girder properties to the deterioration of bridge decks to help determine why decks supported on concrete girder perform better than similar decks supported on steel girders. Five key issues pertaining to the girder properties were explored, but they were evaluated and discussed for the most part, independent of one another, rendering any definite overall conclusions impossible (or at least irresponsible).
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Effects of High Performance Concrete on Corrosion of Reinforcement
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Item Code: SN2676
Date of Publication: 2005
Price: $0.00
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This project demonstrated that high performance concrete provides superior protection to steel in sound (uncracked) concrete than does ordinary portland cement concrete (OPCC). Even when subject to structural cracks in the range of 0.1 to 0.5 mm, the HPC provides additional protection to the steel, by limiting the area of steel participating in the corrosion process, for both the anodic and cathodic half cell components of the process. Furthermore, there appeared to be little difference in the behavior of the steel exposed to 0.1 mm and 0.3 mm wide cracks whereas a higher level of corrosion was observed in the specimens with 0.5 mm crack widths. This report is also found on DVD021.
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Evaluation of Super Water Reducers for Highway Applications
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Item Code: RD078
Date of Publication: 1981
Price: $0.00
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Report discusses performance of various super water reducers in mixtures typical of those used in pavements, bridge decks, and thin-bonded overlays. Reviews problems concerning slump loss, air entrainment, and use in central-mixing operations. This report is also found on DVD021.
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Fatigue Strength of High-Yield Reinforcing Bars
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Item Code: RD045
Date of Publication: 1976
Price: $0.00
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Report of investigation consisting of a literature review, an extensive experimental program, and a statistical analysis of test results from which a fatigue design provision for deformed reinforcing bars was developed. The study included 353 tests on reinforced concrete beams, each containing a single straight deformed bar. Tests covered major effects of stress range, minimum stress, bar diameter, type of specimen, grade of bar, and bar geometry. Stress range was the predominant factor influencing fatigue strength of reinforcing bars. This report is also found on DVD021.
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