Download or read book Improving Durability of Bridge Decks by Transverse Prestressing written by R. W. Poston and published by . This book was released on 1984 with total page 1274 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Durability of Prestressed Bridge Decks written by R. W. Poston and published by . This book was released on 1985 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Use of Innovative Concrete Mixes for Improved Constructability and Sustainability of Bridge Decks written by and published by . This book was released on 2013 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge deck crack surveys were performed on twelve bridges on US-59 south of Lawrence, Kansas, to determine the effects of mixture proportions, concrete properties, deck type, and girder type on the crack density of reinforced concrete bridge decks. Of the twelve decks surveyed, eight are supported by prestressed concrete girders and four are supported by steel girders. Four of the decks supported by prestressed girders are cast on partial-depth precast deck panels, two are monolithic with synthetic fibers, and two have overlays. Of the four decks supported by steel girders, two have silica fume overlays (SFO) and two are monolithic. One of two decks with a silica fume overlay contains synthetic fibers in the overlay. Following the surveys, crack maps were plotted and analyzed and cracking trends were observed. The results for the US-59 bridge decks are compared with crack densities obtained in a study of low-cracking high-performance concrete (LC-HPC) bridge decks. The monolithic concrete bridge decks supported by prestressed concrete girders within this study exhibit less cracking than decks supported by steel girders. At an age of approximately three and a half years, the US-59 monolithic decks supported by prestressed girders with deck panels are not displaying significant cracking; most of the cracks are short transverse cracks aligned with the joints between the deck panels. The US-59 decks supported by prestressed girders with overlays exhibit significantly more cracking than the decks on prestressed girders without overlays. Bridge decks supported by steel girders without overlays have slightly higher crack densities than the decks with overlays. No benefits of using fibers in either the overlay or deck have been observed in this study, the sample size, however, is small. An increase in crack density was observed with an increase in average concrete slump for decks supported by both prestressed and steel girders. Decks with deck panels supported by prestressed girders exhibited an increased crack density with an increase in paste content.

Download or read book Effect of Constituent Materials and Curing Methods on the Abrasion Resistance and Durability of High Performance Concrete for Pre cast Pre stressed Bridge Deck Slabs written by Shweta Keshari and published by . This book was released on 2010 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 of bridges by developing one or more materials systems for precast and pre-stressed bridge deck components that improve the studded tire wear (abrasion) resistance and durability of bridge decks. Degradation of the concrete bridge decks due to abrasion caused by the studded tires and accelerated corrosion of the reinforcing steel in the concrete often triggers costly, premature rehabilitation or replacement of these bridges. High performance concrete (HPC) can provide improved abrasion resistance, but is more costly than ordinary concrete and can exhibit early age cracking when used for cast-in-place concrete members, which can accelerate corrosion of embedded reinforcing steel. However, several studies have suggested that HPC developed for precast members offers a viable alternative to cast-in-place concrete deck slabs due in part to improved control of the curing process. The scope of this research was to develop one or more mixture designs for HPC that improve the durability and abrasion resistance of the bridge decks through careful selection and proper proportioning of the constituent materials and improved control of the curing process. The materials investigated in this research included silica fume, slag, and fly ash as partial replacement of Type I and Type III portland cement mixed with crushed aggregate and river gravel. Phase I of the study included development of 15 mixture designs incorporating various combinations of the materials. Mixtures were cast under controlled laboratory conditions and cured using a variety of methods. The results of tests conducted on the cured samples indicated that the mixture with silica fume and slag had greater strength than the mixture with silica fume and fly ash mixture, and that mixtures with crushed rock provided better abrasion resistance than those with river gravel. Results from the chloride ion penetration test for permeability indicated that mixtures cured in saturated lime water for 28 days exhibited reduced permeability in comparison to mixtures which were steam cured followed by ambient curing. Following phase I, a pilot study was undertaken to identify the best curing method to apply during production at precast yards to assist high early strength gain so that the concrete member can be removed from the casting bed in a matter of several hours as well as to facilitate high ultimate strength, improved abrasion resistance, and low permeability. The pilot study indicated the best curing method to be steam curing followed by application of a curing compound. Phase II of the research study included seven mix designs and focused on various levels of supplementary cementitious materials. It adopted the curing method suggested by the pilot study. Results from phase II indicated that slag was better in enhancing durability of the concrete than fly ash. Increasing the proportion of silica fume did not improve the properties of high performance concrete significantly. Some other interesting results indicated that compressive strength was inversely proportional to wear rate and chloride ion penetration. Wear rate was directly proportional to chloride ion penetration. There was no relationship between durability factor (freeze-thaw test) and compressive strength or chloride ion penetration. Two mixtures were identified as having significantly improved abrasion and permeability characteristics over the control mixture (ODOT bridge deck mixture). Both included slag and silica fume as supplementary cementitious materials as a partial replacement of portland cement and one did not contain an air entraining admixture.

Download or read book Post tensioning the Inverted t Bridge System for Improved Durability and Increased Span to depth Ratio written by Rim Nayal and published by . This book was released on 2007 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Possibly the most pressing need in highway construction today is the repair or replacement of existing bridges. Due to increased needs and growing traffic, in addition to aging and extensive use, more than 2000 bridges in Kansas alone need to be replaced during the next decade. The majority of these bridges has spans of 100 ft or less, and has relatively shallow profiles. It is becoming increasingly important to implement a standard method for replacement in which the process is expedited and accomplished in cost-effective manner. Requirements for design and construction of concrete bridges have drastically changed during recent years. A main change in design is live-load requirements. Nebraska inverted-T bridge system has gained increasing popularity for its lower weight compared to I-girder bridges. However, there are some limiting issues when using IT system in replacing existing CIP bridges. Implementation of a post-tensioned IT system, which is the focus of this research, is believed to be one excellent solution for the IT deficiencies. Post-tensioning is added by placing a draped, post-tensioning duct in the stems of the IT members. Post-tensioning will lead to a higher span-to-depth ratio than IT system, and will reduce the potential transverse cracks in the (CIP) deck. Finally, the undesired cambers of pretensioned beams will be reduced, because fewer initial prestressing will be needed. This study was intended to explore the behavior of the PT-IT system, identify major parameters that control and limit the design of this system, and investigate different construction scenarios. This was achieved by conducting an extensive parametric study. For that purpose, PT-IT analysis program was developed and written using C++ programming language. The program was used to analyze various post-tensioning procedures for the post-tensioned inverted-T system. A Visual Basic friendly interface was provided to simplify the data input process. The findings of this research included recommendation of construction scenario for PT-IT system, as well as examining different methods for estimating time-dependent restraining moments. Effect of different concrete strengths on the behavior of PT-IT system was also determined. Most importantly, the effect of timing on different construction stages was also evaluated and determined.

Download or read book Durability of Post tensioning Tendons written by fib Fédération internationale du béton and published by fib Fédération internationale du béton. This book was released on 2001-01-01 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: In some countries durability problems with post-tensioning tendons have in the past led to fairly restrictive regulations. Improvements to execution procedures have been developed since, and new or improved prestressing systems have been proposed, too. This development was, of course, subject of discussions in fib Commission 9 Reinforcing and Prestressing Materials and Sytems and in IABSE Working Commission 3 Concrete Structures. It was decided to organise a workshop with the aim to review the different aspects of the problems encountered and to discuss solutions available today. Keynote speakers from various countries were invited to contribute. Their papers are published in this bulletin, grouped together under the following themes: Inventory and condition (6 papers) Investigation and repair (5 papers) Technical progress (4 papers) Strategies for improvement (6 papers) Supported by the international federation for structural concrete fib, and the international association for bridge and structural engineering IABSE, the workshop took place on 15-16 November 2001 at Ghent University, celebrating the 75th anniversary of the Magnel Laboratory for Concrete Research, whose director also chaired the Scientific Committee and edited the bulletin. It needs to be emphasised that in the bulletin invited experts present their individual views. Although not yet discussed in any of the association's working bodies, the highly topical contents of the bulletin is believed to be of general interest to fib's members and to document a starting point for future work in this field. Therefore, the Council of fib agreed to exceptionally publish these papers within fib's series of Bulletins.

Download or read book Durability of Concrete Bridge Decks written by and published by . This book was released on 1967 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Performance Concrete Bridge Decks A Fast Track Implementation Study Volume 1 Structural Behavior written by Robert J. Frosch and published by Purdue University Press. This book was released on 2008-11-01 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transverse cracking of concrete bridge decks is problematic in numerous states. Cracking has been identified in the negative and positive moment regions of bridges and can appear shortly after opening the structure to live loads. To improve the service life of the bridge deck as well as decrease maintenance costs, changes to current construction practices in Indiana are being considered. A typical bridge deck was instrumented which incorporated the following: increased reinforcement amounts, decreasing reinforcement spacing, and high-performance, low-shrinkage concrete. The low shrinkage concrete was achieved using a ternary concrete mix. The objective of this research was to determine the performance, particularly in terms of transverse cracking and shrinkage, of a bridge incorporating design details meant to reduce cracking. Based on measurements from the bridge, it was determined that maximum tensile strains experienced in the concrete were not sufficient to initiate cracking. An on-site inspection was performed to confirm that cracking had not initiated. The data was analyzed and compared with the behavior of a similarly constructed bridge built with nearly identical reinforcing details, but with a more conventional concrete to evaluate the effect of the HPC. Based on this study, it was observed that full-depth transverse cracks did not occur in the structure and that the use of HPC lowered the magnitude of restrained shrinkage strains and resulting tensile stresses.

Download or read book Cause and Control of Transverse Cracking in Concrete Bridge Decks written by M. Ala Saadeghvaziri and published by . This book was released on 2002 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many concrete bridge decks develop transverse cracking and most of these cracks develop at early ages, some right after construction and some after the bridge has been opened to traffic for a period of time. Structural design factors have not been the subject of much research in the past and they were the main thrust of this research study. Using 2-D and 3-D linear and nonlinear finite element models many design factors such as girder stiffness, deck thickness, girder spacing, relative stiffness of deck to girder, amount of reinforcements, etc., were studied. The research study also included a comprehensive review of the existing literature as well as survey of 24 bridges in the state of New Jersey. Results of each research task are presented and discussed in detail. Furthermore, based on analytical results and literature review, the effect of various factors are quantified and specific recommendations for possible consideration in design are made.

Download or read book Field Verification of Bridge Deck Post tensioning written by and published by . This book was released on 1987 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of High Performance Concrete in Four Bridge Decks as Well as Prestressed Girders for Two Bridges written by V. Ramakrishnan and published by . This book was released on 2001 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Construction of Bridge Decks with Precast Prestressed Concrete Deck Planks written by Tessa H. Volle and published by . This book was released on 2002 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transverse Cracking of High Performance Concrete Bridge Decks After One Season Or Six to Eight Months written by and published by . This book was released on 2006 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cracking is a major problem with newly placed concrete decks. These decks tend to develop full depth, transverse cracks and partial depth longitudinal cracks within a few months of the concrete being placed. A literature review showed that several other states had experienced similar problems. A review of data from Ohio bridge decks showed weak correlations between deck cracking and slump, time of year when the deck was placed, shrinkage, chloride permeability and compressive strength, but there was no clear relationship between cracking and any of these properties. Data also suggested that using a coarse aggregate with an absorption> 1% may help mitigate deck cracking but will not always stop it. As part of this study, 3 bridge decks were instrumented. One was a standard class "S" concrete deck and the other two were high performance concrete. The class "S" deck showed only hairline cracking after 1 year, but transverse cracking occurred in the HPC decks. Instruments were placed in the decks to monitor strains. From the data, it appears that cracking is caused by several factors. High heat of hydration caused the plastic concrete to expand. When the concrete sets and cools, tensile stressed develop. Further tensile stresses develop through drying shrinkage. Restraining the deck against normal thermal movement contributes to additional tensile stress. Autogeneous shrinkage, where high heats of hydration cause water evaporation during hydration, and plastic shrinkage may cause more tensile stress. Recommendations for mitigating cracking include using lower cement contents, adding pozzolans and retarders, using slightly higher water/cement ratios, using larger aggregates, taking steps to limit shrinkage and eliminating restraints.

Download or read book The analysis of transverse prestressing effects in bridge decks written by Riyadh Ahmed Almustafa and published by . This book was released on 1983 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Evaluation of Full Depth Precast prestressed Concrete Bridge Deck Panels written by Mohsen A. Issa and published by . This book was released on 2002 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: A literature review concerning the objectives of the project was completed. A significant number of published papers, reports, etc., were examined to determine the effectiveness of full depth precast panels for bridge deck replacement. A detailed description of the experimental methodology was developed which includes design and fabrication of the panels and assembly of the bridge. The design and construction process was carried out in cooperation with the project Technical Review Panel. The major components of the bridge deck system were investigated. This includes the transverse joints and the different materials within the joint as well as composite action. The materials investigated within the joint were polymer concrete, non-shrink grout, and set-45 for the transverse joint. The transverse joints were subjected to direct shear tests, direct tension tests, and flexure tests. These tests exhibited the excellent behavior of the system in terms of strength and failure modes. Shear key tests were also conducted. The shear connection study focused on investigating the composite behavior of the system based on varying the number of shear studs within a respective pocket as well as varying the number of pockets within a respective panel. The results indicated that this shear connection is extremely efficient in rendering the system under full composite action. Finite element analysis was conducted to determine the behavior of the shear connection prior to initiation of the actual full scale tests. In addition, finite element analysis was also performed with respect to the transverse joint tests in an effort to determine the behavior of the joints prior to actual testing. The most significant phase of the project was testing a full-scale model. The bridge was assembled in accordance with the procedures developed as part of the study on full-depth precast panels and the results obtained through this research. The system proved its effectiveness in withstanding the applied loading that exceeded eight times the truck loading in addition to the maximum negative and positive moment application. Only hairline cracking was observed in the deck at the maximum applied load. Of most significance was the fact that full composite action was achieved between the precast panels and the steel supporting system, and the exceptional performance of the transverse joint between adjacent panels.

Download or read book Transverse Cracking in Newly Constructed Bridge Decks written by Paul D. Krauss and published by . This book was released on 1996 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Application of Transverse Prestressing for Bridge Decks written by and published by . This book was released on 1982 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: