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Use Of Lightweight Concrete For Reducing Cracks In Bridge Decks
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Book Synopsis Use of Lightweight Concrete for Reducing Cracks in Bridge Decks by :
Download or read book Use of Lightweight Concrete for Reducing Cracks in Bridge Decks written by and published by . This book was released on 2016 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cracks in bridge decks can be due to many factors related to environmental effects, chemical reactions, and structural loads. Careful selection of materials and mixture proportions can minimize cracking to some degree. To reduce cracking, shrinkage must be reduced; however, cracking also depends on other factors such as modulus of elasticity, creep, tensile strength, and restraint. A low modulus of elasticity and high creep help to minimize cracking. Lightweight concrete (LWC) has a lower modulus of elasticity, higher inelastic strains, a lower coefficient of thermal expansion, a more continuous contact zone between the aggregate and the paste, and more water in the pores of aggregates for continued internal curing when compared to normal weight concrete. These properties tend to reduce cracking in the concrete and are highly desirable in bridge decks. The Virginia Department of Transportation (VDOT) has been successfully using LWC in bridge structures. In most of these bridges, the coarse aggregate has been lightweight and the fine aggregate normal weight natural sand. The purpose of this study was to investigate the effectiveness of LWC in reducing cracks in bridge decks. Seven bridges from six VDOT districts were included in the study. Three bridge decks each were constructed in 2012 and 2013, and one was constructed in 2014. The results showed that bridge decks with fewer cracks than were typical of decks constructed with normal weight aggregate over the past 20 years or no cracks can be constructed with LWC mixtures. The study recommends that LWC with a maximum cementitious content of 650 lb/yd3 be used in VDOT bridge deck concrete mixtures.
Book Synopsis High-performance/high-strength Lightweight Concrete for Bridge Girders and Decks by : Thomas E. Cousins
Download or read book High-performance/high-strength Lightweight Concrete for Bridge Girders and Decks written by Thomas E. Cousins and published by Transportation Research Board. This book was released on 2013 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB's National Cooperative Highway Research Program (NCHRP) Report 733: High-Performance/High-Strength Lightweight Concrete for Bridge Girders and Decks presents proposed changes to the American Association of State Highway and Transportation Officials' Load and Resistance Factor Design (LRFD) bridge design and construction specifications to address the use of lightweight concrete in bridge girders and decks. The proposed specifications are designed to help highway agencies evaluate between comparable designs of lightweight and normal weight concrete bridge elements so that an agency's ultimate selection will yield the greatest economic benefit. The attachments contained in the research agency's final report provide elaborations and detail on several aspects of the research. Attachments A and B provide proposed changes to AASHTO LRFD bridge design and bridge construction specifications, respectively; these are included in the print and PDF version of the report. Attachments C through R are available for download below. Attachments C, D, and E contain a detailed literature review, survey results, and a literature summary and the approved work plan, respectively. Attachment C; Attachment D ; Attachment E; Attachments F through M provide details of the experimental program that were not able to be included in the body of this report. Attachment F; Attachment G; Attachment H; Attachment I; Attachment J; Attachment K; Attachment L; Attachment M. Attachments N through Q present design examples of bridges containing lightweight concrete and details of the parametric study. Attachment N; Attachment O; Attachment P; Attachment Q. Attachment R is a detailed reference list."--Publication information.
Book Synopsis Evaluation of Lightweight Concrete Mixtures for Bridge Deck and Prestressed Bridge Girder Applications by :
Download or read book Evaluation of Lightweight Concrete Mixtures for Bridge Deck and Prestressed Bridge Girder Applications written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As of 2005, 23% of the bridges in the Kansas infrastructure are classified as structurally deficient or functionally obsolete according to the ASCE Infrastructure Report Card (ASCE, 2008). One alternative to replacing the entire bridge structure is replacing only the superstructure with lightweight concrete. This option is more economical for city, county, and state governments alike. Replacing the superstructure with lightweight concrete can oftentimes allow the bridge rating to be upgraded to higher load capacities or higher traffic volumes. Furthermore, lightweight concrete can be used initially in a bridge deck to provide reduced weight and a lower modulus of elasticity, therefore lower cracking potential. The Kansas Department of Transportation is interested in the potential benefits of using lightweight aggregate concrete in Kansas bridge decks and prestressed bridge girders. This research project used three types of lightweight aggregate to develop lightweight concrete mixtures for a bridge deck and for prestressed bridge girders. Two of the lightweight aggregates were expanded shale obtained locally from the Buildex Company. One deposit was located in Marquette, Kansas, and the other in New Market, Missouri. The third lightweight aggregate source was expanded slate obtained from the Stalite Company in North Carolina. Aggregate properties including absorption, gradation, and L.A. Abrasion were evaluated. Over 150 lightweight concrete mixtures were created and tested and several mix design variables such as water-to-cement ratio, cement content, and coarse-to-fine aggregate ratio were evaluated. From these results, optimized bridge deck and optimized prestressed concrete mixtures were developed for each type of lightweight aggregate. Special concerns for lightweight aggregate concrete are addressed. These optimized concrete mixtures were then tested for KDOT acceptability standards for the concrete properties of compressive strength, tensile strength, modulus of elasticity, freeze-thaw resistance, permeability, alkali-silica reactivity, drying shrinkage, and autogenous shrinkage. All concrete mixtures performed satisfactorily according to KDOT standards. In addition, an internal curing effect due to the moisture content of the lightweight aggregate was observed during the autogenous shrinkage test.
Book Synopsis Development and Implementation of Lightweight Concrete Mixes for KDOT Bridge Applications by : Sarah Jo Grotheer
Download or read book Development and Implementation of Lightweight Concrete Mixes for KDOT Bridge Applications written by Sarah Jo Grotheer and published by . This book was released on 2009 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: As of 2005, 23% of the bridges in the Kansas infrastructure are classified as structurally deficient or functionally obsolete according to the ASCE Infrastructure Report Card (ASCE, 2008). One alternative to replacing the entire bridge structure is replacing only the superstructure with lightweight concrete. This option is more economical for city, county, and state governments alike. Replacing the superstructure with lightweight concrete can oftentimes allow the bridge rating to be upgraded to higher load capacities or higher traffic volumes. Furthermore, lightweight concrete can be used initially in a bridge deck to provide reduced weight and a lower modulus of elasticity, therefore lower cracking potential. The Kansas Department of Transportation is interested in the potential benefits of using lightweight aggregate concrete in Kansas bridge decks and prestressed bridge girders. This research project used three types of lightweight aggregate to develop lightweight concrete mixtures for a bridge deck and for prestressed bridge girders. Two of the lightweight aggregates were expanded shale obtained locally from the Buildex Company. One deposit was located in Marquette, Kansas, and the other in New Market, Missouri. The third lightweight aggregate source was expanded slate obtained from the Stalite Company in North Carolina. Aggregate properties including absorption, gradation, and L.A. Abrasion were evaluated. Over 150 lightweight concrete mixtures were created and tested and several mix design variables such as water-to-cement ratio, cement content, and coarse-to-fine aggregate ratio were evaluated. From these results, optimized bridge deck and optimized prestressed concrete mixtures were developed for each type of lightweight aggregate. Special concerns for lightweight aggregate concrete are addressed. These optimized concrete mixtures were then tested for KDOT acceptability standards for the concrete properties of compressive strength, tensile strength, modulus of elasticity, freeze-thaw resistance, permeability, alkali-silica reactivity, drying shrinkage, and autogenous shrinkage. All concrete mixtures performed satisfactorily according to KDOT standards. In addition, an internal curing effect due to the moisture content of the lightweight aggregate was observed during the autogenous shrinkage test.
Book Synopsis Behavior of Bridge with Internally Cured Concrete Deck Under Environmental and Truck Loading by : Waleed Khalid Hamid
Download or read book Behavior of Bridge with Internally Cured Concrete Deck Under Environmental and Truck Loading written by Waleed Khalid Hamid and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The long-term performance of a bridge deck depends on its resistance to bridge cracking. Most of these cracks are initiated at the early age. Early age cracking of bridge decks is a typical issue in the U.S. that reduces bridge service life. Therefore, internally cured concrete (ICC) has been used in some states to reduce or eliminate the development of cracks in reinforced concrete decks. In this study, the early age behavior of ICC deck and the effect of the internal curing on the long-term behavior of the bridge was measured and evaluated in the laboratory and field for newly adjacent constructed bridge, which were located on Route 271 in Mayfield, Ohio. Two different types of concrete mixtures were utilized for the decks: conventional concrete (CC) and internally cured concrete (ICC). Firstly, the ICC and CC mixtures were examined in the laboratory in terms of a mechanical properties test, a plastic shrinkage test, a free shrinkage test, and a restrained shrinkage test. Second, the field behavior of an ICC deck and an adjacent CC deck during their early age and long-term performance were evaluated. Also, the shrinkage development for both decks was examined during the very early age. Instrumentation was used to measure the concrete and reinforcement strains and the temperature in both bridges. The instrumentation and results for both bridges are discussed. Laboratory results indicated that using pre-wetted lightweight concrete in the concrete mixture led to decreased density, coefficient of thermal expansion, and free shrinkage strain, and increased tensile strength and cracking time of concrete compared to conventional concrete. In the field, from the early age test, it was observed that the time to develop concrete shrinkage was approximately 5-6 hours after casting the deck of the ICC and the CC.
Book Synopsis Extended Life Concrete Bridge Decks Utilizing Internal Curing to Reduce Cracking by : Xuhao Wang
Download or read book Extended Life Concrete Bridge Decks Utilizing Internal Curing to Reduce Cracking written by Xuhao Wang and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: With the ongoing concern about premature cracking of concrete bridge decks that reduces the service life of bridges and results in increased maintenance and replacement costs, this work aimed at assessing the benefits of using lightweight fine aggregate (LWFA) in concrete mixtures to assist the Ohio Department of Transportation (ODOT) in preparing a specification to increase the probability of achieving crack-free, long-lasting bridge decks. A laboratory testing program led to a recommended mix design for implementation on a bridge construction project in Ohio. The design included the use of 50% slag cement and LWFA for internal curing. Construction of two bridge decks involved a control using a conventional mix design and the other containing the recommended mixture. The decks were instrumented and load tested shortly after construction and inspected one year after placement. No differences in structural performance were noted, but there were far fewer cracks in the test deck compared to the control. A life-cycle cost analysis was also conducted and shown that the premium for the recommended mixture would be recovered in reduced maintenance over the life of the bridge.
Book Synopsis Evaluation of High Absorptive Materials to Improve Internal Curing of Low Permeability Concrete by : Norbert J. Delatte
Download or read book Evaluation of High Absorptive Materials to Improve Internal Curing of Low Permeability Concrete written by Norbert J. Delatte and published by . This book was released on 2007 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Early age cracking of bridge decks is a national problem, and may substantially reduce service lives and increase maintenance costs. Cracking occurs when the tensile stress exceeds the tensile strength of the concrete. This is a time-dependent phenomenon, since both the stress and strength change at early ages. Moisture loss increases stress (with increasing shrinkage) and impairs strength gain. Internal curing is one method that has been suggested to reduce early age bridge deck cracking, particularly of concretes with low water to cementitious materials (w/cm) ratios. Many state highway agencies have implemented high performance concrete (HPC) for bridge decks. The low permeability of HPC is used to protect reinforcing steel and prevent corrosion. However, if the concrete cracks, then the protection may be greatly diminished. Transverse cracks due to concrete shrinkage allow water and corrosive chemicals to quickly reach the reinforcing steel causing corrosion and shortening the lifespan of the bridge deck. Reducing shrinkage cracking has been the focus of recent research into mitigation strategies. One unintended consequence of the use of high performance concrete may be early-age cracking. Field studies have shown that, in some cases, high performance concrete bridge decks have cracked less than a year after placement. The use of internal curing to reduce autogenous shrinkage was investigated in this study. One method of internal curing was through the use of coarse aggregates with high absorption capacities. Another method discussed is the use of a partial replacement of the fine aggregate with a structural lightweight aggregate with a very high absorption capacity. Bridge deck cracking is also affected by the nominal maximum size coarse aggregate. The effect on shrinkage with increasing size is discussed. ODOT's District 12, located in Northeastern Ohio, found in an investigation of 116 HPC bridge decks placed between 1994 and 2001 that bridges with little or no cracking used coarse aggregate with an absorption> 1 %, while 75 % of bridges with unacceptable cracking used coarse aggregate with absorption 1 %. This report discusses the laboratory investigation of the field results to determine the better ways to prevent bridge deck cracking-- internal curing or paste reduction by using an aggregate blend. The laboratory investigation found that the strongest effect on cracking was due to the replacement of a small maximum size coarse aggregate with an optimized coarse aggregate gradation. Increasing the coarse aggregate absorption level from
Book Synopsis Mitigating Shrinkage Cracking of Concrete in Bridge Decks Through Internal Curing by : Daniel Robert Goad
Download or read book Mitigating Shrinkage Cracking of Concrete in Bridge Decks Through Internal Curing written by Daniel Robert Goad and published by . This book was released on 2013 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the need for durable, long lasting infrastructure increases, new methods and techniques are being explored to prolong the service life of roads and bridges. One method to reduce shrinkage and early age cracking in concrete is internal curing. Internal curing supplies water to concrete, using pre-wetted lightweight aggregate (LWA), as needed throughout the process of hydration to reduce self desiccation, which leads to cracking. This research project analyzed two types of coarse LWA, expanded clay and expanded shale. The mixtures were developed specifically for use in bridge decks and adhered to specifications of the Arkansas State Highway and Transportation Department (AHTD). The concrete mixtures contained LWA at rates of 0, 100, 200, and 300 lb/yd3. The research was divided into two phases. The first phase measured autogenous and drying shrinkage in both plastic and elastic states using embedded vibrating wire strain gages (VWSG) cast in concrete prisms. The expanded clay LWA mixtures, with the 300 lb. replacement rate yielding the best results, were most effective in reducing shrinkage. Compressive strength decreased as the amount of LWA included in the mixture increased. However, all mixtures surpassed the 28 day compressive strength specified by AHTD. The second phase of the research project measured plastic shrinkage cracking in thin concrete test slabs. Methods and materials were investigated to produce consistent plastic shrinkage surface cracks of the concrete slabs. The extent of plastic shrinkage that occurred was quantified by measuring the total crack area of the test slabs. Implementation of 300 lb. of expanded clay LWA did not reduce the crack lengths, but did reduce the average crack widths experienced by the test slabs due to plastic shrinkage.
Book Synopsis High-Performance Concrete Bridge Decks: A Fast-Track Implementation Study, Volume 1: Structural Behavior by : Robert J. Frosch
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.
Book Synopsis Reducing Cracks in Concrete Bridge Decks Using Shrinkage Reducing Admixture by : Harikrishnan Nair
Download or read book Reducing Cracks in Concrete Bridge Decks Using Shrinkage Reducing Admixture written by Harikrishnan Nair and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Restrained shrinkage cracking of concrete bridge decks creates a significant durability problem. Major admixture suppliers in the United States have introduced a new category of chemical admixtures called shrinkage reducing admixtures (SRAs). SRAs work by reducing the surface tension of pore water and thereby decreasing the capillary stress and shrinkage induced by drying. Several studies have reported that using SRAs in concrete mixtures is one of the most effective ways of reducing shrinkage cracking. The purpose of this study was to investigate the effectiveness of SRAs in reducing drying shrinkage in Virginia Department of Transportation (VDOT) concrete mixtures and thus reducing cracks in bridge decks. Nine bridges located in VDOT's Northern Virginia, Staunton, and Fredericksburg districts were selected for study. Three different SRA products were used. With the exception of one mixture, the maximum cementitious content was limited to 600 lb/yd3. Fresh and hardened concrete properties were determined for each mixture, and field placement details were documented. The results showed that low cementitious concrete with SRA was effective in minimizing bridge deck cracking. The study showed that bridges with fewer and narrower cracks or no cracks can be constructed and that proper construction practices are needed to reduce bridge deck cracking. The study recommends the use of SRA with a lower cementitious content in VDOT bridge deck concrete mixtures. A VDOT special provision was developed for the future use of SRA in concrete mixtures.
Book Synopsis Bridge Decks by : Ardavan Ardeshirilajimi
Download or read book Bridge Decks written by Ardavan Ardeshirilajimi and published by . This book was released on 2016 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Low Shrinkage Mix Designs to Reduce Early Cracking of Concrete Bridge Decks by : Eric Simonton
Download or read book Low Shrinkage Mix Designs to Reduce Early Cracking of Concrete Bridge Decks written by Eric Simonton and published by . This book was released on 2020 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract Shrinkage cracking is reducing the service life of concrete bridge decks in South Dakota due to premature deterioration. In this study, the effects of varying concrete mix design parameters on autogenous and drying shrinkage was observed. Tested mix design changes include aggregate type (limestone and quartzite) and gradations (ASTM C33, Tarantula Curve, and 0.45 Power Curve), supplementary cementitious materials (fly ash), cementitious content, water-to-cementitious ratio, internal curing using saturated lightweight aggregates (expanded shale), and shrinkage reducing admixtures. These changes were evaluated for their effect on the shrinkage of paste, mortar, and concrete as measured by ASTM C1698 (autogenous shrinkage) and ASTM C157 (drying shrinkage). Fresh property tests, compressive strength, and electrical resistivity measurements were performed on each mix as well. A survey of state Department of Transportations revealed the current state-of-the-art practices on shrinkage reduction in bridge decks, including the use of admixtures, internal curing agents, and external curing methods.
Book Synopsis Reducing Cracks in Concrete Bridge Decks Using Shrinkage Reducing by : Harikrishnan Nair
Download or read book Reducing Cracks in Concrete Bridge Decks Using Shrinkage Reducing written by Harikrishnan Nair and published by . This book was released on 2016 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Restrained shrinkage cracking of concrete bridge decks creates a significant durability problem. Major admixture suppliers in the United States have introduced a new category of chemical admixtures called shrinkage reducing admixtures (SRAs). SRAs work by reducing the surface tension of pore water and thereby decreasing the capillary stress and shrinkage induced by drying. Several studies have reported that using SRAs in concrete mixtures is one of the most effective ways of reducing shrinkage cracking. The purpose of this study was to investigate the effectiveness of SRAs in reducing drying shrinkage in Virginia Department of Transportation (VDOT) concrete mixtures and thus reducing cracks in bridge decks. Nine bridges located in VDOT Northern Virginia, Staunton, and Fredericksburg districts were selected for study. Three different SRA products were used. With the exception of one mixture, the maximum cementitious content was limited to 600 lb/yd3. Fresh and hardened concrete properties were determined for each mixture, and field placement details were documented. The results showed that low cementitious concrete with SRA was effective in minimizing bridge deck cracking. The study showed that bridges with fewer and narrower cracks or no cracks can be constructed and that proper construction practices are needed to reduce bridge deck cracking. The study recommends the use of SRA with a lower cementitious content in VDOT bridge deck concrete mixtures. A VDOT special provision was developed for the future use of SRA in concrete mixtures.
Book Synopsis Controlling Early-age Transverse Cracking in High Performance Concrete Bridge Decks by : Eric Ying Xian Liu
Download or read book Controlling Early-age Transverse Cracking in High Performance Concrete Bridge Decks written by Eric Ying Xian Liu and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Transverse Cracking of High Performance Concrete Bridge Decks After One Season Or Six to Eight Months by :
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.
Book Synopsis Study on Reduction of Shrinkage Cracks in Bridge Deck Concrete by : Rajesh Anumakonda
Download or read book Study on Reduction of Shrinkage Cracks in Bridge Deck Concrete written by Rajesh Anumakonda and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Shrinkage is an unavoidable property of concrete that can lead to cracking, thereby limiting the serviceability of concrete structures. Shrinkage cannot be eliminated but can be minimized. Shrinkage cracking can be a critical problem in concrete construction, especially for flat slab structures such as highway pavements, industrial slab-on-grade, for parking garages, and bridge decks. The primary objective of the research is to evaluate three practical methods to reduce shrinkage cracks in concrete for bridge deck applications. The three methods evaluated are: 1) use of optimized aggregate gradation concrete, 2) use of a new high performance concrete known as low-cracking high performance concrete (LC-HPC) and 3) the use of Fibra Shield Fibers to reduce plastic shrinkage cracking in concrete.
Book Synopsis Use of Sand Lightweight Concrete and All Lightweight Concrete by : H. Celik Ozyildirim
Download or read book Use of Sand Lightweight Concrete and All Lightweight Concrete written by H. Celik Ozyildirim and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lightweight concrete (LWC) has reduced density, enabling a reduced dead load compared to normal weight concrete, thus allowing longer spans, slender columns, fewer piers in new construction, and the use of existing substructures in rehabilitation projects. LWC in which both the coarse and fine aggregates are lightweight, called “All LWC,” has an even greater reduction in density than “Sand LWC,” where only the coarse aggregate is lightweight. LWC also has a low cracking potential at all ages mainly because of internal curing, a low modulus of elasticity, and a low coefficient of thermal expansion. Lightweight aggregates must be prewetted in order for these benefits to be achieved. This study investigated All LWC and Sand LWC in the laboratory for use in bridge structures. LWCs with varying total cementitious material contents, supplementary cementitious material, and water–cementitious material ratios had satisfactory strengths for use in bridge structures. Differences in compressive strength between air-cured and moist-cured specimens were smaller than with normal weight concretes, which was attributed to internal curing that provided moisture for the hydration reactions. The reduced elastic modulus obtained enables lower stresses for a given deformation, helping to reduce bridge deck cracking. LWC with fibers had high tensile strength and ductility, which can control cracking, including that related to loads.
