Download or read book Investigating Various Test Methods for Assessing the Effect of Sulfate Attack on Concrete Properties written by Julie Ann Hartell and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The degradation mechanisms related to the numerous chemical and physical reactions associated with external sulphate attack are undeniably complicated and are difficult to assess in the field. This study compares various sodium sulphate exposure regimes by using novel testing procedures to assess the level of sulphate attack degradation throughout an extended exposure period. A total of four exposure regimes designed to simulate those encountered in practice were replicated to compare the differences between each transport mechanism: diffusion, diffusion combined with wet-dry cycling, evaporative wicking and wicking combined with wet-dry cycling. The laboratory specimens were exposed for periods of 3, 6, 12, 18 or 24 months to three different solutions; the ASTM standard solution (5% Na2SO4), a less concentrated version representative of severe field exposure (2% Na2SO4) and the control solution (lime-saturated). Once the end of the exposure term was reached, the specimens were subjected to a series of mechanical tests. This investigation evaluated the potential and reliability of various testing techniques to identify a sulphate related distress and to quantify its extent. Prior to destructive testing, ultrasonic pulse velocity was conducted; herein, two test frequencies were compared (54 kHz and 300 kHz). The change in tensile strength was measured in three different ways: an indirect splitting tensile test, a four point bending test and a direct gas pressure tension test. During the splitting tensile tests, acoustic emission monitoring was used to quantify and qualify damage progression under stress by locating the events in three dimensional space. The results demonstrate the sensitivity of each test in measuring the variance in mechanical properties related to the sulphate exposure types and offered insight into which experimental procedure is better suited for early sulphate damage detection. " --

Download or read book External Sulfate Attack of Concrete written by Federico Macias Aguayo Jr. and published by . This book was released on 2016 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sulfate attack of concrete is perhaps the least understood of the major durability mechanisms plaguing reinforced concrete infrastructures. Many studies have attempted to better understand the underlying mechanisms in which the various modes of deterioration by sulfate attack manifest; however, several controversies still exist. Moreover, ASTM C 1012 (2012), which is the most commonly referred standardized laboratory test method to determine sulfate resistance of blended portland cement mixtures, does not always link well to field performance and may take up to 18 months to complete. The research program presented in this dissertation investigates various issues pertaining to the mechanisms, testing methods, and factors influencing external sulfate attack. The primary focus of this research study was to investigate and propose a reliable, and innovative accelerated test method to evaluate the sulfate performance using concrete specimens. The research program was divided into the following four key components: (1) design a method that can obtain results within a reasonable timeframe (less than six months); (2) design a method that uses concrete specimens and thus links more closely to field performance; (3) develop a better understanding on the role and mechanisms of sulfate attack on concrete through a comprehensive research program including field and laboratory investigations; and (4) investigate the use of calcium sulfate (gypsum) used as an additive to mitigate the potential of sulfate attack in blended portland cement mixtures using high-calcium fly ash. The findings in this dissertation led to the development of a potential accelerated test method for determining sulfate resistance by vacuum impregnating concrete (or mortar) samples with sulfate solution to accelerate the ingress and onset of chemical reactions between the hydrated cement paste and sulfate ion (SO42-). The effects of binder type, water-to-cementitious ratio (w/cm), curing regime, sulfate type and concentration are examined. In comparison to the conventional ASTM C 1012 method, results showed a higher rate of expansion with significant distress observed in samples subjected to the accelerated test method and placed in a 5% Na2SO4 solution. Similar trends, but at a relatively lower expansion rate, were also observed in samples placed in a 0.89% Na2SO4 solution. Physical measurements, chemical analysis and microstructural studies were performed periodically on the specimens.

Download or read book External Sulphate Attack Field Aspects and Lab Tests written by Esperanza Menéndez and published by Springer Nature. This book was released on 2019-09-17 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume gathers contributions from the final workshop of the RILEM TC-251-SRT "Sulfate Resistance Testing" on External Sulfate Attack (TESA 2018), held on May 24-25, 2018 at IETcc-CSIC, Madrid, Spain. One of the Technical Committee’s main events, it addressed various aspects of external sulfate attack in concrete structures and test methods. The workshop promoted technical discussions and debates on ideas on these topics, with a focus on evaluating the resistance of concrete exposed to ESA. It also provided a forum for participants from around the globe to share their experiences and research on concrete structures affected by external sulfate attack and on test methods. The book discusses the latest advances in research related to ESA and new developments in test methods, and features real-world case studies of concrete structures affected by external sulfate attack in various countries. It also presents new studies linking field cases and lab tests, including 12 contributions on 3 main themes: mechanisms of alteration in external sulfate attack; field aspects of external sulfate attack; and testing to evaluate the resistance of concrete to external sulfate attack.

Download or read book Effects of C3A and Mineral Admixtures on the Sulfate Attack Using ASTM C 1012 written by N. Ahn and published by . This book was released on 2005 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are three major properties that influence concrete sulfate resistance: the chemistry of the Portland cement, the permeability of the concrete, and the chemistry and replacement level of mineral admixtures. In order to investigate the effect of those on the sulfate attack, the testing program involved testing several different mortar mixes using the standardized test, ASTM C 1012. Four different cements were evaluated including one Type I cement, two Type I-II cements, and one Type V cement. Mortar mixes were also made with mineral admixtures as each cement was combined with three different types of mineral admixtures. One Class F fly ash, one Class C fly ash, and one ground granulated blast furnace slag (GGBFS) was added in various % volumetric replacement levels. Expansion measurements were taken and investigated with expansion criteria recommended from past experience.

Download or read book Materials Science of Concrete written by Jacques Marchand and published by Wiley-American Ceramic Society. This book was released on 1999 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 18 papers grapple with new problems and old ones that remain unresolved concerning sulfate attack on concrete, not considered one of the most prevalent mechanisms of concrete deterioration, but one that has received much attention lately because of costly litigation against manufacturers, developers, and others. The topics include the role of ettringite in external sulfate attack, microstructural alterations in permeable concrete, assessing damage and predicting service life of venerable concrete, a marine environment, and the adequacy of standards. Annotation copyrighted by Book News, Inc., Portland, OR

Download or read book Sulfate Attack on Concrete written by J. Marchand and published by CRC Press. This book was released on 2001-10-11 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sulfate Attack on Concrete provides a comprehensive reference to this important subject. It covers: a short history of concrete deterioration due to sulfate attack, the origin of sulfates in concrete, the importance of appropriate concrete processing, forms and physical-chemical mechanisms of concrete deterioration due to sulfates, preventative mea

Download or read book Determination of Sulphates written by Agnes LaFoy Fay and published by . This book was released on 1905 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Concrete Technology 2 written by John Newman and published by Elsevier. This book was released on 2003-10-31 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the Institute of Concrete Technology's Advanced Concrete Technology Course, these four volumes are a comprehensive educational and reference resource for the concrete materials technologist. An expert international team of authors from research, academia and industry has been brought together to produce this unique series. Each volume deals with a different aspect of the subject: constituent materials, properties, processes and testing and quality. With worked examples, case studies and illustrations throughout, the books will be a key reference for the concrete specialist for years to come. - Expert international authorship ensures the series is authoritative - Case studies and worked examples help the reader apply their knowledge to practice - Comprehensive coverage of the subject gives the reader all the necessary reference material

Download or read book Mitigating Sulphate Attacks in Geotechnical Engineering written by Amin Chegenizadeh and published by Nova Science Publishers. This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A magnesium sulphate attack is one of the main issues that challenge civil engineering projects, in particular in coastal, landfill, and mining areas. This phenomenon reduces the stability of the structure and causes a complete failure for the system over time. Previous studies mainly focused on investigating the effects of magnesium sulphate attacks on concrete and from a structural point of view, and only a low number of studies investigated the effects of a magnesium sulphate attack on soil from a geotechnical point of view. The investigation on the effect of a magnesium sulphate attack is an important issue, particularly for stabilised soils that have a role in maintaining the integrity of foundations, slopes, embankments, etc. Portland cement (PC) is widely used in ground improvements and geotechnical engineering projects as an additive to improve the mechanical behaviour of soil. However, PC is effective to improve the engineering characteristics of soil; it is weak when exposed to the magnesium sulphate concentration. This book investigates the behaviour of different soils when treated with PC and after exposure to magnesium sulphate contamination. Also, the effect of some abundant materials in the environment such as carbon in the mechanical behaviour of stabilised soil has been investigated. The investigations have focused on shear strength and unconfined compressive strength (UCS) as two main important characteristics of stabilised soils, and they investigate their relevant characteristics. In this study, deep investigations have been conducted to figure out the behaviour of the magnesium sulphate concentration soils. However, additional research and study is required to procure a clear understanding of the interactions of the stabilised soils with magnesium sulphate concentration.

Download or read book Effects of Mix Design and Curing on Resistance of Mortar and Concrete to Physical Sulfate Attack written by Qian Wen Bi and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physical sulfate attack (PSA) is a serious mechanism of concrete deterioration spurred by temperature and humidity changes. Current standard tests assessing sulfate attack measure length change whereas PSA manifests in mass loss. A preliminary test using mass loss as an indicator was developed previously and used to evaluate the influence of mix design on mortar resistance against PSA. This study extended this research by: further assessing the viability of this test method, evaluating different wet curing durations, and extending the research to concretes. Prisms were stored in 30% by volume (24.5% by mass) sodium sulfate solution and cycled for 100 thermal cycles between 5 and 30 °C. Lowering the water-to-cementitious materials ratio and adding slag cement were found to increase resistance against PSA for mortars and concretes. The effect of wet curing is less conclusive due to interference from differential sulfate exposure occurring during initial cycling using this test method.

Download or read book An Investigative Study on Physical Sulfate Attack and Alkali silica Reaction Test Methods written by Travis Evans Lowe and published by . This book was released on 2011 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is unique in that it investigated two completely different forms of concrete deterioration: physical sulfate attack and the alkali-silica reaction (ASR). Research was undertaken to better understand physical sulfate attack in order to provide much needed guidance on how to prevent durable this form of deterioration. A testing regime was designed to evaluate and analyze different concrete mixtures with varying water to cementitious material ratios (w/cm), cement types (Type I and V), and use of supplementary cementing materials (SCMs) in accelerated laboratory exposure and outdoor exposure testing. The accelerated laboratory testing evaluated the performance of concrete cylinder segments fully submerged in 30% (by mass of solution) sodium sulfate solution exposed to a temperature and humidity cycle that would promote cycles of alternative conversion between anhydrous sodium sulfate (thenardite) and decahydrate sodium sulfate (mirabilite). In the outdoor exposure site, two different sized concrete cylinders per mixture proportion were partially submerged in 5% (33,000 ppm) sodium sulfate solution and exposed to alternative wetting and drying conditions, along with, temperature fluctuations that would promote conversion between thenardite (Na2SO4) and mirabilite (Na2SO4·10H2O). With regard to ASR test methods, it has been shown with past research that it is not possible to evaluate "job mixtures" or determine alkali thresholds using ASTM C 1293 (Concrete Prism Test) with evaluating aggregates and concrete mixture proportions for the susceptibility of ASR when testing job mixtures. The most commonly cited issue with the concrete prism test is excessive leaching of alkalis during the course of the test, which may not be a major issue when using the standard, high-alkali concrete mixtures as per ASTM C 1293 but is clearly an issue when testing lower-alkali concrete mixtures. For low-alkali mixtures, alkali leaching can reduce the internal alkali content below the threshold that triggers expansion for a given aggregate. A comprehensive study was initiated that evaluated various modifications to ASTM C 1293, with the intention of developing a testing regime better suited to testing "job mixes" and/or low-alkali concrete mixtures.

Download or read book Performance of Cement Based Materials in Aggressive Aqueous Environments written by Mark Alexander and published by Springer Science & Business Media. This book was released on 2012-12-18 with total page 471 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete and cement-based materials must operate in increasingly aggressive aqueous environments, which may be either natural or industrial. These materials may suffer degradation in which ion addition and/or ion exchange reactions occur, leading to a breakdown of the matrix microstructure and consequent weakening. Sometimes this degradation can be extremely rapid and serious such as in acidic environments, while in other cases degradation occurs over long periods. Consequences of material failure are usually severe – adversely affecting the health and well-being of human communities and disturbing ecological balances. There are also large direct costs of maintaining and replacing deteriorated infrastructure and indirect costs from loss of production during maintenance work, which place a great burden on society. The focus of this book is on addressing issues concerning performance of cement-based materials in aggressive aqueous environments , by way of this State-of-the-Art Report. The book represents the work of many well-known and respected authors who contributed chapters or parts of chapters. Four main themes were addressed: I. Nature and kinetics of degradation and deterioration mechanisms of cement-based materials in aggressive aqueous environments, II. Modelling of deterioration in such environments, III. Test methods to assess performance of cement-based materials in such environments, and which can be used to characterise and rate relative performance and inform long term predictions, IV. Engineering implications and consequences of deterioration in aggressive aqueous environments, and engineering approaches to the problem.

Download or read book A Water Resources Technical Publication written by United States. Bureau of Reclamation and published by . This book was released on 1963 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sulfate Amage to Concrete Floors on Sulfate Bearing Hardcore written by Building Research Establishment and published by Riba Publishing. This book was released on 2008-03 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers guidance on the damage to houses and other dwellings caused by sulphate attack to floor slabs resulting from use of sulphate-bearing hardcore. This document highlights several options for procedures for investigation, assessment and remedial measures. This document, prepared by the Building Research Establishment (BRE), provides authoritative guidance on the damage to houses and other dwellings caused by sulphate attack to floor slabs resulting from past use of sulphate-bearing hardcore. Written for local authorities, professionals and homeowners, this document highlights several options for procedures for investigation, assessment and remedial measures.

Download or read book Proceedings of the 2024 7th International Conference on Structural Engineering and Industrial Architecture ICSEIA 2024 written by Qingfei Gao and published by Springer Nature. This book was released on 2024 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fly Ash Increases Resistance of Concrete to Sulfate Attack written by James T Dikeou and published by . This book was released on 1975 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Test Methods to Evaluate the Sulfate Resistance of Concretes Containing Pozzolans written by Guillermo Castellanos G. and published by . This book was released on 1954 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: