Download or read book The Role of Magnesium in Concrete Deterioration written by Guoliang Gan and published by . This book was released on 1996 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Role of Magnesium in Concrete Deterioration written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Role of Magnesium in Concrete Deterioration written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Expansive Mineral Growth and Concrete Deterioration written by and published by . This book was released on 1997 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: A significant question is: What role does newly-formed expansive mineral growth play in the premature deterioration of concrete? These minerals (ettringite and brucite) are formed in cement paste as a result of chemical reactions involving cement and coarse/fine aggregate. Petrographic observations and SEM/EDAX analysis were conducted in order to determine chemical and mineralogical changes in the aggregate and cement paste of samples taken from Iowa concrete highways that showed premature deterioration. Mechanisms involved in deterioration were investigated. A second objective was to investigate whether deicer solutions exacerbate the formation of expansive minerals and concrete deterioration. Magnesium in deicer solutions causes the most severe paste deterioration by forming non-cementitious magnesium silicate hydrate and brucite. Chloride in deicer solutions promotes decalcification of paste and alters ettringite to chloroaluminate. Calcium magnesium acetate (CMA) and magnesium acetate (Mg-acetate) produce the most deleterious effects on concrete, with calcium acetate (Ca-acetate) being much less severe.

Download or read book Evaluation of Potential Concrete Deterioration Related to Magnesium Chloride MgCl2 Deicing Salts written by Ronald L. Kozikowski and published by . This book was released on 2007 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of magnesium chloride (MgCl2) as a deicing chemical has gained popularity due in part to its ability to significantly reduce the freezing temperature of precipitation. However, reports of concrete deterioration possibly linked to the use of MgCl2 salts have recently increased. A few laboratory studies have been conducted to determine the effects that MgCl2 has on concrete. Some studies report that the deterioration witnessed in the field is possibly the result of chemical attack on the concrete that weakens the paste structure. The findings from other studies vary greatly, as do some field reports that suggest DOT's have used the salt solution for as many as 10 years with no subsequent concrete damage. The purpose of this study was to provide further documentation on the effects that MgCl2 may have on concrete. Laboratory tests indicated the possible deterioration mechanism is not related to physical effects that are commonly associated with deicers and concrete distress such as freeze-thaw scaling and salt crystallization. Although little to no visual deterioration was observed in concrete test specimens, microscopic evaluation indicated minor chemical attack similar to other studies.

Download or read book Effects of Deicers on Concrete Deterioration written by and published by . This book was released on 2007 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete specimens were exposed to weekly cycles of wetting and drying in distilled water and in solutions of sodium chloride, calcium chloride, magnesium chloride, and calcium magnesium acetate with either a 6.04 molal ion concentration, equivalent in ion concentration to a 15% solution of NaCl, or a 1.06 molal ion concentration, equivalent in ion concentration to a 3% solution of NaCl, for periods of up to 95 weeks. Specimens were also exposed to air only. The effects of exposure were evaluated based on changes in the dynamic modulus of elasticity and the physical appearance of the specimens at the conclusion of the tests. Concretes exposed to distilled water and air show, respectively, an increase and a decrease in dynamic modulus of elasticity, due principally to changes in moisture content; overall, no negative impact on the concrete properties of these specimens is observed. At lower concentrations, sodium chloride and calcium chloride have a relatively small negative impact on the properties of concrete. At high concentrations, sodium chloride has a greater but still relatively small negative effect. At low concentrations, magnesium chloride and calcium magnesium acetate can cause measurable damage to concrete. At high concentrations, calcium chloride, magnesium chloride, and calcium magnesium acetate cause significant changes in concrete that result in loss of material and a reduction in stiffness and strength.

Download or read book Guidelines for the Selection of Snow and Ice Control Materials to Mitigate Environmental Impacts written by Levelton Consultants and published by Transportation Research Board. This book was released on 2007 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Significance of Tests and Properties of Concrete and Concrete making Materials written by Joseph F. Lamond and published by ASTM International. This book was released on 2006 with total page 661 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Significance of Tests and Properties of Concrete and Concrete making Materials written by Paul Klieger and published by ASTM International. This book was released on 1994 with total page 621 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Control of Concrete Deterioration Due to Trace Compounds in Deicers written by John Michael Pitt and published by . This book was released on 1992 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the research completed under the research contract entitled "Development of a Conductometric Test for Frost Resistance of Concrete" undertaken for the Iowa Highway Research Board. The objective of the project was to develop a test method which can be reasonably and rapidly performed in the laboratory and in the field to predict, with a high degree of certainty, the behavior of concrete subjected to the action of alternate freezing and thawing. The significance of the results obtained, and recommendations for use and the continued development of conductometric testing are presented in this final report. In this project the conductometric evaluation of concrete durability was explored with three different test methods. The test methods and procedures for each type of test as well as presentation of the results obtained and their significance are included in the body of the report. The three test methods were: (1) Conductometric evaluation of the resistance of concrete to rapid freezing and thawing, (2) Conductometric evaluation of the resistance of concrete to natural freezing and thawing, and (3) Conductometric evaluation of the pore size distribution of concrete and its correlation to concrete durability. The report also includes recommendations for the continued development of these test methods.

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 Concrete Durability written by Thomas Dyer and published by CRC Press. This book was released on 2014-05-01 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written specifically for the young professional and addressing a growing need for a long service life with minimal maintenance, Concrete Durability takes a whole new look at the whole-life performance of structures. This text examines physical and chemical issues that can threaten the durability of concrete. It explores available options for achiev

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 Expansive Mineral Growth and Concrete Deterioration written by Hyomin Lee and published by . This book was released on 1999 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: CMA and Mg-acetate produced the most deleterious effects on concrete, with Ca-acetate being much less aggressive. In order to use CMA as an alternative deicer and to prevent premature deterioration, it is recommended that it possess a high Ca/Mg ratio. Three types of commercially inhibitor chemicals, polyphosphonate, polyacrylate, and phosphate ester, were effective in reducing the formation of ettringite and also in reducing concrete expansion due to ettringite. Phosphonate inhibitors are the most effective among those inhibitors. These inhibitors are not effective in preventing formation of brucite and MSH from CMA and magnesium acetate solution.

Download or read book Concrete Deterioration written by Bryant Mather and published by . This book was released on 1967 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: The desirable objective is to produce concrete, for any particular use, at the lowest initial cost, that will undergo a limited and predictable degree of change with time so that it will not be found to have deteriorated until it no longer needs to serve its intended purposes. (Author).

Download or read book Mechanisms of Chemical Degradation of Cement based Systems written by K.L. Scrivener and published by CRC Press. This book was released on 1997-04-17 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deterioration of cement-based materials is a continuing problem, as it results in the substantial shortening of the lives of conventional concrete structures. The main costs result from poor performance and the need for early repair. With more advanced applications, where very long service lives are essential, such as the storage of nuclear waste, an understanding of the degradation processes in order to predict long term performance is very important. this book forms the proceedings of the latest Symposia at the Materials Research Society Autumn meeting in Boston.