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 Effects of Deicing Salt Trace Compounds on Deterioration of Portland Cement Concrete written by John Michael Pitt and published by . This book was released on 1987 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research on the effects of calcium sulfate in halite on Portland cement durability.
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 Impact of Airport Pavement Deicing Products on Aircraft and Airfield Infrastructure written by Xianming Shi and published by Transportation Research Board. This book was released on 2008 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB's Airport Cooperative Research Program (ACRP) Synthesis 6: Impact of Airport Pavement Deicing Products on Aircraft and Airfield Infrastructure explores how airports chemically treat their airport pavements to mitigate snow and ice, and the chemicals used. The report also examines the effects of pavement deicing products on aircraft and airfield infrastructure, and highlights knowledge gaps in the subject"--Publisher's description.
Download or read book The Deleterious Chemical Effects of Concentrated Deicing Solutions on Portland Cement Concrete written by Lawrence Sutter and published by . This book was released on 2008 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research project investigated the effects of concentrated brines of magnesium chloride, calcium chloride, sodium chloride, and calcium magnesium acetate on portland cement concrete.
Download or read book Effect of Deicing Chemicals on the Strength and Deterioration of Concrete written by Ccee Chan and published by . This book was released on 2007 with total page 274 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 and published by . This book was released on 1988 with total page 37 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 Control of concrete deterioration due to trace compounds in deicers written by and published by . This book was released on 1989 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 Sustainable Winter Road Operations written by Xianming Shi and published by John Wiley & Sons. This book was released on 2018-08-27 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first and only comprehensive guide to best practices in winter road operations Winter maintenance operations are essential to ensure the safety, mobility, and productivity of transportation systems, especially in cold-weather climates, and responsible agencies are continually challenged to provide a high level of service in a fiscally and environmentally responsible manner. Sustainable Winter Road Operations bridges the knowledge gaps, providing the first up-to-date, authoritative, single-source overview and guide to best practices in winter road operations that considers the triple bottom line of sustainability. With contributions from experts in the field from around the world, this book takes a holistic approach to the subject. The authors address the many negative impacts on regional economies and the environment of poorly planned and inadequate winter road operations, and they make a strong case for the myriad benefits of environmentally sustainable concepts and practices. Best practice applications of materials, processes, equipment, and associated technologies and how they can improve the effectiveness and efficiency of winter operations, optimize materials usage, and minimize cost, corrosion, and environmental impacts are all covered in depth. Provides the first up-to-date, authoritative and comprehensive overview of best practices in sustainable winter road operations currently in use around the world Covers materials, processes, equipment, and associated technologies for sustainable winter road operations Brings together contributions by an international all-star team of experts with extensive experience in designing, implementing, and managing sustainable winter road operations Designed to bring professionals involved in transportation and highway maintenance and control up to speed with current best practice Sustainable Winter Road Operations is essential reading for maintenance professionals dealing with snow and ice control operations on highways, motorways and local roads. It is a valuable source of information and guidance for decision makers, researchers, and engineers in transportation engineering involved in transportation and highway maintenance. And it is an ideal textbook for advanced-level courses in transportation engineering.
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 Investigation of the Damaging Effects of Exposure to Deicing Chemicals on Portland Cement Materials written by Daniel Erik Nelsen and published by . This book was released on 2003 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study was designed to partially replicate winter environments and to empirically observe the damaging potential of each of the five different deicing chemicals to Portland cement materials in winter environments. These chemicals were sodium chloride, calcium chloride, potassium acetate, and Geomelt. Paste and concrete samples were exposed after 7 days optimal curing to one of these chemicals in either wet-dry or freeze-thaw simulated environments. Physical deterioration of these samples was analyzed measuring unit weight loss, change in compressive strength, and visual scaling. Chemical deterioration was investigated using x-ray diffraction (XRD) to identify formation of new phases, scanning electron microscopy (SEM) to observe microstructural changes, and ion penetration testing (IPT) to determine the magnitude of Cl−, Na, and K+ ions with varying depth within deicer-exposed concrete samples. CaCl2 solutions caused the most damage to both paste and concrete. In freeze-thaw conditions, concrete strength decreased by more than 60%. Geomelt, an acidic solution derived from agricultural waste, caused consistent mass loss in nearly all environments. Sodium chloride and potassium acetate were relatively benign in causing physical deterioration. The use of a corrosion inhibitor in one of the CaCl2 solutions delayed the onset of damage in freeze-thaw samples, but may not have been effective at reducing the ultimate damage to CaCl2-exposed samples. XRD identified the occurrence of two new diffraction peaks in CaCl2-exposed samples occurring at approximately 8.35A and 4.00A. No other significant chemical phase changes were identified. SEM revealed considerable precipitation of Cl− and Ca2+ ions around void perimeters and along cracks surfaces in CaCl2-exposed samples and to a lesser degree on NaCl-exposed samples. IPT identified Cl− and K+ concentrations greater than 4 times that of control samples at depths exceeding 1.2 inches in samples exposed to chloride deicers and potassium acetate, respectively. These high ionic concentrations may exacerbate chemical interaction, crystal growth, or other phenomena like corrosion of reinforcement or alkali-silica reactions.
Download or read book Effect of Chloride based Deicers on Reinforced Concrete Structures written by and published by . This book was released on 2010 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation Into Possible Methods to Screen for Chemical Degradation of Pervious Concrete Due to Common Deicers written by Trace William Sendele and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigating the Deterioration of Concrete Exposed to Potassium Acetate Deicer Solution written by Sean Hayman and published by . This book was released on 2014 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation examines the effect of potassium acetate (KAc) on concretes, mortars and pastes. The Colorado Springs Gazette (Colwell, 2006) first reported damage to the Colorado Springs Airport that alleged the use of K.Ac as a runway deicer accelerated alkali-silica reaction (ASR). Studies conducted by Rangaraju et al. (2007a), and Giebson et al. (2010) have focused mostly on K.Ac exacerbating ASR. This experimental study examined the effect of the concentration and type of solution, effect of exposure temperature, effect of sample size, effect of aggregate type, and effect of concrete compositions on the nature of the deterioration. Experiments were also conducted to examine the effect of K.Ac deicer on concrete containing alkali-silica reactive aggregates. The main testing however was completed on concretes and mortars with nonreactive aggregate, and pastes with the aim of elucidating the mechanism(s) or chemical reaction(s) responsible for the (non-ASR-related) deterioration previously observed in laboratory studies. With the use of techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM) a chemical reaction between the K.Ac deicer solution and ettringite was observed to have occurred in paste and mortar samples. K.Ac reacted with ettringite (C3A •3CSH2 •H32) to form arcanite (K2S04) and a calciumaluminate phase (possibly C4AH19). Testing was also conducted to find why there was excessive damage observed in pastes, mortars, and concretes in laboratory studies, yet very little damage has been seen in field studies. This testing concluded that the lack of penetration of KAc into concrete exposed to low temperatures is the main reason little damage has been seen in the field. Concrete that has not been cracked due to ASR is very resistant to the penetration of KAc when KAc solution is only applied during cold temperatures. The results show that if a pavement has been constructed with a non-reactive aggregate and the anti-icing/deicer solution is only applied when the temperature is near freezing or below then little significant damage attributed to KAc occurs.
Download or read book The Deleterious Chemical Effects of Concentrated Deicing Solutions on Portland Cement Concrete written by Michigan Tech Transportation Institute and published by . This book was released on 2008 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research project investigated the effects of concentrated brines of magnesium chloride, calcium chloride, sodium chloride, and calcium magnesium acetate on Portland cement concrete. Although known to be effective at deicing and anti-icing, the deleterious effects these chemicals may have on concrete have not been well documented. As a result of this research, it was determined that there is significant evidence that magnesium chloride and calcium chloride chemically interact with hardened Portland cement paste in concrete resulting in expansive cracking, increased permeability, and a significant loss in compressive strength. Although the same effects were not seen with sodium chloride brines, it was shown that sodium chloride brines have the highest rate of ingress into hardened concrete. This latter fact is significant with respect to corrosion of embedded steel. The mechanism for attack of hardened cement paste varies with deicer chemical but in general, a chemical reaction between chlorides and cement hydration products results in the dissolution of the hardened cement paste and formation of oxychloride phases, which are expansive. The chemical attack of the hardened cement paste is significantly reduced if supplementary cementitious materials are included in the concrete mixture. Both coal fly ash and ground granulated blast furnace slag were found to be effective at mitigating the chemical attack caused by the deicers tested. In the tests performed, ground granulated blast furnace slag performed better as a mitigation strategy as compared to coal fly ash. Additionally, siloxane and silane sealants were effective at slowing the ingress of deicing chemicals into the concrete and thereby reducing the observed distress. In general, the siloxane sealant appeared to be more effective than the silane, but both were effective and should be considered as a maintenance strategy.
