Serious deterioration of concrete usually occurs under the influence of both sea water and frost action in cold regions. In order to clarify the connection between pore structure and frost behavior of concrete surface as affected by sea water and freezing-thawing action, three series were carried out using small mortar and cement paste specimens. The first one was to investigate the effects of sea water on pore structure by means of mercury-intrusion porosity meter; the second one was to investigate the effects of sea water on products by means of X-ray diffraction; and the last one was to investigate the effects of sea water on freezable water by means of differential scanning calorimetry. Results obtained show that specimens immersed in sea water have many pores ranging in size of several hundred nm to thousand nm, and contain much more freezable water than those immersed in fresh water. When concrete is affected by both sea water and freezing and thawing action, the number of medium-size pores (100 nm to 1000 nm) and the amount of freezable water increase. There is good correlation between the total pore volume and the amount of freezable water. Accordingly, it is considered that marine concrete in cold regions deteriorates because the pore structure near the exposure surface becomes more porous and the amount of freezable water increases.
{"title":"Effect of Sea Water on Frost Damage to Mortar and Cement Paste","authors":"X. Wang, K. Ayuta","doi":"10.14359/10605","DOIUrl":"https://doi.org/10.14359/10605","url":null,"abstract":"Serious deterioration of concrete usually occurs under the influence of both sea water and frost action in cold regions. In order to clarify the connection between pore structure and frost behavior of concrete surface as affected by sea water and freezing-thawing action, three series were carried out using small mortar and cement paste specimens. The first one was to investigate the effects of sea water on pore structure by means of mercury-intrusion porosity meter; the second one was to investigate the effects of sea water on products by means of X-ray diffraction; and the last one was to investigate the effects of sea water on freezable water by means of differential scanning calorimetry. Results obtained show that specimens immersed in sea water have many pores ranging in size of several hundred nm to thousand nm, and contain much more freezable water than those immersed in fresh water. When concrete is affected by both sea water and freezing and thawing action, the number of medium-size pores (100 nm to 1000 nm) and the amount of freezable water increase. There is good correlation between the total pore volume and the amount of freezable water. Accordingly, it is considered that marine concrete in cold regions deteriorates because the pore structure near the exposure surface becomes more porous and the amount of freezable water increases.","PeriodicalId":184301,"journal":{"name":"\"SP-200: Fifth CANMET/ACI Conference on Recent Advances in Concrete Technology-Proceeding, Fifth International Conference\"","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114185383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High strength concrete mixtures containing 10% metakaolin replacement and 10% metakaolin addition, water/cementitious material ratio of 0.3 and 1% superplasticizer were studied. Similar mixtures incorporating silica fume were also prepared. The effect of mineral admixtures on the fresh and hardened properties of concrete was investigated. Mixtures with mineral admixture exhibited lower workability, less bleeding, and slightly lower air content. Metakaolin resulted in a higher loss of workability compared with silica fume. Mixtures incorporating mineral admixture developed greater compressive strength and elastic modulus at all ages. The enhancement was more pronounced at early ages and in the addition mixtures. The study concludes that the performance of metakaolin is equivalent to silica fume in terms of contribution to the enhancement of strength and elastic modulus. The metakaolin addition mixture attained 70% and 50% strength improvement while the metakaolin replacement mixture achieved 67% and 39% strength increment at the respective ages of 3 and 28 days.
{"title":"Effect of Incorporating Metakaolin on Fresh and Hardened Properties of Concrete","authors":"H. A. Razak, H. Wong","doi":"10.14359/10586","DOIUrl":"https://doi.org/10.14359/10586","url":null,"abstract":"High strength concrete mixtures containing 10% metakaolin replacement and 10% metakaolin addition, water/cementitious material ratio of 0.3 and 1% superplasticizer were studied. Similar mixtures incorporating silica fume were also prepared. The effect of mineral admixtures on the fresh and hardened properties of concrete was investigated. Mixtures with mineral admixture exhibited lower workability, less bleeding, and slightly lower air content. Metakaolin resulted in a higher loss of workability compared with silica fume. Mixtures incorporating mineral admixture developed greater compressive strength and elastic modulus at all ages. The enhancement was more pronounced at early ages and in the addition mixtures. The study concludes that the performance of metakaolin is equivalent to silica fume in terms of contribution to the enhancement of strength and elastic modulus. The metakaolin addition mixture attained 70% and 50% strength improvement while the metakaolin replacement mixture achieved 67% and 39% strength increment at the respective ages of 3 and 28 days.","PeriodicalId":184301,"journal":{"name":"\"SP-200: Fifth CANMET/ACI Conference on Recent Advances in Concrete Technology-Proceeding, Fifth International Conference\"","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125043066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The use of recycled-aggregate concrete is increasing faster than the development of appropriate design recommendations. This paper reports limited experimental data on the shear capacity of reinforced concrete beams recycled-aggregate. Twelve beams were tested to determine their diagonal cracking and ultimate shear capacities. The variables in the test program were shear-span/depth ratio a/d = 1.5, 2.0, 3.0 and 4.0; aggregate types; and shear reinforcement ratio = 0, 0.089, 0.244, 0.507, and 0.823 percent. Six of the test beams had no web reinforcement and the other six had web reinforcement along the entire length of the beam. Test results indicate that the ACI Building Code predictions of Eq. (11-3) and (11-5) for recycled aggregate concretes are unconservative for beams with a tensile steel ratio of 1.11% and a/d ratios greater than 3.0.
{"title":"Shear Capacity of Reinforced Concrete Beams Made with Recycled-Aggregate","authors":"B. Han, H. Yun, S. Chung","doi":"10.14359/10598","DOIUrl":"https://doi.org/10.14359/10598","url":null,"abstract":"The use of recycled-aggregate concrete is increasing faster than the development of appropriate design recommendations. This paper reports limited experimental data on the shear capacity of reinforced concrete beams recycled-aggregate. Twelve beams were tested to determine their diagonal cracking and ultimate shear capacities. The variables in the test program were shear-span/depth ratio a/d = 1.5, 2.0, 3.0 and 4.0; aggregate types; and shear reinforcement ratio = 0, 0.089, 0.244, 0.507, and 0.823 percent. Six of the test beams had no web reinforcement and the other six had web reinforcement along the entire length of the beam. Test results indicate that the ACI Building Code predictions of Eq. (11-3) and (11-5) for recycled aggregate concretes are unconservative for beams with a tensile steel ratio of 1.11% and a/d ratios greater than 3.0.","PeriodicalId":184301,"journal":{"name":"\"SP-200: Fifth CANMET/ACI Conference on Recent Advances in Concrete Technology-Proceeding, Fifth International Conference\"","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133798562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In Japan, it has been predicted that enormous quantities of demolished concrete will be produced in the future. Therefore, a great deal of research is being conducted to find ways to recycle this demolished concrete as concrete aggregate. However, because the characteristics of the original concrete are not well known in many cases, the results are also not clear. Moreover, the recycling of the cement in concrete is also necessary from the standpoint of resolving global environmental problems and achieving sustainable development. This paper describes the properties of the concrete made with recycled aggregates from the original concrete of known quality and the recycling of the cement in concrete as the approach that should be taken in the 21st Century.
{"title":"Recycling of Demolished Concrete","authors":"S. Nagataki, K. lida","doi":"10.14359/10568","DOIUrl":"https://doi.org/10.14359/10568","url":null,"abstract":"In Japan, it has been predicted that enormous quantities of demolished concrete will be produced in the future. Therefore, a great deal of research is being conducted to find ways to recycle this demolished concrete as concrete aggregate. However, because the characteristics of the original concrete are not well known in many cases, the results are also not clear. Moreover, the recycling of the cement in concrete is also necessary from the standpoint of resolving global environmental problems and achieving sustainable development. This paper describes the properties of the concrete made with recycled aggregates from the original concrete of known quality and the recycling of the cement in concrete as the approach that should be taken in the 21st Century.","PeriodicalId":184301,"journal":{"name":"\"SP-200: Fifth CANMET/ACI Conference on Recent Advances in Concrete Technology-Proceeding, Fifth International Conference\"","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115223779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Clemmens, P. Depuydt, H. Justnes, D. Gemert, E. J. Sellevold
The influence of a number of calcium salts on the total chemical shrinkage (used as a measure of cement hydration) of different portland cement pastes was followed during the first 48 hours. All calcium salts (acetate, chloride, formate, nitrate and nitrite) were added in an equimolar dosage of Ca2+ corresponding to 1.5% calcium nitrate by cement weight. An automatic Vicat-apparatus was used to monitor the setting time of the cement pastes. Experiments conducted at 5 degrees C, 13 degrees C and 23 degrees C revealed that calcium nitrate was the most effective set accelerator at lower temperatures and even more effective than calcium chloride at the lowest temperature. The anions of the different calcium salts were also found to influence the setting and the efficiency of each accelerator strongly depended on the cement types.
{"title":"Influence of Setting Accelerators on Chemical Shrinkage of Portland Cement","authors":"F. Clemmens, P. Depuydt, H. Justnes, D. Gemert, E. J. Sellevold","doi":"10.14359/10582","DOIUrl":"https://doi.org/10.14359/10582","url":null,"abstract":"The influence of a number of calcium salts on the total chemical shrinkage (used as a measure of cement hydration) of different portland cement pastes was followed during the first 48 hours. All calcium salts (acetate, chloride, formate, nitrate and nitrite) were added in an equimolar dosage of Ca2+ corresponding to 1.5% calcium nitrate by cement weight. An automatic Vicat-apparatus was used to monitor the setting time of the cement pastes. Experiments conducted at 5 degrees C, 13 degrees C and 23 degrees C revealed that calcium nitrate was the most effective set accelerator at lower temperatures and even more effective than calcium chloride at the lowest temperature. The anions of the different calcium salts were also found to influence the setting and the efficiency of each accelerator strongly depended on the cement types.","PeriodicalId":184301,"journal":{"name":"\"SP-200: Fifth CANMET/ACI Conference on Recent Advances in Concrete Technology-Proceeding, Fifth International Conference\"","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127333546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To achieve durable repairs, it is usually necessary to ensure adequate bond between the repair and the existing concrete substrate. Tensile bond tests are being increasingly used for quality control/quality assurance testing. However, there has been little standardization of test methods. Consequently, a total of 266 partial-depth cores in 77 experimental repairs were tested to evaluate the effect of material properties and environmental conditions on the bond between nine repair materials and a common concrete substrate. Three pull-off testing devices were used to determine bond strengths for each of the experimental repairs. In addition, the testing devices themselves were evaluated by analyzing the magnitude and relative precision of the pull-off strengths, modes of failure, and ease of use in an effort to identify a reliable and practical device for determining in situ tensile bond. The optimum depth of core drilling into the existing substrate was determined by comparing theoretical finite element analyses of failure stress and location with measured test results.
{"title":"Evaluation of Procedures for In Situ Tensile Bond Testing of Concrete Repairs","authors":"J. E. McDonald, A. Vaysburd","doi":"10.14359/10575","DOIUrl":"https://doi.org/10.14359/10575","url":null,"abstract":"To achieve durable repairs, it is usually necessary to ensure adequate bond between the repair and the existing concrete substrate. Tensile bond tests are being increasingly used for quality control/quality assurance testing. However, there has been little standardization of test methods. Consequently, a total of 266 partial-depth cores in 77 experimental repairs were tested to evaluate the effect of material properties and environmental conditions on the bond between nine repair materials and a common concrete substrate. Three pull-off testing devices were used to determine bond strengths for each of the experimental repairs. In addition, the testing devices themselves were evaluated by analyzing the magnitude and relative precision of the pull-off strengths, modes of failure, and ease of use in an effort to identify a reliable and practical device for determining in situ tensile bond. The optimum depth of core drilling into the existing substrate was determined by comparing theoretical finite element analyses of failure stress and location with measured test results.","PeriodicalId":184301,"journal":{"name":"\"SP-200: Fifth CANMET/ACI Conference on Recent Advances in Concrete Technology-Proceeding, Fifth International Conference\"","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130718742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High dosages of lignosulphonates or super-plasticizing are prohibited by the simultaneous setting retardation. However, the set retardation of lignosulphonates can be counteracted by calcium nitrate without destroying the rheology. Thus, such combinations can be cost-effective alternatives to super-plasticizers. The effect of different calcium nitrate dosages on 5 different lignosulphonates is documented by Fann viscosity, flow resistance and setting time on two different cement pastes. It has also been shown that calcium nitrate is capable of counteracting the effect of strong setting retarders like citric acid, etc. Another application can thus be over-retardation of concrete for long transport from the concrete ready mix plant, followed by activation by adding calcium nitrate to the revolving drum of the concrete truck when arriving at, or being close to, the construction site.
{"title":"Counteracting Retardation of Cement Setting By Other Admixtures with Calcium Nitrate","authors":"H. Justnes, B. G. Petersen","doi":"10.14359/10570","DOIUrl":"https://doi.org/10.14359/10570","url":null,"abstract":"High dosages of lignosulphonates or super-plasticizing are prohibited by the simultaneous setting retardation. However, the set retardation of lignosulphonates can be counteracted by calcium nitrate without destroying the rheology. Thus, such combinations can be cost-effective alternatives to super-plasticizers. The effect of different calcium nitrate dosages on 5 different lignosulphonates is documented by Fann viscosity, flow resistance and setting time on two different cement pastes. It has also been shown that calcium nitrate is capable of counteracting the effect of strong setting retarders like citric acid, etc. Another application can thus be over-retardation of concrete for long transport from the concrete ready mix plant, followed by activation by adding calcium nitrate to the revolving drum of the concrete truck when arriving at, or being close to, the construction site.","PeriodicalId":184301,"journal":{"name":"\"SP-200: Fifth CANMET/ACI Conference on Recent Advances in Concrete Technology-Proceeding, Fifth International Conference\"","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126728896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The investigation presented in this study shows an example of the improvements of fly ash fineness achieved by a physical process, air-classification and a mechanical process, grinding. To make high-performance concrete, three different types of fly ash namely, original, air-classified, and ground fly ash, with different finenesses was used as cement replacement. The percentage replacement of cement by each type of fly ash was used as 0, 10, 15 and 20% by weight of cementing materials. Finally, the results were compared with silica fume concrete. The results showed that substitution of part of the cement with original or classified fly ash produces concrete mixtures with greater workability than the control as measured by slump and slump-flow. On the contrary, it was found that the ground fly ash, having more or less the same degree of fineness as classified fly ash resulted in a lower workability due to the loss of its spherical shape and lubricant effect. The inclusion of original fly ash reduced the early strength and this reduction was more significant with the increase of percentage replacements. Classified and ground fly ash improved the early strength. The long-term strength development of classified and ground fly ash concrete was found to be considerably higher than that of control concrete for all the percentage replacements.
{"title":"Effects of Ground and Classified Fly Ash on Properties of High-Performance Concrete","authors":"M. K. H. Patoary, P. Nimityongskul","doi":"10.14359/10583","DOIUrl":"https://doi.org/10.14359/10583","url":null,"abstract":"The investigation presented in this study shows an example of the improvements of fly ash fineness achieved by a physical process, air-classification and a mechanical process, grinding. To make high-performance concrete, three different types of fly ash namely, original, air-classified, and ground fly ash, with different finenesses was used as cement replacement. The percentage replacement of cement by each type of fly ash was used as 0, 10, 15 and 20% by weight of cementing materials. Finally, the results were compared with silica fume concrete. The results showed that substitution of part of the cement with original or classified fly ash produces concrete mixtures with greater workability than the control as measured by slump and slump-flow. On the contrary, it was found that the ground fly ash, having more or less the same degree of fineness as classified fly ash resulted in a lower workability due to the loss of its spherical shape and lubricant effect. The inclusion of original fly ash reduced the early strength and this reduction was more significant with the increase of percentage replacements. Classified and ground fly ash improved the early strength. The long-term strength development of classified and ground fly ash concrete was found to be considerably higher than that of control concrete for all the percentage replacements.","PeriodicalId":184301,"journal":{"name":"\"SP-200: Fifth CANMET/ACI Conference on Recent Advances in Concrete Technology-Proceeding, Fifth International Conference\"","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115822810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The purpose of this paper is to determine the effect of mechanical loading on the transport properties of concrete. The test specimen (B1CL) used for chloride measurement, was a three-meter long reinforced beam kept in a loading state, in a confined salt fog (35 g/l of NaCl) for fourteen years. Because of corrosion of reinforcement, the characterization of mechanical loading was made on another old beam (B1T) cast at the same time but stored in a non-aggressive environment. The measurement of tensile concrete strains using strain gauges showed two parts in the bottom of the beam: the first one is characterized by an elastic behavior and the second one by non-elastic one which is still controlled by the steel reinforcement. Total chloride profiles in relation to the depth were measured in different locations of the tensile zone of reinforced beam B1CL. Until 15 mm depth, the chloride content is constant and corresponds to the maximum chloride content available, taking into account both concrete porosity (where free chloride content corresponds to 35 g/l of NaCl) and concrete binding capacity. Beyond 15 mm depth, total chloride profiles appear to be pure diffusion profiles allowing to calculate the effective diffusion coefficient by using a saturated model of chloride motion taking into account the non-linear binding capacity of concrete. The evolution of effective diffusion coefficient in the beam field (B1CL) is strongly correlated with the field of non-elastic strains in concrete (B1T) and can increase up to 40% in the part of the beam where the non-elastic damage is the more important.
{"title":"Chloride Diffusion in Reinforced Concrete Beam Under Sustained loading","authors":"A. Castel, O. Francy, R. François, G. Arliguie","doi":"10.14359/10607","DOIUrl":"https://doi.org/10.14359/10607","url":null,"abstract":"The purpose of this paper is to determine the effect of mechanical loading on the transport properties of concrete. The test specimen (B1CL) used for chloride measurement, was a three-meter long reinforced beam kept in a loading state, in a confined salt fog (35 g/l of NaCl) for fourteen years. Because of corrosion of reinforcement, the characterization of mechanical loading was made on another old beam (B1T) cast at the same time but stored in a non-aggressive environment. The measurement of tensile concrete strains using strain gauges showed two parts in the bottom of the beam: the first one is characterized by an elastic behavior and the second one by non-elastic one which is still controlled by the steel reinforcement. Total chloride profiles in relation to the depth were measured in different locations of the tensile zone of reinforced beam B1CL. Until 15 mm depth, the chloride content is constant and corresponds to the maximum chloride content available, taking into account both concrete porosity (where free chloride content corresponds to 35 g/l of NaCl) and concrete binding capacity. Beyond 15 mm depth, total chloride profiles appear to be pure diffusion profiles allowing to calculate the effective diffusion coefficient by using a saturated model of chloride motion taking into account the non-linear binding capacity of concrete. The evolution of effective diffusion coefficient in the beam field (B1CL) is strongly correlated with the field of non-elastic strains in concrete (B1T) and can increase up to 40% in the part of the beam where the non-elastic damage is the more important.","PeriodicalId":184301,"journal":{"name":"\"SP-200: Fifth CANMET/ACI Conference on Recent Advances in Concrete Technology-Proceeding, Fifth International Conference\"","volume":"171 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114648525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The results of laboratory and in situ tests of a number of different types of coatings commercially available in Croatia (polymer-cement, epoxy, acrylic, epoxy-acrylic and epoxy-polyurethane), used for reinforced concrete protection of the KRK bridge, are presented. The tests have been carried out throughout the last ten years. Some coatings like epoxy and polymer-cement were found completely unacceptable for technical reasons. However, epoxy-polyurethane coatings applied on the concrete finished with a thin layer of epoxy-cement mortar are estimated rather effective. They had high adhesion strength (above 2.0 MPa), very low gas permeability, low capillary absorption, satisfactory water vapor diffusion and satisfactory aging resistance.
{"title":"Old and New Coatings Against Chloride Ingress in Concrete","authors":"J. Beslać, K. Mavar","doi":"10.14359/10602","DOIUrl":"https://doi.org/10.14359/10602","url":null,"abstract":"The results of laboratory and in situ tests of a number of different types of coatings commercially available in Croatia (polymer-cement, epoxy, acrylic, epoxy-acrylic and epoxy-polyurethane), used for reinforced concrete protection of the KRK bridge, are presented. The tests have been carried out throughout the last ten years. Some coatings like epoxy and polymer-cement were found completely unacceptable for technical reasons. However, epoxy-polyurethane coatings applied on the concrete finished with a thin layer of epoxy-cement mortar are estimated rather effective. They had high adhesion strength (above 2.0 MPa), very low gas permeability, low capillary absorption, satisfactory water vapor diffusion and satisfactory aging resistance.","PeriodicalId":184301,"journal":{"name":"\"SP-200: Fifth CANMET/ACI Conference on Recent Advances in Concrete Technology-Proceeding, Fifth International Conference\"","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129846225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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