Resistance Performance of Concrete Using both Blast Furnace Slag Cement and Fly Ash against Chloride Attack and Carbonation

2015 ◽  
Vol 1110 ◽  
pp. 271-276
Author(s):  
Kenta Miura ◽  
Takao Ueda ◽  
Masayuki Tsukagoshi
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Pore Structure ◽  
Blast Furnace Slag ◽  
Chloride Ions ◽  
Slag Cement ◽  
Fly Ash Concrete ◽  
Chloride Attack ◽  
Resistance Performance ◽  
Furnace Slag

From the viewpoint of effective utilization of industrial wastes and reduction of CO2 emission, the use of concrete mixed with blast furnace slag and fly ash has been promoted. However, the durability of fly ash concrete using blast furnace slag cement has not been clarified enough. About chloride attack, the resistance against the penetration of chloride ions could be improved due to the dense pore structure formed by the synegetic effect of mixing both ground granulated blast-furnace slag and fly ash into concrete. In this study, resistance performance of concrete using both blast furnace slag cement and fly ash against chloride attack and carbonation was experimentally investigated. The relationship between such resistance performance and pore structure of the concrete was also examined. As a result, the combination of blast furnace slag cement and fly ash type II resulted in the decrease of pore volume over 50 nm in the diameter and reduction of the apparent diffusion coefficient of chloride ion, but the resistance performance against carbonation of the concrete was lower than the case of the normal fly ash concrete.

Chloride Ions Penetration Resistance of New-Old Concrete

2011 ◽  
Vol 366 ◽  
pp. 518-521
Author(s):  
Zhi Min He ◽  
Jun Zhe Liu
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Beneficial Effect ◽  
Blast Furnace Slag ◽  
Penetration Resistance ◽  
Chloride Ions ◽  
Mineral Admixtures ◽  
Compound System ◽  
Astm C1202 ◽  
Furnace Slag

By use of ASTM C1202, this paper studied the influence of mineral admixtures on the chloride ions penetration resistance of the new-old concrete compound system. The results indicate that the performance of new-old concrete exert significant influence on the new-old concrete compound system. The addition of mineral admixtures improve the permeability properties of new-old concrete. Adding fly ash(FA) require a relatively longer time to get its beneficial effect. When 30% weight of cement is replaced by 10% FA and 20% ground blast furnace slag(GGBFS), the inclusion of 30% mineral admixtures significantly improve the chloride ions penetration resistance properties of the new-old concrete compound system at 28 days and 180 days.

Application of Desalination to Concrete Admixing Fly Ash or Blast-Farnace Slag

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1452-1457 ◽  
Author(s):  
Kenji Nagao ◽  
Takao Ueda ◽  
Masanobu Ashida ◽  
Toyoaki Miyagawa
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Exposed Surface ◽  
Carbonation Depth ◽  
Total Chloride ◽  
Cover Concrete ◽  
Chloride Attack ◽  
Chloride Removal ◽  
Furnace Slag

This paper mainly describes corrosion behavior of the steel bars in concrete specimens using fly ash or blast-furnace slag, deteriorated by chloride attack, carbonation of concrete, or complex of both mechanisms. Furthermore, chloride removal effect due to applying desalination to such deteriorated specimens is investigated. Results obtained from this study can be summarized as follows: (1) Carbonation depth of concrete using fly ash or blast-furnace slag was larger than that of normal concrete and the larger replacement rate of them became, the more carbonation depth of concrete increased. (2) As the result of measurement of Cl- content in concrete before desalination, in the case of carbonated specimens, soluble chloride percentage to total chloride near the exposed surface was increased with the influence of carbonation of concrete. (3) Chloride removal percentage due to applying desalination to non-carbonated specimens was 15-30% as a whole cover concrete. On the other hand, in the case of carbonated specimens, Cl- ion near the exposed surface was decreased by desalination and chloride removal percentage reached 50-80%.

Effect of Mineral Admixtures and Water/Binder Ratios on the Resistance to the Chloride Ions Penetration into Concrete

2011 ◽  
Vol 99-100 ◽  
pp. 758-761
Author(s):  
Yan Jun Hu ◽  
Yan Liang Du
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Silica Fume ◽  
Blast Furnace Slag ◽  
Chloride Ion ◽  
Test Methods ◽  
Chloride Ions ◽  
Mineral Admixtures ◽  
Chloride Permeability ◽  
Furnace Slag

In this study, concrete prisms were made with three mineral admixtures: fly ash, blast furnace slag or silica fume and with three water-to-binder ratios(w/b). Chloride penetration was measured by the rapid chloride permeability test (RCPT)-ASTM C1202, 150-days ponding test and alternate wetting and drying test by cyclic loading with salt solution and oven drying, and the results by the three test methods were compared. This paper discussed the effects of mineral admixtures and w/b on the concrete chloride permeability. Blending concrete with blast furnace slag, fly ash or silica fume was beneficial with regard to the resistance against chloride ion penetration. Concrete specimens with lower w/b showed lower chloride permeability.

scholarly journals Influence of Curing Time on the Drying Shrinkage of Concretes with Different Binders and Water-to-Binder Ratios

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Jun Yang ◽  
Qiang Wang ◽  
Yuqi Zhou
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Drying Shrinkage ◽  
Mineral Admixture ◽  
Curing Time ◽  
Cement Concrete ◽  
Fly Ash Concrete ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

Plain cement concrete, ground granulated blast furnace slag (GGBS) concrete, and fly ash concrete were designed. Three wet curing periods were employed, which were 2, 5, and 8 days. The drying shrinkage values of the concretes were measured within 1 year after wet curing. The results show that the increasing rate of the drying shrinkage of concrete containing a mineral admixture at late age is higher than that of plain cement concrete regardless of the wet curing time. With the reduction of wet curing time, the increment of total drying shrinkage of concrete decreases with the decrease of the W/B ratio. The negative effects on the drying shrinkage of fly ash concrete due to the reduction of the wet curing time are much more obvious than those of GGBS concrete and plain cement concrete. Superfine ground granulated blast furnace slag (SGGBS) can reduce the drying shrinkage of GGBS concrete and fly ash concrete when the wet curing time is insufficient.

scholarly journals The content of chlorides in blast-furnace slag cement as a factor affecting the diffusion of chloride ions in concrete

2018 ◽  
Vol 163 ◽  
pp. 05007
Author(s):  
Justyna Kuziak ◽  
Piotr Woyciechowski ◽  
Rafał Kobyłka ◽  
Aldona Wcisło
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Alternative Fuels ◽  
Diffusion Rate ◽  
Chloride Ions ◽  
Slag Cement ◽  
Wide Range ◽  
Research Problems ◽  
New Research ◽  
Furnace Slag

Blast-furnace slag cement (CEM III) has a wide range of acceptable Cl- content according to EN 197-1: 2012. This makes possible to use alternative fuels for the production of cement, which can increase the chlorides content in the clinker. However, it raises several new research problems, among them the problem of increase of the risk of Cl- penetration intensity due to the higher concentration of chlorides in cement, presented in this paper. Studies have shown that after a short hardening time (28 days) the rate of diffusion of chloride ions increases slightly with the increase in the content of chlorides in the cement CEM III, but after full stabilization of concrete properties (1 year), the content of chlorides in cement CEM III practically does not affect the diffusion rate of chloride ions in concrete.

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