scholarly journals Mechanical and Durability Properties of Cementless Concretes Made Using Three Types of CaO-Activated GGBFS Binders

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 271
Author(s):  
Woo Sung Yum ◽  
Juan Yu ◽  
Dongho Jeon ◽  
Haemin Song ◽  
Sungwon Sim ◽  
...  
Keyword(s):  
Chemical Resistance ◽  
H2so4 Solution ◽  
Durability Test ◽  
Sulfate Ions ◽  
Air Content ◽  
Durability Properties ◽  
Granulated Blast Furnace Slag ◽  
Concrete Mixtures ◽  
Furnace Slag ◽  
Hcl Solution

This study examined the mechanical and durability properties of CaO-activated ground-granulated blast-furnace slag (GGBFS) concretes made with three different additives (CaCl2, Ca(HCOO)2, and Ca(NO3)2) and compared their properties to the concrete made with 100% Ordinary Portland Cement (OPC). All concrete mixtures satisfied targeted air content and slump ranges but exhibited significantly different mechanical and durability properties. The CaO-activated GGBFS concretes showed different strength levels, depending on the type of additive. The added CaCl2 was the most effective, but Ca(NO3)2 was the least effective at increasing mechanical strength in the CaO-activated GGBFS system. The OPC concrete showed the most excellent freezing–thawing resistance in the durability test, but only the CaO-activated GGBFS concrete with CaCl2 exhibited relatively similar resistance. In addition, the chemical resistance was significantly dependent on the type of acid solution and the type of binder. The OPC concrete had the best resistance in the HCl solution, while all CaO-activated GGBFS concretes had relatively low resistances. However, in the H2SO4 solution, all CaO-activated GGBFS concretes had better resistance than the OPC concrete. All concrete with sulfate ions had ettringite before immersion. However, when they were immersed in HCl solution, ettringite tended to decrease, and gypsum was generated. Meanwhile, the CaO-activated GGBFS concrete with CaCl2 did not change the type of reaction product, possibly due to the absence of ettringite and Ca(OH)2. When immersed in an H2SO4 solution, ettringite decreased, and gypsum increased in all concrete. In addition, the CaO-activated concrete with CaCl2 had a considerable amount of gypsum; it seemed that the dissolved C-S-H and calcite, due to the low pH, likely produced Ca2+ ions, and gypsum formed from the reaction between Ca2+ and H2SO4.

Performance of Blended Cement Concrete against Seawater Attack

2010 ◽  
Vol 64 ◽  
pp. 19-24
Author(s):  
H.H. Seleem ◽  
A.M. Rashad ◽  
B.A. El-Sabbagh
Keyword(s):  
Blended Cement ◽  
Strength Loss ◽  
Synthetic Seawater ◽  
Strength Deterioration ◽  
Ordinary Concrete ◽  
Granulated Blast Furnace Slag ◽  
Concrete Mixtures ◽  
Concrete Permeability ◽  
Pozzolanic Materials ◽  
Furnace Slag

The current work reports the influence of synthetic seawater on some of the durability aspects of an ordinary concrete mixture (control) and six pozzolan-concrete mixtures. Three types of pozzolanic materials were employed; silica fume (SF), ground granulated blast furnace slag (GGBS) and metakaolin (MK). The pozzolanic materials were employed as an addition to cement in binary and ternary combinations. All mixtures were tested for strength deterioration ratio (SDR) after 3, 6, and 12 months of exposure to synthetic seawater, permeability was measured after 6 and 12 months of exposure. It was found through this investigation that pozzolans increase the ability of concrete to withstand aggressive environment and prevent most of the deterioration signs. The pozzolanic materials serve also to increase the strength and to minimize the strength loss (SDR) upon exposure to seawater. The pozzolanic materials led to reduce concrete permeability compared to control.

scholarly journals Effect of the Addition of GGBS on the Frost Scaling and Chloride Migration Resistance of Concrete

2020 ◽  
Vol 10 (11) ◽  
pp. 3940
Author(s):  
Vera Correia ◽  
João Gomes Ferreira ◽  
Luping Tang ◽  
Anders Lindvall
Keyword(s):  
Blast Furnace Slag ◽  
Curing Temperature ◽  
Special Focus ◽  
Chloride Ingress ◽  
Air Content ◽  
Granulated Blast Furnace Slag ◽  
Chloride Migration ◽  
Migration Resistance ◽  
Efficiency Factors ◽  
Furnace Slag

Ground Granulated Blast-furnace Slag (GGBS) can partially replace cement in concrete to improve certain properties. However, some concerns regarding its performance have been raised. This research aimed at investigating the properties of concrete with GGBS, with special focus on its frost scaling and chloride ingress resistance. Concretes with different amounts of GGBS, different efficiency factors, and different air contents have been tested. The effects of other factors, namely the curing temperature, the use of superplasticizer and carbonation, have also been investigated. The results showed that the frost resistance generally decreases with the increase of the amount of GGBS. However, this research showed that it is possible to produce frost resistant concrete with up to 50% of GGBS by changing some properties of the mix (such as increasing the air content). The results also showed a significant improvement of the chloride ingress resistance for concrete with high additions of GGBS.

Effect of Aggregate Max Size on the Rheological Properties of Self Consolidating Concrete

2020 ◽  
Vol 853 ◽  
pp. 193-197
Author(s):  
Samer Al Martini ◽  
Ziad Hassan ◽  
Ahmad Khartabil
Keyword(s):  
Blast Furnace Slag ◽  
Aggregate Size ◽  
Maximum Size ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Self Consolidating Concrete ◽  
Granulated Blast Furnace Slag ◽  
Concrete Mixtures ◽  
Time Period ◽  
Furnace Slag

The effects of aggregate size and supplementary cementitious materials (SCMs) on the rheology of self-consolidating concrete (SCC) were studied in this paper. Two main concrete mixtures with different maximum aggregate sizes were prepared and investigated. The first mix had a maximum size aggregate of 5 mm and the second mix was with 20 mm max size aggregates. All mixes incorporated different dosages of Ground granulated blast furnace slag (GGBS). The rheology of all mixes investigated was measured over 2 hour time period. It was found that the size of aggregates and GGBS dosage have influence on the yield stress of studied concrete mixes.

scholarly journals Fresh, Strength and Durability Characteristics of Binary and Ternary Blended Self Compacting Concrete

2019 ◽  
Vol 9 (2) ◽  
pp. 3987-3991
Keyword(s):  
Heat Of Hydration ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Strength Gain ◽  
Self Compacting Concrete ◽  
Supplementary Cementitious Material ◽  
Durability Properties ◽  
Granulated Blast Furnace Slag ◽  
Strength And Durability ◽  
Furnace Slag

Paper Mineral admixtures being the economical alternatives to Ordinary Portland Cement (OPC) for various normal and special concretes induce desirable properties to concrete such as higher flow, low heat of hydration, higher strength gain and enhanced durability. Ground granulated blast furnace slag(GGBFS) being one of the largely used mineral admixture alongside Fly Ash as supplementary cementitious material in concrete contributes to enhanced durability properties and low heat of hydration. Various replacement percentages of GGBS at 30%, 40%, 50% and 60% are used in binary blended Self compacting concrete(SCC) in the present study. At 40% replacement level, SCC exhibited improved workability, strength and durability properties. Alccofine(Ultrafine GGBS) used in ternary blended SCC enhanced early strength gain without affecting workability of SCC to a significant extent.

scholarly journals Experimental Studies on Rheological and Durability Properties of Self Compacting Concrete by Using Quatenary Blending

10.29007/81v5 ◽  
2018 ◽  
Author(s):  
Ashika Shah ◽  
Indrajit Patel ◽  
Jagruti Shah ◽  
Gaurav Gohil
Keyword(s):  
Compressive Strength ◽  
Experimental Studies ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Self Compacting Concrete ◽  
Durability Properties ◽  
Granulated Blast Furnace Slag ◽  
Strength And Durability ◽  
Primary Contribution ◽  
Furnace Slag

In the production of Self Compacting concrete (SCC), the use of quaternary blend of supplementary cementitious materials (SCM’s) has not found enough applications. For this purpose, an effort has been done to present a mix design for M60 grade and M80 grade SCC with quaternary blending of fly ash(FA), ground granulated blast furnace slag (GGBS), silica fume (SF) in accordance with EFNARC guidelines. Findings: In this study, cement has been replaced with SCM’s from 30% to 50%. Fresh properties of concrete were tested for slump flow, T50 test and U box. The hardened properties of concrete were tested for compressive strength and durability. The tests were performed for 7, 28, 56 and 91 days. The results indicate that the use of quaternary blend has improved the workability, compressive strength and durability properties of specimens than the control specimen. Application: The primary contribution is to fill the congestedreinforcement and increase the durability and life span of the structure.

scholarly journals Gypsum-Dependent Effect of NaCl on Strength Enhancement of CaO-Activated Slag Binders

2018 ◽  
Vol 8 (12) ◽  
pp. 2515 ◽  
Author(s):  
Sungwon Sim ◽  
Hwan Lee ◽  
Dongho Jeon ◽  
Haemin Song ◽  
Woo Yum ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Binder System ◽  
Sulfate Ions ◽  
Dependent Effect ◽  
Strength Enhancement ◽  
Granulated Blast Furnace Slag ◽  
Significant Strength ◽  
Activated Slag ◽  
Furnace Slag

This study explores the combined effect of NaCl and gypsum on the strength of the CaO-activated ground-granulated blast furnace slag (GGBFS) binder system. In the CaO-activated GGBFS system, the incorporation of NaCl without gypsum did not improve the strength of the system. However, with the presence of gypsum, the use of NaCl yielded significantly greater strength than the use of either gypsum or NaCl alone. The presence of NaCl largely increases the solubility of gypsum in a solution, leading to a higher concentration of sulfate ions, which is essential for generating more and faster formations of ettringite in a fresh mixture of paste. The significant strength enhancement of gypsum was likely due to the accelerated and increased formation of ettringite, accompanied by more efficient filling of pores in the system.

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