Effect of the Combined Using of Fly Ash and Granulated Blast Furnace Slag on Properties of Cementless Alkali-Activated Mortar

2011 ◽  
Vol 287-290 ◽  
pp. 916-921
Author(s):  
Kyung Taek Koh ◽  
Gum Sung Ryu ◽  
Si Hwan Kim ◽  
Jang Hwa Lee
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Curing Temperature ◽  
Mixture Ratio ◽  
Granulated Blast Furnace Slag ◽  
Alkaline Activator ◽  
Furnace Slag ◽  
Alkali Activated

This paper examines the effects of the mixture ratio of fly ash/slag, the type of alkaline activators and curing conditions on the workability, compressive strength and microstructure of cementless alkali-activated mortar. The investigation showed that the mixture ratio of fly ash/slag and the type of alkaline activator have significant influence on the workability and strength, whereas the curing temperature has relatively poor effect. An alkali-activated mortar using a binder composed of 50% of fly ash and 50% of granulated blast furnace slag and alkaline activator made of 9M NaOH and sodium silicate in proportion of 1:1 is seen to be able to develop a compressive strength of 65 MPa at age of 28 days even when cured at ambient temperature of 20°C.

scholarly journals Protective Geopolymer Coatings Containing Multi-Componential Precursors: Preparation and Basic Properties Characterization

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3448
Author(s):  
Chenhui Jiang ◽  
Aiying Wang ◽  
Xufan Bao ◽  
Zefeng Chen ◽  
Tongyuan Ni ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Portland Cement ◽  
Adhesive Strength ◽  
Blast Furnace Slag ◽  
Setting Time ◽  
Rapid Test ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

This paper presents an experimental investigation on geopolymer coatings (GPC) in terms of surface protection of civil structures. The GPC mixtures were prepared with a quadruple precursor simultaneously containing fly ash (FA), ground granulated blast-furnace slag (GBFS), metakaolin (MK), and Portland cement (OPC). Setting time, compressive along with adhesive strength and permeability, were tested and interpreted from a perspective of potential applications. The preferred GPC with favorable setting time (not shorter than 120 min) and desirable compressive strength (not lower than 35 MPa) was selected from 85 mixture formulations. The results indicate that balancing strength and setting behavior is viable with the aid of the multi-componential precursor and the mixture design based on total molar ratios of key oxides or chemical elements. Adhesive strength of the optimized GPC mixtures was ranged from 1.5 to 3.4 MPa. The induced charge passed based on a rapid test of coated concrete specimens with the preferred GPC was 30% lower than that of the uncoated ones. Setting time of GPC was positively correlated with η[Si/(Na+Al)]. An abrupt increase of setting time occurred when the molar ratio was greater than 1.1. Compressive strength of GPC was positively affected by mass contents of ground granulated blast furnace slag, metakaolin and ordinary Portland cement, and was negatively affected by mass content of fly ash, respectively. Sustained seawater immersion impaired the strength of GPC to a negligible extent. Overall, GPC potentially serves a double purpose of satisfying the usage requirements and achieving a cleaner future.

scholarly journals Alkali-activated concretes based on fly ash and blast furnace slag: Compressive strength, water absorption and chloride permeability

2020 ◽  
Vol 40 (2) ◽  
Author(s):  
Daniela Eugenia Angulo-Ramírez ◽  
William Gustavo Valencia-Saavedra ◽  
Ruby Mejía de Gutiérrez
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Water Absorption ◽  
Blast Furnace Slag ◽  
Construction Materials ◽  
Chloride Ion ◽  
Chloride Permeability ◽  
Alkaline Activator ◽  
Furnace Slag

Concretes based on alkaliactivated binders have attracted considerable attention as new alternative construction materials, which can substitute Portland Cement (OPC) in several applications. These binders are obtained through the chemical reaction between an alkaline activator and reactive aluminosilicate materials, also named precursors. Commonly used precursors are fly ash (FA), blast furnace slag (GBFS), and metakaolin. The present study evaluated properties such as compressive strength, rate of water absorption (sorptivity), and chloride permeability in two types of alkaliactivated concretes (AAC): FA/GBFS 80/20 and GBFS/OPC 80/20. OPC and GBFS/OPC* concretes without alkaliactivation were used as reference materials. The highest compressive strength was observed in the FA/GBFS concrete, which reported 26,1% greater strength compared to OPC concrete after 28 days of curing. The compressive strength of alkaliactivated FA/GBFS 80/20 and GBFS/OPC 80/20 was 61 MPa and 42 MPa at 360 days of curing, respectively. These AAC showed low permeability to the chloride ion and a reduced water absorption. It is concluded that these materials have suitable properties for various applications in the construction sector.

Experimental Study on Compound Binding Material of Alkali Activated Metakaolin and Ground Granulated Blast Furnace Slag

2011 ◽  
Vol 287-290 ◽  
pp. 1275-1279
Author(s):  
Yong Jia He ◽  
Lin Nu Lu ◽  
Shu Guang Hu
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Hydration Product ◽  
Alkali Activation ◽  
Granulated Blast Furnace Slag ◽  
Binding Material ◽  
Measurement Results ◽  
Furnace Slag ◽  
Alkali Activated

Compound binding material was prepared by the alkali activation of metakaolin and ground granulated blast furnace slag. Hydration product components, microstructure and mechanical properties of the hardened paste were investigated by IR, XRD, SEM, MIP, and compressive strength measurement. Results indicated that hydration products included C-S-H and geopolymer, and both of them were amorphous although there were differences in their structure and morphology. When the dosage of slag was less than 50%, the compressive strength of hardened paste increased as the dosage increased, which was mainly because C-S-H produced by the reaction of GGBFS and alkali filled void in geopolymer phase, and part of unreacted slag particles acting as microaggregate to prevent from extension of microcrack in the hardened paste, so the porosity of hardened paste decreased and compressive strength increased.

scholarly journals Investigation of Mechanical Properties, Durability and Microstructure of Low-Clinker High-Performance Concretes Incorporating Ground Granulated Blast Furnace Slag, Siliceous Fly Ash and Silica Fume

2021 ◽  
Vol 11 (2) ◽  
pp. 830
Author(s):  
Katarzyna Konieczna ◽  
Karol Chilmon ◽  
Wioletta Jackiewicz-Rek
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
High Performance ◽  
Cement Clinker ◽  
Water Penetration ◽  
Granulated Blast Furnace Slag ◽  
Portland Cement Clinker ◽  
Furnace Slag

The main assumption of eco-efficient High-Performance Concrete (HPC) design is the reduction of Portland cement clinker content without negatively affecting the composite’s mechanical and durability properties. In this paper, three low-clinker HPC mixtures incorporating slag cement (CEM III/B as per EN 197-1) and Supplementary Cementitious Materials (SCMs)—Ground Granulated Blast Furnace Slag (GGBFS), Siliceous Fly Ash (SFA) and Silica Fume (SF)—were designed. The maximum amount of Portland cement clinker from CEM III/B varied from 64 to 116 kg in 1 m3 of concrete mix. The compressive strength of HPC at 2, 7, 14, 28, 56, 90 days, and 2 years after casting, as well as the modulus of elasticity on 2-year-old specimens, was tested. The depth of water penetration under pressure and internal frost resistance in freeze–thaw tests were evaluated after 56 days of curing. Additionally, the concrete pH value tests were performed. The microstructure of 2-year-old HPC specimens was analyzed using Scanning Electron Microscopy (SEM). The research proved that it is possible to obtain low-clinker High-Performance Concretes that reach compressive strength of 76–92 MPa after 28 days of curing, show high values of modulus of elasticity (49–52 GPa) as well as increased resistance to frost and water penetration under pressure.

scholarly journals Evaluation of Strength Development in Concrete with Ground Granulated Blast Furnace Slag Using Apparent Activation Energy

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 442 ◽  
Author(s):  
Hyun-Min Yang ◽  
Seung-Jun Kwon ◽  
Nosang Vincent Myung ◽  
Jitendra Kumar Singh ◽  
Han-Seung Lee ◽  
...  
Keyword(s):  
Activation Energy ◽  
Compressive Strength ◽  
Blast Furnace ◽  
Apparent Activation Energy ◽  
Blast Furnace Slag ◽  
Curing Temperature ◽  
Strength Development ◽  
Replacement Ratio ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

Ground granulated blast furnace slag (GGBFS) conventionally has been incorporated with ordinary Portland cement (OPC) owing to reduce the environmental load and enhance the engineering performance. Concrete with GGBFS shows different strength development of normal concrete, but sensitive, to exterior condition. Thus, a precise strength evaluation technique based on a quantitative model like full maturity model is required. Many studies have been performed on strength development of the concrete using equivalent age which is based on the apparent activation energy. In this process, it considers the effect of time and temperature simultaneously. However, the previous models on the apparent activation energy of concrete with mineral admixtures have limitation, and they have not considered the effect of temperature on strength development. In this paper, the apparent activation energy with GGBFS replacement ratio was calculated through several experiments and used to predict the compressive strength of GGBFS concrete. Concrete and mortar specimens with 0.6 water/binder ratio, and 0 to 60% GGBFS replacement were prepared. The apparent activation energy (Ea) was experimentally derived considering three different curing temperatures. Thermodynamic reactivity of GGBFS mixed concrete at different curing temperature was applied to evaluate the compressive strength model, and the experimental results were in good agreement with the model. The results show that when GGBFS replacement ratio was increased, there was a delay in compressive strength.

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