A study on the mechanical properties of alkali activated ground granulated blast furnace slag and fly ash concrete

Author(s):  
R. Manojsuburam ◽  
E. Sakthivel ◽  
E. Jayanthimani
2016 ◽  
Vol 851 ◽  
pp. 141-146
Author(s):  
Jan Koplík ◽  
Miroslava Smolková ◽  
Jakub Tkacz

The ability of alkali-activated materials (AAMs) to fix and immobilize heavy metals was investigated. Two raw materials were used to prepare alkali-activated matrices – high-temperature fly ash and blast furnace slag (BFS). NaOH served as an alkaline activator. Two heavy metals (Mn, Ni) were added in different amounts to find out the influence of dosage of heavy metal on the mechanical properties of the matrices and the leachability. Leachability was measured as concentration of heavy metals in leachates (ČSN EN 12457-4) by inductively coupled plasma/optical emission spectrometry (ICP/OES). Structure of prepared matrices was characterized by scanning electron microscopy (SEM). Increasing of addition of heavy metals led to decrease of mechanical properties of matrices. The leaching tests showed, that both matrices can immobilize Mn and Ni in dosages of 0.1 – 2,5%. Higher dosages caused deterioration of the matrices and increased the leachability. After alkali activation both heavy metals were transformed into the form of insoluble salts.


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Jun Yang ◽  
Qiang Wang ◽  
Yuqi Zhou

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.


2021 ◽  
Vol 13 (2) ◽  
pp. 873
Author(s):  
Numanuddin M. Azad ◽  
S.M. Samindi M.K. Samarakoon

There has been a significant movement in the past decades to develop alternative sustainable building material such as geopolymer cement/concrete to control CO2 emission. Industrial waste contains pozzolanic minerals that fulfil requirements to develop the sustainable material such as alumino-silicate based geopolymer. For example, industrial waste such as red mud, fly ash, GBFS/GGBS (granulated blast furnace slag/ground granulated blast furnace slag), rice husk ash (RHA), and bagasse ash consist of minerals that contribute to the manufacturing of geopolymer cement/concrete. A literature review was carried out to study the different industrial waste/by-products and their chemical composition, which is vital for producing geopolymer cement, and to discuss the mechanical properties of geopolymer cement/concrete manufactured using different industrial waste/by-products. The durability, financial benefits and sustainability aspects of geopolymer cement/concrete have been highlighted. As per the experimental results from the literature, the cited industrial waste has been successfully utilized for the synthesis of dry or wet geopolymers. The review revealed that that the use of fly ash, GBFS/GGBS and RHA in geopolymer concrete resulted high compressive strength (i.e., 50 MPa–70 MPa). For high strength (>70 MPa) achievement, most of the slag and ash-based geopolymer cement/concrete in synergy with nano processed waste have shown good mechanical properties and environmental resistant. The alkali-activated geopolymer slag, red mud and fly ash based geopolymer binders give a better durability performance compared with other industrial waste. Based on the sustainability indicators, most of the geopolymers developed using the industrial waste have a positive impact on the environment, society and economy.


2020 ◽  
Vol 2 (3) ◽  
pp. 128-133
Author(s):  
Addepalli Mallinadh Kashyap ◽  
Tanimki Chandra Sekhar Rao ◽  
N.V.Ramana Rao

The utilisation of pozzolanic materials as the replacement to conventional cement material have the potentiality to mitigate the pollution caused by the émission of carbon based green house gases which are a main source for global warming problem. For every production of 1 ton of cement it was approximated that the emission of carbon based green house gases are about 1 ton. Keeping this in view, a new material called Geopolymer which was first coined by Davidovits has gained a lot of interest by the researchers. In this study, different molarity variations of NaOH in the order of 4M, 6M, 8M, 10M, 12M and 14M and also the blending of  mineral admixtures like Fly Ash and Ground Granulated Blast Furnace Slag with percentages (50%+50%) and the mechanical properties of normal M30 and high strength grade M70 binary blended Geopolymer concrete were studied after 28 days of ambient curing and were reported. The test results revealed that the effect of molar concentration of NaOH at 12 M is effective and the optimum replacement of mineral composition of source materials is (50%+50%) fly ash and ground granulated blast furnace slag.  


2011 ◽  
Vol 287-290 ◽  
pp. 916-921
Author(s):  
Kyung Taek Koh ◽  
Gum Sung Ryu ◽  
Si Hwan Kim ◽  
Jang Hwa Lee

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.


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