scholarly journals Reactivity Assessment of Modified Ferro Silicate Slag by R3 Method

2021 ◽  
Vol 11 (1) ◽  
pp. 366
Author(s):  
Pithchai Pandian Sivakumar ◽  
Stijn Matthys ◽  
Nele De Belie ◽  
Elke Gruyaert
Keyword(s):  
Heat Release ◽  
Water Content ◽  
Bound Water ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Reaction Products ◽  
Silicate Slag ◽  
Hydration Mechanism ◽  
Novel Method ◽  
Bound Water Content

Traditional methods to track the reactivity of supplementary cementitious materials (SCMs) and their contribution to the hydration mechanism mostly use Portland Cement (PC) as an activator. Alternatively, a novel method to assess the reactivity of SCMs called R3 was recently presented. This novel method uses lab grade chemicals such as portlandite (CH), K2SO4, KOH, and CaCO3 to activate the SCM by resembling the pH of the alkaline pore solution created by PC. By using this method, the reactivity of the SCM can be easily quantified from measured heat release, bound water content, and CH consumption. The primary objective of the current study is to apply the novel methodology to analyze the reactivity of Modified Ferro Silicate (MFS) Cu slag benchmarked against siliceous fly ash (FA), ground granulated blast-furnace slag (GGBFS), and inert quartz filler. GGBFS showed the highest cumulative heat release and bound water content due to its latent hydraulic behavior. Determination with XRD analysis of the major phase of the R3 model MFS slag paste showed the participation of Fe in the hydration mechanism by forming Fe-AFm. R3 paste with GGBFS showed the presence of hydrotalcite/Al-AFm, whereas FA showed the presence of ettringite (AFt) as their crystalline reaction products. The experiments also indicate that the MFS slag acts as a reactive pozzolanic material with an acceptable performance in heat release, bound water content, and CH consumption, and can be used as SCM to make concrete. With the possibility of using MFS slag as SCM to replace part of PC, sustainability and circular economy can be fairly well achieved.

scholarly journals Recent developments in reactivity testing of supplementary cementitious materials

2021 ◽  
Vol 6 ◽  
pp. 131-139
Author(s):  
Prannoy Suraneni
Keyword(s):  
Heat Release ◽  
Calcium Hydroxide ◽  
Bound Water ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Concrete Durability ◽  
Index Test ◽  
Bulk Resistivity ◽  
Amorphous Content ◽  
Two Parameters

Identification and rapid characterization of novel supplementary cementitious materials (SCMs) is a critical need, driven by shortfalls in conventional SCMs. In this study, we present a discussion of recently developed reactivity tests – the R3 test, the modified R3 test, the lime strength test, and the bulk resistivity index test. These tests measure reactivity parameters such as heat release, bound water, calcium hydroxide consumption, strength, and bulk resistivity. All tests can screen inert from reactive materials. To additionally differentiate pozzolanic and latent hydraulic materials, two parameters, for example, calcium hydroxide consumption and heat release, are needed. The influences of SCM bulk chemistry, amorphous content, and fineness on measured reactivity are outlined. Reactivity test outputs can predict strength and durability of cement paste/mortar/concrete; however, caution must be exercised as these properties are influenced by a variety of other factors independent of reactivity. Thoughts are provided on using reactivity tests to screen materials for concrete durability.

Effect of Modified Metakaolin on Water Content of Hardened Cementitious Materials of Concrete

2014 ◽  
Vol 599 ◽  
pp. 29-33
Author(s):  
Kang Wang ◽  
Yu Ping Zhang ◽  
Ting Wei Cao ◽  
Jie Zhang ◽  
Zhong He Shui
Keyword(s):  
Water Content ◽  
Early Stage ◽  
Autogenous Shrinkage ◽  
Bound Water ◽  
Cementitious Materials ◽  
Hydration Reaction ◽  
Hydration Products ◽  
Evaporable Water ◽  
Bound Water Content ◽  
Structure Water

The effect of modified metakaolin (MMK) on the evaporable water and chemically bound water content of hardened cementitious materials have been investigated. Concrete specimens with 0%, 4%, 7% and 10% of MMK were included. Metakaolin was pre-modified in order to increase the dispersion and contact angle, which might further improve the workability of the concrete. The experimental results showed that both the evaporable water and bound water were increased with the increasing of the MMK content. MMK has a special layered structure. Water can get into the layers through this special layer during the mixing of concrete specimens. Part of MMK with water between the layers didn’t participate in the hydration reaction at the early stage of the hydration, which increased the evaporable water of the cementious materials. The water absorbed in MMK will be released to promote the formation of hydration products and thus the chemically bound water content will increase continuously at the later stages. It also reduced the autogenous shrinkage of the specimens which caused by the decrease of water in capillary pores at low water cement ratio (0.3).

Capillary suction time (CST) as a measure of sludge dewaterability

1996 ◽  
Vol 34 (3-4) ◽  
pp. 443-448 ◽  
Author(s):  
G. W. Chen ◽  
W. W. Lin ◽  
D. J. Lee
Keyword(s):  
Water Content ◽  
Specific Resistance ◽  
Bound Water ◽  
The Other ◽  
Solid Concentration ◽  
Capillary Suction ◽  
Good Index ◽  
Other Hand ◽  
Sludge Dewaterability ◽  
Bound Water Content

The feasibility of employment of capillary suction time (CST) for characterizing the dewaterability of excess activated sludges was examined. The CST was shown as a good index for sludge filterability, if only the product of solid concentration and average specific resistance is of interest. On the other hand, the bound water content cannot be directly evaluated from the CST data.

scholarly journals Bound Water Content of Vegetative and Spore Forms of Bacteria

1938 ◽  
Vol 36 (1) ◽  
pp. 99-105 ◽  
Author(s):  
C. A. Friedman ◽  
B. S. Henry
Keyword(s):  
Water Content ◽  
Bound Water ◽  
Bound Water Content

scholarly journals Studies on the Maximum Bound Water Content by the Differential Scanning Calorimetry on Lipstick

2012 ◽  
Vol 38 (3) ◽  
pp. 197-200
Author(s):  
Khee-Hwan Choi ◽  
Myung-Jin Ann ◽  
Hong-Ha Son ◽  
Kyong-Seub Kim ◽  
Sang-Min Lee ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Water Content ◽  
Bound Water ◽  
Scanning Calorimetry ◽  
Bound Water Content
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