A Review of Alkali-Activated Slag as Cement Replacement

2019 ◽  
Vol 803 ◽  
pp. 262-266
Author(s):  
Osama Ahmed Mohamed ◽  
Maadoum M. Mustafa
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Construction Industry ◽  
Ordinary Portland Cement ◽  
Environmental Footprint ◽  
Alkali Activated Slag ◽  
Cement Replacement ◽  
Activated Slag ◽  
Alkali Activated

Alkali activated slag (AAS) offers opportunities to the construction industry as an alternative to ordinary Portland cement (OPC). The production of OPC and its use contributes significantly to release of CO2 into the atmosphere while AAS is an industrial by-product that contributes much less to the environmental footprint that needs to be recycled if not landfilled. This paper outlines some of the key properties, merits and demerits of AAS when used as alternative to OPC. Competitive compressive strength of AAS concrete is amongst of the advantages of replacing cement with AAS while high shrinkage and carbonation levels are potential disadvantages.

scholarly journals Effect of Elevated Temperature on Alkali Activated Slag and Fly Ash based Geopolymer Concrete

2020 ◽  
Vol 9 (4) ◽  
pp. 1241-1250
Keyword(s):  
Compressive Strength ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Flexural Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Geopolymer Concrete ◽  
Base Materials ◽  
Activated Slag ◽  
Alkali Activated

Activated Slag (AAS) and Fly Ash (FA) based geopolymer concrete a new blended alkali-activated concrete that has been progressively studied over the past years because of its environmental benefits superior engineering properties. Geopolymer has many favorable characteristics in comparison to Ordinary Portland Cement. Many base materials could be utilized to make geopolymer with the convenient concentration of activator solution. In this study, the experimental program composed of two phases; phase on divided into four groups; Group one deliberated the effect of sodium hydroxide molarity and different curing condition on compressive strength. Group two studied the effect of alkali activated solution (NaOH and Na2SiO3) content on compressive strength and workability. The effect of sand replacement with slag on compressive strength and workability was explained in group three. Group four studied the effect of slag replacement with several base materials Fly Ash (FA), Ordinary Portland Cement (OPC), pulverized Red Brick (PRB), and Meta Kaolin (MK). Phase two contains three mixtures from phase one which had the highest compressive strength. For each mixture, the fresh concrete test was air content. In addition the hardened concrete tests were the compressive strength at 3, 7, 28, 90, 180, and 365 days, the flexural strength at 28, 90, and 365 days, and the young's modulus at 28, 90, and 365 days. Moreover; the three mixtures were exposed to elevated temperature at 100oC, 300oC, and 600oC to study the effect of elevated temperature on compressive and flexural strength.

scholarly journals Effect of Mixture Variables on Durability for Alkali-Activated Slag Cementitious

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2252 ◽  
Author(s):  
Chi-Che Hung ◽  
Yuan-Chieh Wu ◽  
Wei-Ting Lin ◽  
Jiang-Jhy Chang ◽  
Wei-Chung Yeih
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Chloride Permeability ◽  
Alkali Activated Slag ◽  
Binder Ratio ◽  
Activated Slag ◽  
Alkali Activated ◽  
Ordinary Portland Cement Concrete

In this study, the influence of three mixture variables named Sand/Aggregate ratio, Liquid/Binder ratio, and Paste/Aggregate ratio on the cementitious properties were studied. The durability of cementitious including absorption, absorption rate, resistivity, rapid chloride permeability index, and carbonation rate were examined. Results showed that the alkali-activated slag cementitious has superior durability. The trends of influences on the composites properties for these three mixture variables are similar to those for the ordinary Portland cement concrete. It means that the experiences for making the ordinary Portland cement concrete should be able to be used for the alkali-activated slag cementitious. This paper also provides a lot of data for the alkali-activated slag cementitious for future development of the mix design.

scholarly journals Strength and Drying Shrinkage of Alkali-Activated Slag Paste and Mortar

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Mao-chieh Chi ◽  
Jiang-jhy Chang ◽  
Ran Huang
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Portland Cement ◽  
Liquid Slag ◽  
Drying Shrinkage ◽  
Curing Temperature ◽  
Alkali Activated Slag ◽  
Cement Mortars ◽  
Activated Slag ◽  
Alkali Activated

The aim of this study is to investigate the strengths and drying shrinkage of alkali-activated slag paste and mortar. Compressive strength, tensile strength, and drying shrinkage of alkali-activated slag paste and mortar were measured with various liquid/slag ratios, sand/slag ratios, curing ages, and curing temperatures. Experimental results show that the higher compressive strength and tensile strength have been observed in the higher curing temperature. At the age of 56 days, AAS mortars show higher compressive strength than Portland cement mortars and AAS mortars with liquid/slag ratio of 0.54 have the highest tensile strength in all AAS mortars. In addition, AAS pastes of the drying shrinkage are higher than AAS mortars. Meanwhile, higher drying shrinkage was observed in AAS mortars than that observed comparable Portland cement mortars.

Hydration of alkali-activated slag: comparison with ordinary Portland cement

2006 ◽  
Vol 18 (3) ◽  
pp. 119-128 ◽  
Author(s):  
A. Gruskovnjak ◽  
B. Lothenbach ◽  
L. Holzer ◽  
R. Figi ◽  
F. Winnefeld
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Alkali Activated Slag ◽  
Activated Slag ◽  
Alkali Activated

scholarly journals Effects of Light-Burnt Dolomite Incorporation on the Setting, Strength, and Drying Shrinkage of One-Part Alkali-Activated Slag Cement

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2874 ◽  
Author(s):  
In Kyu Jeon ◽  
Jae Suk Ryou ◽  
Sadam Hussain Jakhrani ◽  
Hong Gi Kim
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Setting Time ◽  
Drying Shrinkage ◽  
Slag System ◽  
Strength Development ◽  
Alkali Activated Slag ◽  
Granulated Blast Furnace Slag ◽  
Activated Slag ◽  
Alkali Activated

This study investigates the potential of light-burnt dolomite (LBD) as a supplementary cementitious material with ground granulated blast furnace slag (GGBFS) and Ordinary Portland cement (OPC). In this work, LBD was substituted for up to 20% of GGBFS in sodium sulfate-activated slag systems. The effects of LBD incorporation on the flow, setting time, compressive and flexural strength development, and drying shrinkage were explored with, X-ray diffraction and thermogravimetric analyses. LBD incorporation resulted in greater strength development of an alkali-activated slag system. The optimum LBD content for strength development was 10%, regardless of ordinary Portland cement content. In addition, LBD decreased the drying shrinkage, accelerated the hydration process, and induced hydrotalcite formation, which can be attributed to the reactive MgO inside LBD.

scholarly journals The Effect of Different Types of Internal Curing Liquid on the Properties of Alkali-Activated Slag (AAS) Mortar

2021 ◽  
Vol 13 (4) ◽  
pp. 2407
Author(s):  
Guang-Zhu Zhang ◽  
Xiao-Yong Wang ◽  
Tae-Wan Kim ◽  
Jong-Yeon Lim ◽  
Yi Han
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Deionized Water ◽  
Internal Curing ◽  
Control Group ◽  
Alkali Activated Slag ◽  
Different Types ◽  
Naoh Solution ◽  
Activated Slag ◽  
Alkali Activated

This study shows the effect of different types of internal curing liquid on the properties of alkali-activated slag (AAS) mortar. NaOH solution and deionized water were used as the liquid internal curing agents and zeolite sand was the internal curing agent that replaced the standard sand at 15% and 30%, respectively. Experiments on the mechanical properties, hydration kinetics, autogenous shrinkage (AS), internal temperature, internal relative humidity, surface electrical resistivity, ultrasonic pulse velocity (UPV), and setting time were performed. The conclusions are as follows: (1) the setting times of AAS mortars with internal curing by water were longer than those of internal curing by NaOH solution. (2) NaOH solution more effectively reduces the AS of AAS mortars than water when used as an internal curing liquid. (3) The cumulative heat of the AAS mortar when using water for internal curing is substantially reduced compared to the control group. (4) For the AAS mortars with NaOH solution as an internal curing liquid, compared with the control specimen, the compressive strength results are increased. However, a decrease in compressive strength values occurs when water is used as an internal curing liquid in the AAS mortar. (5) The UPV decreases as the content of zeolite sand that replaces the standard sand increases. (6) When internal curing is carried out with water as the internal curing liquid, the surface resistivity values of the AAS mortar are higher than when the alkali solution is used as the internal curing liquid. To sum up, both NaOH and deionized water are effective as internal curing liquids, but the NaOH solution shows a better performance in terms of reducing shrinkage and improving mechanical properties than deionized water.

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