Mutual activation of blast furnace slag and a high-calcium fly ash rich in free lime and sulfates

Date

2016-11-15

Author

Sahin, Murat
Mahyar, Mahdi
Erdoğan, Sinan Turhan

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

149
views

0
downloads

Alkaline activation of fly ash and blast furnace slag has gained interest due to a desire to avoid Portland cement in mixtures. Outstanding mechanical performance and durability is reported, but often when the activator dosage is high which can have various negative environmental impacts that can overshadow the carbon reduction benefit. This study investigates the use of a ground slag, and a high-lime fly ash, rich in free lime and sulfates, to activate each other and render mortars which don't incorporate any Portland cement or an added chemical activator, but still have useful strengths. The ash, which does not conform to standards for use in concrete, hence is nearly completely landfilled, is used as-received or after grinding. 28-day compressive strengths surpassing 13 MPa and 20 MPa were recorded, for samples cured at 23 degrees C or at 80 degrees C. Various combinations of the two powders have heats of hydration lower than that of a typical Portland cement. Ettringite and CSH are determined to be responsible for the early and ultimate strength gain. The effect of adding gypsum to the system as a low-impact activator is also investigated.

Subject Keywords

Activation, Slag, Fly ash, High-calcium, Free lime, Gypsum

URI

https://hdl.handle.net/11511/36763

Journal

CONSTRUCTION AND BUILDING MATERIALS

DOI

https://doi.org/10.1016/j.conbuildmat.2016.09.064

Collections

Department of Civil Engineering, Article

Suggestions

OpenMETU
Core

Utilization of wet-handled and dry-handled coal bottom ashes in portland cement based composites Tirkeş, Sera; Akgül, Çağla; Department of Civil Engineering (2021-9-7) Coal bottom ash (BA) is a coarse, granular, incombustible by-product collected from the bottom of coal-burning furnaces. Traditionally, it has been handled by wet-handling systems (WHS) that use large amounts of water for cooling and conveying BA. WHS relies on established technologies such as impounded hoppers or submerged scraper conveyors. However, the need for water treatment, environmental concerns such as contaminated water, and high operational costs caused a necessary shift from WHS to more sustaina...
Pozzolanic activity of clinoptilolite: A comparative study with silica fume, fly ash and a non-zeolitic natural pozzolan Uzal, B.; TURANLI, LUTFULLAH; Yücel, Hayrettin; Göncüoğlu, Mehmet Cemal; Culfaz, A. (2010-03-01) Pozzolanic activity of clinoptilolite, the most common natural zeolite mineral, was studied in comparison to silica fume, fly ash and a non-zeolitic natural pozzolan. Chemical, mineralogical and physical characterizations of the materials were considered in comparative evaluations. Pozzolanic activity of the natural zeolite was evaluated with various test methods including electrical conductivity of lime-pozzolan suspensions; and free lime content, compressive strength and pore size distribution of hardened...
Sulfate resistance of cementitious systems with mineral additives Dilek, Faruk Tuncer; Tokyay, Mustafa; Department of Civil Engineering (2002) Sulfate resistance of mortars containing limestone, trass, granulated blast furnace slag and fly ash has been evaluated using ASTM C 1012 test procedure. Prismatic and cubic mortar specimens have been stored in concentrated sodium sulfate and a mixture of sodium sulfate + magnesium sulfate solutions. Relative deterioration of the specimens has been determined by length change, weight change, strength and visual examination. From similar mixtures, cement paste specimens were prepared and structure/morphology...
Comparison of intergrinding and separate grinding for the production of natural pozzolan and GBFS-incorporated blended cements Erdogdu, K; Tokyay, Mustafa; Turker, P (1999-05-01) A portland cement clinker, a natural pozzolan, and a granulated blast furnace slag (GBFS) were used to obtain blended cements that contain 25% mineral additives. The natural pozzolan, which was softer, was more grindable and granulated blast furnace slag, which was harder, was less grindable than the clinker. Two of the cements produced were obtained by intergrinding and the other two were obtained by separate grinding and then blending. All of the blended cements and the control cement without any additive...
Graphene oxide/magnesium oxide nanocomposite: A novel catalyst for ozonation of phenol from wastewater Heidarizad, Mahdi; Şengör, Sema Sevinç (2017-01-01) Catalytic ozonation is a promising advanced oxidation technique for the removal of contaminants from water and wastewater. Graphene oxide (GO) is an oxidized derivative of graphene which contains epoxide, hydroxyl, and carboxyl groups with high surface area, and is being recently used for effective adsorption of pollutants in aquatic environments. In our previous work, we modified GO with magnesium oxide (MgO) and demonstrated the high-rate adsorption of methylene blue (MB) by the synthesized nanocomposite ...

Citation Formats

M. Sahin, M. Mahyar, and S. T. Erdoğan, “Mutual activation of blast furnace slag and a high-calcium fly ash rich in free lime and sulfates,” CONSTRUCTION AND BUILDING MATERIALS, pp. 466–475, 2016, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/36763.