Effects of slag substitution on physical and mechanical properties of fly ash-based alkali activated binders (AABs)

This study focuses on the development of an alkali-activated lightweight foamed material (AA-LFM) with enhanced density. Several mixes of tungsten waste mud (TWM), grounded waste glass (WG), and metakaolin (MK) were produced. Al powder as a foaming agent was added, varying from 0.009 w.% to 0.05 w.% of precursor weight. Expanded granulated cork (EGC) particles were incorporated (10% to 40% of the total volume of precursors). The physical and mechanical properties of the foamed materials obtained, the effects of the amount of the foaming agent and the percentage of cork particles added varying from 10 vol.% to 40% are presented and discussed. Highly porous structures were obtained, Pore size and cork particles distribution are critical parameters in determining the density and strength of the foams. The compressive strength results with different densities of AA-LFM obtained by modifying the foaming agent and cork particles are also presented and discussed. Mechanical properties of the cured structure are adequate for lightweight prefabricated building elements and components.

Download Full-text

Physical and Mechanical Properties of Cement Paste Were Used Partially with Fly Ash and Kaolin Waste

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.866.199 ◽

2017 ◽

Vol 866 ◽

pp. 199-203

Author(s):

Chidchanok Chainej ◽

Suparut Narksitipan ◽

Nittaya Jaitanong

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Room Temperature ◽

Physical And Mechanical Properties ◽

Partial Replacement ◽

X Ray Diffraction ◽

X Ray ◽

Lime Water ◽

Diffraction Patterns ◽

Iron Mold

The aims of this research were study the microstructures and mechanical properties for partial replacement of cement with Fly ash (FA) and kaolin waste (KW). Ordinary Portland cement were partially replaced with FA and KW in the range of 25-35% and 10-25% by weight of cement powder. The kaolin waste was ground for 180 minutes before using. The specimen was packing into an iron mold which sample size of 5×5×5 cm3. Then, the specimens were kept at room temperature for 24 hours and were moist cured in the incubation lime water bath at age of 3 days. After that the specimens were dry cured with plastic wrap at age of 3, 7, 14 and 28 days. After that the compounds were examined by x-ray diffraction patterns (XRD) and the microstructures were examined by scanning electron microscopy (SEM). The compressive strength was then investigated.

Download Full-text

Effect of CaSO4 Incorporation on Pore Structure and Drying Shrinkage of Alkali-Activated Binders

Materials ◽

10.3390/ma12101673 ◽

2019 ◽

Vol 12 (10) ◽

pp. 1673 ◽

Cited By ~ 3

Author(s):

Hyeongmin Son ◽

Sol Moi Park ◽

Joon Ho Seo ◽

Haeng Ki Lee

Keyword(s):

Fly Ash ◽

Pore Structure ◽

Drying Shrinkage ◽

Phase Changes ◽

X Ray Diffraction ◽

Activated Slag ◽

Capillary Tension ◽

Alkali Activated Binders ◽

Internal Pore Structure ◽

Alkali Activated

This present study investigates the effects of CaSO4 incorporation on the pore structure and drying shrinkage of alkali-activated slag and fly ash. The slag and fly ash were activated at a 5:5 ratio by weighing with a sodium silicate. Thereafter, 0%, 5%, 10%, and 15% of CaSO4 were incorporated to investigate the changes in phase formation and internal pore structure. X-Ray Diffraction (XRD), thermogravimetry (TG)/derivative thermogravimetry (DTG), mercury intrusion porosimetry (MIP), nuclear magnetic resonance (NMR), and drying shrinkage tests were carried out to find the correlation between the pore structure and drying shrinkage of the specimens. The results showed that CaSO4 incorporation increased the formation of thenardite, and these phase changes affected the pore structure of the activated fly ash and slag. The increase in the CaSO4 content increased the pore distribution in the mesopore. As a result, the capillary tension and drying shrinkage decreased.

Download Full-text

The physical and mechanical properties of fly ash geopolymers with various S/L ratios

10.1063/5.0023108 ◽

2020 ◽

Author(s):

N. H. Teng ◽

H. C. Yong ◽

M. M. A. Abdullah ◽

N. Yong-Sing ◽

K. Hussin

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Physical And Mechanical Properties

Download Full-text

Influence of Different Mineral Precursors on the Properties of Fly Ash Based Alkali-Activated Mortars

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.761.73 ◽

2018 ◽

Vol 761 ◽

pp. 73-78 ◽

Cited By ~ 1

Author(s):

Matej Špak ◽

Pavel Raschman

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Chemical Composition ◽

Coal Combustion ◽

Pure Aluminum ◽

Partial Replacement ◽

Black Coal ◽

Fly Ashes ◽

Final Composition ◽

Alkali Activated

Alkali-activated materials based on fly ash are widely developed and also produced on the present. Some of fly ashes are not suitable for production of alkali-activated materials because of their inconvenient chemical composition. Alumina-silicates are the most important components that are needed to accomplish the successful reaction. The proper content of amorphous phase of alumina-silicates and its proportion as well should be provided for the final composition of alkali-activated materials. The influence of pure aluminum oxide powder as well as raw milled natural perlite on mechanical properties and durability of alkali-activated mortars was investigated. These minerals were used as partial replacement of fly ash coming from black coal combustion. In addition, the mortars were prepared by using different alkali activators.

Download Full-text

Alternative Concrete – Geopolymer Concrete

10.21741/9781644901533 ◽

2021 ◽

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Construction Industry ◽

Building Material ◽

Construction Materials ◽

Raw Material ◽

Geopolymer Concrete ◽

Sustainable Solutions ◽

New Construction ◽

Alkali Activated

Concrete is the most versatile, durable and reliable material and is the most used building material. It requires large amounts of Portland cement which has environmental problems associated with its production. Hence, an alternative concrete – geopolymer concrete is needed. The general aim of this book is to make significant contributions in understanding and deciphering the mechanisms of the realization of the alkali-activated fly ash-based geopolymer concrete and, at the same time, to present the main characteristics of the materials, components, as well as the influence that they have on the performance of the mechanical properties of the concrete. The book deals with in-depth research of the potential recovery of fly ash and using it as a raw material for the development of new construction materials, offering sustainable solutions to the construction industry.

Download Full-text

Leaching, carbonation and chloride ingress in reinforced alkali-activated fly ash mortars

MATEC Web of Conferences ◽

10.1051/matecconf/201819902025 ◽

2018 ◽

Vol 199 ◽

pp. 02025 ◽

Cited By ~ 1

Author(s):

Gregor J. G. Gluth ◽

Petr Hlaváček ◽

Steffi Reinemann ◽

Gino Ebell ◽

Jürgen Mietz

Keyword(s):

Fly Ash ◽

Visual Inspection ◽

Electrochemical Behaviour ◽

Transport Coefficients ◽

Chloride Penetration ◽

Chloride Ingress ◽

Reaction Products ◽

Steel Bars ◽

Alkali Activated Binders ◽

Alkali Activated

Alkali-activated fly ash mortars were studied with regard to durability-relevant transport coefficients and the electrochemical behaviour of embedded carbon steel bars on exposure of the mortars to leaching, carbonation and chloride penetration environments. The transport coefficients differed considerably between different formulations, being lowest for a mortar with BFS addition, but still acceptable for one of the purely fly ash-based mortars. Leaching over a period of ~300 days in de-ionized water did not lead to observable corrosion of the embedded steel, as shown by the electrochemical data and visual inspection of the steel. Exposure to 100 % CO2 atmosphere caused steel depassivation within approx. two weeks; in addition, indications of a deterioration of the mortar were observed. The results are discussed in the context of the different reaction products expected in highand low-Ca alkali-activated binders, and the alterations caused by leaching and carbonation.

Download Full-text