Alternative Concrete – Geopolymer Concrete

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.

Mechanical Properties of Mortars Prepared by Alkali Activated Fly Ash Coming from Different Production Batches

2015 ◽  
Vol 244 ◽  
pp. 140-145 ◽  
Author(s):  
Matej Špak ◽  
Pavel Raschman
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Construction Materials ◽  
Chemical Properties ◽  
Raw Material ◽  
Fly Ashes ◽  
Coal Burning ◽  
Alkali Solutions ◽  
One Year ◽  
Alkali Activated

Fly ash is a well utilizable secondary raw material for the production of alkali activated construction materials. It is a significant alumina-silicates source suitable for the chemical reaction resulting in hardened composites. Physical and chemical properties of fly ashes as a co-product of coal burning mainly depend on characteristics of coal, burning temperature and combustion conditions. High variability of the properties of fly ash causes an uncertainty in the properties of alkali activated mortars. Time behaviour of the composition of the fly ash produced in a heating plant located in Košice, Slovakia as well as leaching behaviour of both alumina and silica from particular batches during one-year period was documented. Leaching tests were carried out using the distilled water and alkali solutions with three different concentrations. Both compressive and tensile strengths of alkali activated mortars were measured, and the correlation between the mechanical properties of hardened mortars and the chemical composition of fly ashes as well as their leaching characteristics was investigated.

scholarly journals Mix Design and Mechanical Properties of Fly Ash and GGBFS-Synthesized Alkali-Activated Concrete (AAC)

2019 ◽  
Vol 4 (2) ◽  
pp. 20 ◽  
Author(s):  
Ramamohana Reddy Bellum ◽  
Ruben Nerella ◽  
Sri Rama Chand Madduru ◽  
Chandra Sekhar Reddy Indukuri
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Raw Materials ◽  
Construction Materials ◽  
Xrd Analysis ◽  
Mix Design ◽  
Geopolymer Concrete ◽  
Curing Conditions ◽  
Factors Affecting ◽  
Alkali Activated

Cement is one of the construction materials widely used around the world in order to develop infrastructure and it is also one of the factors affecting economies. The production of cement consumes a lot of raw materials like limestone, which releases CO2 into the atmosphere and thus leads to global warming. Many investigations are underway in this area, essentially focusing on the eco-accommodating environment. In the research, an alternative material to cement binder is geopolymer binder, with the same efficiency. This paper presents scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis of factory byproducts (i.e., fly ash and ground granulated blast furnace slag (GGBFS)). The mix design process for the manufacture of alkali-activated geopolymer binders synthesized by fly ash and GGBFS is presented. The mechanical properties (compression, split tensile and flexural strength, bond strength) of geopolymer concrete at different mix proportions and at dissimilar curing conditions were also investigated. Geopolymer concrete synthesized with 30% fly ash and 70% GGBFS has better properties at 14 M of NaOH and cured in an oven for 24 h at 70 °C.

Development of Fly Ash-Based Geopolymer Lightweight Bricks Using Foaming Agent - A Review

2015 ◽  
Vol 660 ◽  
pp. 9-16 ◽  
Author(s):  
Wan Mastura Wan Ibrahim ◽  
Kamarudin Hussin ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Aeslina Abdul Kadir ◽  
Mohammed Binhussain
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Building Material ◽  
Raw Materials ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
Foaming Agent ◽  
Positive Effects ◽  
The World ◽  
Great Development

Bricks are widely used as a construction and building material due to its properties. Recent years have seen a great development in new types of inorganic cementitious binders called ‘‘geopolymeric cement’’ around the world. This prompted its use in bricks, which improves the greenness of ordinary bricks. The development of fly ash-based geopolymer lightweight bricks is relatively new in the field of construction materials. This paper reviews the uses of fly ash as a raw materials and addition of foaming agent to the geopolymeric mixture to produce lightweight bricks. The effects on their physical and mechanical properties have been discussed. Most manufactured bricks with incorporation of foaming agent have shown positive effects by producing lightweight bricks, increased porosity and improved the thermal conductivities of fly ash-based geopolymer bricks. However, less of performances in number of cases in terms of mechanical properties were also demonstrated.

scholarly journals Mechanical properties of alkali activated geopolymer paste using different Romanian fly ash sources – experimental results

2019 ◽  
Vol 289 ◽  
pp. 11001 ◽  
Author(s):  
Adrian Lăzărescu ◽  
Călin Mircea ◽  
Henriette Szilagyi ◽  
Cornelia Baeră
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Production Control ◽  
Experimental Results ◽  
Activation Process ◽  
Geopolymer Concrete ◽  
Alkaline Activation ◽  
Concrete Production ◽  
Specific Reactions ◽  
Alkali Activated

As concrete demand is constantly increasing in recent years and also considering that cement production is both a consumer of natural resources and a source of carbon dioxide release into the atmosphere, there have been worldwide investigations into green alternatives for making concrete environmentally friendlier and simultaneously to satisfy the development of infrastructure facilities. The use of fly ash as a component of cementitious binders is not new but when considering the specific case of alkaline activation and fly ash representing the only source for the binder formation, it necessitates a more complete understanding of its specific reactions during the alkaline activation process. Since the fly ash varies dramatically, not only from one source to another, but also from one batch to another even when provided by the same power plant, its chemistry in obtaining alkali-activated materials during the geopolymerisation process and the final mechanical properties are considered crucial for the performance of geopolymer concrete. This paper will provide a review of the experimental results concerning the physical and mechanical evaluation of the alkali-activated fly ash-based geopolymer materials, developed with different types of fly ash, for a better understanding of geopolymer concrete production control.

Recycling of Fly Ash as an Energy Efficient Building Material: A Sustainable Approach

2016 ◽  
Vol 692 ◽  
pp. 54-65
Author(s):  
Mohammad Arif Kamal
Keyword(s):  
Fly Ash ◽  
Building Material ◽  
Power Plants ◽  
Building Materials ◽  
Construction Material ◽  
Thermal Power ◽  
Raw Material ◽  
Geopolymer Concrete ◽  
Promising Alternative ◽  
Resource Material

Fly Ash, known for its proven stability for variety of applications as admixture in cement, concrete, mortar, lime pozzolan mixture (bricks. blocks) etc, is an industrial by-product from Thermal Power Plants with current annual generation of approximately 108 million tones. Fly Ash is not just environment friendly, but is known for its cost effectiveness as well. Its use as a building material helps increase buildings strength and stability. Fly Ash is believed to be a very promising alternative for the industry seeking to meet its development objectives. Fly Ash is being very effectively and economically used in building components such as bricks, doors, door-frames, etc. Fly Ash is also being used in construction of roads and embankments with some design changes. It is also used as raw material in agricultural and wasteland development programmes. The trend is clear, Fly Ash will soon be considered as a resource material and its potential will be fully exploited. Through development & application of technologies, Fly Ash has shifted from “Waste Material” category to “Resource Material” category. The purpose of this paper is to provide an overview of disposal and utilization of Fly Ash and its beneficial potential in application of civil engineering construction as well as others. The focus of this paper is to explore the properties of fly ash as building materials and also aims at the properties of geopolymer concrete, how these distinguish from general characteristics of ordinary Portland cement. It also lay emphasize on durability, properties of fly ash based geopolymer concrete and its advantage when used as a construction material as well.

Discussion on Properties and Microstructure of Geopolymer Concrete Containing Fly Ash and Recycled Aggregate

2012 ◽  
Vol 450-451 ◽  
pp. 1577-1583 ◽  
Author(s):  
Xiao Shuang Shi ◽  
Qing Yuan Wang ◽  
Xiao Ling Zhao ◽  
Frank Collins
Keyword(s):  
Fly Ash ◽  
Carbon Dioxide Emission ◽  
Construction Materials ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Strength Development ◽  
Geopolymer Concrete ◽  
Ordinary Concrete ◽  
Alkali Activated

Construction materials dominate the main responsibility to maintain the environmental sustainable development in human’s activities. Geopolymer concrete containing fly ash and recycled aggregate is a new concrete which can reuse the by-product of power station and waste concrete, as well as reduce the production of cement which contribute a lot of carbon dioxide emission in the manufacturing process. In this paper, experiments were carried out to investigate the mechanical properties and microstructure of geopolymer concrete with different recycled aggregate contents. Six mixtures were designed including alkali-activated fly ash geopolymeric recycled concrete and corresponding ordinary concrete as the comparison. The compressive strength of the concrete with 0%, 50% and 100% recycled aggregates was tested. The microstructure of these concrete were investigated by petrographic microscope under transmit light. According to experimental results, the strength development and failure mechanism are discussed. Furthermore, the application of such geopolymer concrete is discussed and suggested.

Mechanical Properties of Alkali Activated Fly Ash Geopolymer Stabilized Expansive Clay

2019 ◽  
Vol 23 (9) ◽  
pp. 3875-3888 ◽  
Author(s):  
Anant Lal Murmu ◽  
Anamika Jain ◽  
Anjan Patel
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Expansive Clay ◽  
Alkali Activated

scholarly journals Assessment of the Rheological and Mechanical Properties of Geopolymer Concrete Comprising Fly Ash and Fluid Catalytic Cracking Residue as Aluminosilicate Precursor

2021 ◽  
Vol 11 (7) ◽  
pp. 3032
Author(s):  
Tuan Anh Le ◽  
Sinh Hoang Le ◽  
Thuy Ninh Nguyen ◽  
Khoa Tan Nguyen
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
Flexural Strength ◽  
Catalytic Cracking ◽  
Fluid Catalytic Cracking ◽  
High Alumina ◽  
Geopolymer Concrete ◽  
Sem Images

The use of fluid catalytic cracking (FCC) by-products as aluminosilicate precursors in geopolymer binders has attracted significant interest from researchers in recent years owing to their high alumina and silica contents. Introduced in this study is the use of geopolymer concrete comprising FCC residue combined with fly ash as the requisite source of aluminosilicate. Fly ash was replaced with various FCC residue contents ranging from 0–100% by mass of binder. Results from standard testing methods showed that geopolymer concrete rheological properties such as yield stress and plastic viscosity as well as mechanical properties including compressive strength, flexural strength, and elastic modulus were affected significantly by the FCC residue content. With alkali liquid to geopolymer solid ratios (AL:GS) of 0.4 and 0.5, a reduction in compressive and flexural strength was observed in the case of geopolymer concrete with increasing FCC residue content. On the contrary, geopolymer concrete with increasing FCC residue content exhibited improved strength with an AL:GS ratio of 0.65. Relationships enabling estimation of geopolymer elastic modulus based on compressive strength were investigated. Scanning electron microscope (SEM) images and X-ray diffraction (XRD) patterns revealed that the final product from the geopolymerization process consisting of FCC residue was similar to fly ash-based geopolymer concrete. These observations highlight the potential of FCC residue as an aluminosilicate source for geopolymer products.

scholarly journals Effect of Elevated Temperature on Mechanical Properties of High-Volume Fly Ash-Based Geopolymer Concrete, Mortar and Paste Cured at Room Temperature

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1473
Author(s):  
Jun Zhao ◽  
Kang Wang ◽  
Shuaibin Wang ◽  
Zike Wang ◽  
Zhaohui Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Residual Strength ◽  
Elevated Temperatures ◽  
High Volume ◽  
Sem Analysis ◽  
Geopolymer Concrete ◽  
Ordinary Concrete ◽  
Exposure Temperature

This paper presents results from experimental work on mechanical properties of geopolymer concrete, mortar and paste prepared using fly ash and blended slag. Compressive strength, splitting tensile strength and flexural strength tests were conducted on large sets of geopolymer and ordinary concrete, mortar and paste after exposure to elevated temperatures. From Thermogravimetric analyzer (TGA), X-ray diffraction (XRD), Scanning electron microscope (SEM) test results, the geopolymer exhibits excellent resistance to elevated temperature. Compressive strengths of C30, C40 and C50 geopolymer concrete, mortar and paste show incremental improvement then followed by a gradual reduction, and finally reach a relatively consistent value with an increase in exposure temperature. The higher slag content in the geopolymer reduces residual strength and the lower exposure temperature corresponding to peak residual strength. Resistance to elevated temperature of C40 geopolymer concrete, mortar and paste is better than that of ordinary concrete, mortar and paste at the same grade. XRD, TGA and SEM analysis suggests that the heat resistance of C–S–H produced using slag is lower than that of sulphoaluminate gel (quartz and mullite, etc.) produced using fly ash. This facilitates degradation of C30, C40 and C50 geopolymer after exposure to elevated temperatures.

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