scholarly journals Life-Cycle Assessment of Fly Ash and Cenosphere-Based Geopolymer Material

2021 ◽  
Vol 13 (20) ◽  
pp. 11167
Author(s):  
Weixin Tang ◽  
Gloria Pignatta ◽  
Samad M. E. Sepasgozar
Keyword(s):  
Compressive Strength ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Fly Ash ◽  
Flexural Strength ◽  
Industrial Waste ◽  
Waste Treatment ◽  
Transport Modelling ◽  
Production Scale ◽  
Key Factor

It was widely reported in the early 2000s that geopolymer technology exhibits superior mechanical properties and lower global warming potential (GWP) over the use of ordinary Portland cement (OPC). However, a major limitation observed in the sustainability evaluation is a lack of consideration of environmental impacts from the use of industrial waste. This observation led to the purpose of this study, which is to identify the key factors throughout geopolymer production that contribute to its sustainability performance. In this paper, two geopolymers made of fly ash (G-FA) and cenospheres (G-C) were examined by mechanical testing while their sustainability impacts on a cradle-to-grave approach were investigated. The industrial waste and transport modelling impacts were given special attention in the performed life-cycle assessment. After 28 days of curing, G-FA exhibited 64.56 MPa and 6.03 MPa of compressive strength and flexural strength, respectively. G-C, with ¾ of G-FA bulk density, achieved 19.09 MPa and 3.13 MPa, respectively, with no significant changes observed after 14 days of curing. By upscaling the inventories to 1 m3 of industrial production scale, geopolymers showed a GWP reduction up to 49.7% compared to OPC with natural aggregates and presented benefits on human health damage category by 23.7% (G-FA) to 41.6% (G-C). In conclusion, geopolymer mortars establish compressive strength and flexural strength that are adequate for construction applications and present sustainability benefits in GWP, which suggests them to be potential substitutions for OPC. However, the industrial waste treatment (i.e., preparation of fly ash) will deplete water bodies, and the sodium silicate induces significant environmental burdens during its manufacture, becoming the key factor to enhance the geopolymer’s sustainability.

scholarly journals Life Cycle Assessment and Impact Correlation Analysis of Fly Ash Geopolymer Concrete

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7375
Author(s):  
Xiaoshuang Shi ◽  
Cong Zhang ◽  
Yongchen Liang ◽  
Jinqian Luo ◽  
Xiaoqi Wang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Co2 Emissions ◽  
Co2 Emission ◽  
Gray Relational Analysis ◽  
Geopolymer Concrete ◽  
Sodium Hydroxide Concentration

Geopolymer concrete (GPC) has drawn widespread attention as a universally accepted ideal green material to improve environmental conditions in recent years. The present study systematically quantifies and compares the environmental impact of fly ash GPC and ordinary Portland cement (OPC) concrete under different strength grades by conducting life cycle assessment (LCA). The alkali activator solution to fly ash ratio (S/F), sodium hydroxide concentration (CNaOH), and sodium silicate to sodium hydroxide ratio (SS/SH) were further used as three key parameters to consider their sensitivity to strength and CO2 emissions. The correlation and influence rules were analyzed by Multivariate Analysis of Variance (MANOVA) and Gray Relational Analysis (GRA). The results indicated that the CO2 emission of GPC can be reduced by 62.73%, and the correlation between CO2 emission and compressive strength is not significant for GPC. The degree of influence of the three factors on the compressive strength is CNaOH (66.5%) > SS/SH (20.7%) > S/F (9%) and on CO2 emissions is S/F (87.2%) > SS/SH (10.3%) > CNaOH (2.4%). Fly ash GPC effectively controls the environmental deterioration without compromising its compressive strength; in fact, it even in favor.

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.

Life cycle assessment and cost analysis of fly ash–rice husk ash blended alkali-activated concrete

2021 ◽  
Vol 295 ◽  
pp. 113140
Author(s):  
Sarah Fernando ◽  
Chamila Gunasekara ◽  
David W. Law ◽  
M.C.M. Nasvi ◽  
Sujeeva Setunge ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Fly Ash ◽  
Cost Analysis ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Alkali Activated Concrete ◽  
Alkali Activated

scholarly journals Strength Time–Varying and Freeze–Thaw Durability of Sustainable Pervious Concrete Pavement Material Containing Waste Fly Ash

2018 ◽  
Vol 11 (1) ◽  
pp. 176 ◽  
Author(s):  
Hanbing Liu ◽  
Guobao Luo ◽  
Longhui Wang ◽  
Yafeng Gong
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Pervious Concrete ◽  
Early Age ◽  
Pavement Materials ◽  
Freeze Thaw ◽  
Replacement Method ◽  
Porosity And Permeability ◽  
Volume Method

Pervious concretes, as sustainable pavement materials, have great advantages in addressing a number of environmental issues. Fly ash, as the industrial by-product waste, is the most commonly used as cement substitute in concrete. The objective of this paper is to study the effects of waste fly ash on properties of pervious concrete. Fly ash was used to replace cement with equivalent volume method at different levels (3%, 6%, 9%, and 12%). The control pervious concrete and fly ash modified pervious concrete were prepared in the laboratory. The porosity, permeability, compressive strength, flexural strength, and freeze–thaw resistance of all mixtures were tested. The results indicated that the addition of fly ash decreased the early-age (28 d) compressive strength and flexural strength, but the long-term (150 d) compressive strength and flexural strength of fly ash modified pervious concrete were higher than that of the early-age. The adverse effect of fly ash on freeze–thaw resistance of pervious concrete was observed when the fly ash was added. The porosity and permeability of all pervious concrete mixtures changed little with the content of fly ash due to the use of equal volume replacement method. Although fly ash is not positive to the properties of pervious concrete, it is still feasible to apply fly ash as a substitute for cement in pervious concrete.

scholarly journals Kajian Karakteristik Beton Memadat Sendiri yang Menggunakan Serat Ijuk (Hal. 54-65)

2018 ◽  
Vol 4 (4) ◽  
pp. 54
Author(s):  
Iis Nurjamilah ◽  
Abinhot Sihotang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Coarse Aggregate ◽  
Fresh Concrete ◽  
High Strength ◽  
Self Compacting Concrete ◽  
Palm Fiber ◽  
Fiber Concrete ◽  
Dilute Mixture

ABSTRAKKajian karakteristik beton memadat sendiri yang menggunakan serat ijuk merupakan sebuah kajian yang dilakukan untuk mengetahui pengaruh penambahan serat ijuk terhadap karakteristik beton memadat sendiri (SCC). Beton memadat sendiri yang menggunakan serat ijuk (PFSCC) didesain memiliki campuran yang encer, bermutu tinggi (= 40 MPa) dan memiliki persentase kekuatan lentur yang lebih baik. PFSCC  didapatkan dari hasil pencampuran antara semen sebanyak 85%, fly ash 15%, superplastizicer 1,5%, serat ijuk 0%, 0,5%; 1%; 1,5%; 2% dan 3% dari berat binder (semen + fly ash), kadar air 190 kg/m3, agregat kasar 552,47 kg/m3 dan pasir 1.063 kg/m3. Semakin banyak persentase penambahan serat ijuk ke dalam campuran berdampak terhadap menurunnya workability beton segar. Penambahan serat ijuk yang paling baik adalah sebanyak 1%, penambahan tersebut dapat meningkatkan kekuatan tekan beton sebesar 13% dan lentur sebesar 1,8%.Kata kunci: beton memadat sendiri (SCC), beton berserat, beton memadat sendiri yang menggunakan serat ijuk (PFSCC), serat ijuk ABSTRACTThe study of characteristics self compacting concrete using palm fibers is a study conducted to determine the effect of adding palm fibers to characteristics of self compacting concrete (SCC). palm fibers self compacting concrete (PFSCC) is designed to have a dilute mixture, high strength (= 40 MPa), and have better precentage flexural strength. PFSCC was obtained from mixing of 85% cement, 15% fly ash, 1.5% superplastizicer, 0%, 0.5%, 1%, 1.5%, 2% and 3% palm fibers from the weight of binder  (cement + fly ash), water content 190 kg/m3, coarse aggregate 552.47 kg/m3 and sand 1,063 kg/m3. The more persentage palm fibers content added to the mixture makes workability of fresh concrete decreases. The best addition of palm fiber is 1%, this addition can increases the compressive strength 13% and flexural strength 1.8%.Keywords: self compacting concrete (SCC), fiber concrete, Palm fiber self compacting concrete (PFSCC), palm fiber

scholarly journals Environmental impacts of a hydrometallurgical process for electronic waste treatment: A life cycle assessment case study

2017 ◽  
Vol 140 ◽  
pp. 1204-1216 ◽  
Author(s):  
Elena Maria Iannicelli-Zubiani ◽  
Martina Irene Giani ◽  
Francesca Recanati ◽  
Giovanni Dotelli ◽  
Stefano Puricelli ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impacts ◽  
Waste Treatment ◽  
Electronic Waste ◽  
Hydrometallurgical Process

scholarly journals Strength Characteristics of High Strength Concrete (HSC) with and without Coarse Aggregate

2019 ◽  
Vol 9 (2) ◽  
pp. 4701-4704
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Silica Fume ◽  
High Strength Concrete ◽  
Mechanical Characteristics ◽  
Coarse Aggregate ◽  
High Strength ◽  
Set Up

This paper aimed to investigate the mechanical characteristics of HSC of M60 concrete adding 25% of fly ash to cement and sand and percentage variations of silica fumes 0%,5% and 10% to cement with varying sizes of 10mm,6mm,2mm and powder of granite aggregate with w/c of 0.32. Specimens are tested for compressive strength using 10cm X 10cmX10cm cubes for 7,14,28 days flexural strength was determined by using 10cmX10cmX50cm beam specimens at 28 days and 15cm diameter and 30cm height cylinder specimens at 28 days using super plasticizers of conplast 430 as a water reducing agent. In this paper the experimental set up is made to study the mechanical properties of HSC with and without coarse aggregate with varying sizes as 10mm, 6mm, 2mm and powder. Similarly, the effect of silica fume on HSC by varying its percentages as 0%, 5% and 10% in the mix studied. For all mixes 25% extra fly ash has been added for cement and sand.

UTILIZATION OF FLY ASH AND CONCRETE RESIDUE IN THE PRODUCTION OF GEOPOLYMER BRICKS

2017 ◽  
Vol 12 (1) ◽  
pp. 63-77 ◽  
Author(s):  
Siriporn Sirikingkaew ◽  
Nuta Supakata
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Compressive Strength ◽  
Phase Composition ◽  
Fly Ash ◽  
Industrial Waste ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

This study presents the development of geopolymer bricks synthetized from industrial waste, including fly ash mixed with concrete residue containing aluminosilicate compound. The above two ingredients are mixed according to five ratios: 100:0, 95:5, 90:10, 85:15, and 80:20. The mixture's physico-mechanical properties, in terms of water absorption and the compressive strength of the geopolymer bricks, are investigated according to the TIS 168-2546 standard. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses are used to investigate the microstructure and the elemental and phase composition of the brick specimens. The results indicate that the combination of fly ash and concrete residue represents a suitable approach to brick production, as required by the TIS 168–2546 standard.

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