scholarly journals The Effect of Red Mud Content on the Compressive Strength of Geopolymers under Different Curing Systems

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 298
Author(s):  
Tao Ai ◽  
Danni Zhong ◽  
Yao Zhang ◽  
Jingshan Zong ◽  
Xin Yan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Low Temperature ◽  
Red Mud ◽  
Room Temperature ◽  
Xrd Analysis ◽  
Dense Structure ◽  
Curing Conditions ◽  
Higher Temperature

To maximize the utilization of red mud in geopolymers, a red mud–metakaolin (RM-MK) geopolymer and red mud–fly ash (RM-FA) geopolymer were prepared, respectively. The effects of red mud content on the compressive strength and microstructure of the geopolymers were investigated under three different curing conditions. The results showed that the strength of the geopolymer decreased linearly with an increase in the red mud content, whether curing at room temperature or 80 °C. Surprisingly, curing in an autoclave, the appropriate amount of red mud had a favorable impact on the mechanical properties of the geopolymers. When the amount of red mud was 50%, the strength of the RM-MK geopolymer reached its highest compressive strength, 36.3 MPa, and the strength of the RM-FA geopolymer reached its highest at 31.7 MPa. Compared with curing at low temperature, curing the red mud-based geopolymers under a higher temperature and higher pressure can maximize the use of red mud. XRD analysis indicated that zeolite minerals formed. The SEM results showed that the geopolymers cured in an autoclave had a dense structure.

Comparison of Using NaOH and KOH Activated Fly Ash-Based Geopolymer on the Mechanical Properties

2014 ◽  
Vol 803 ◽  
pp. 179-184 ◽  
Author(s):  
R.H. Abdul Rahim ◽  
Tia Rahmiati ◽  
Khairun Azizi Azizli ◽  
Zakaria Man ◽  
Mohd Fadhil Nuruddin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Potassium Hydroxide ◽  
Room Temperature ◽  
Silicate Solution ◽  
Source Material ◽  
Sodium Potassium ◽  
Curing Conditions

Geopolymer synthesis has two main requirements to fulfil which are the source material that is rich in Silicon (Si) and Aluminum (Al) and alkali activator such as sodium/potassium hydroxide. Sodium hydroxide (NaOH) is widely used for the synthesis of geopolymer compared to potassium hydroxide (KOH) with addition of silicate solution for the purpose of increasing dissolution process. However, the comparison of using different activator in the absence of silicate solution for geopolymer synthesis is not well established. This paper presents an evaluation on compressive strength of fly ash–based geopolymer by using different activator (KOH and NaOH) with respect to different curing conditions (time and temperature) in the absence of sodium silicate. The samples were mixed using mortar mixer and prepared in 50mm x 50mm x 50mm mould for determination of compressive strength. It can be observed that the highest compressive strength up 65.28 MPa was obtained using NaOH. Meanwhile, synthesis using KOH only recorded 28.73 MPa. The compressive strength was better when cured at elevated temperature (60°C) than room temperature (25°C). Further analysis on the microstructure of the highest compressive strength geopolymer samples for both activators was carried out using Field Emission Scanning Microscopy (FESEM) and Raman spectroscopy.

scholarly journals Low-temperature degradation resistance and plastic deformation of ATZ ceramics stabilized by CaO

2021 ◽  
Vol 2103 (1) ◽  
pp. 012075
Author(s):  
AA Dmitrievskiy ◽  
DG Zhigacheva ◽  
VM Vasyukov ◽  
PN Ovchinnikov
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Plastic Deformation ◽  
Compressive Strength ◽  
Phase Composition ◽  
Low Temperature ◽  
Uniaxial Compression ◽  
Calcium Oxide ◽  
Tetragonal Phase ◽  
Room Temperature

Abstract In this work, the phase composition (relative fractions of monoclinic m-ZrO2, tetragonal t-ZrO2, and cubic c-ZrO2 phases) and mechanical properties (hardness, fracture toughness, compressive strength) of alumina toughened zirconia (ATZ) ceramics, with an addition of silica were investigated. Calcium oxide was used as a stabilizer for the zirconia tetragonal phase. It was shown that CaO-ATZ+SiO2 ceramics demonstrate increased resistance to low-temperature degradation. The plasticity signs at room temperature were found due to the SiO2 addition to CaO-ATZ ceramics. A yield plateau appears in the uniaxial compression diagram at 5 mol. % SiO2 concentration. It is hypothesized that discovered plasticity is due to the increased t→m transformability.

Influence of Variable Temperature Curing on Mechanical Properties of Fly Ash Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 178-181
Author(s):  
Ya Ding Zhao ◽  
Xue Ying Li ◽  
Ling Chao Kong ◽  
Wei Du
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Fly Ash ◽  
Flexural Strength ◽  
Variable Temperature ◽  
Improve Performance ◽  
Curing Conditions ◽  
Fly Ash Concrete ◽  
Better Than

Under variable temperature curing conditions(30 oC ~70 oC), concrete with fly ash whose compressive strength, flexural strength, and dynamic elastic modulus are better than ones without fly ash.Compared with constant temperature 20oC, 50 oC and 70 oC, variable temperature curing(VTC) is benefit for the improvement of mechanical properties of 30% fly ash concrete, but which is no advantage to improve performance of 50% fly ash concrete.

Fly Ash Based Lightweight Geopolymer Concrete Using Foaming Agent Technology

2014 ◽  
Vol 679 ◽  
pp. 20-24 ◽  
Author(s):  
Mohd Mustafa Al Bakri Abdullah ◽  
Zarina Yahya ◽  
Muhammad Faheem Mohd Tahir ◽  
Kamarudin Hussin ◽  
Mohammed Binhussain ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Room Temperature ◽  
Lightweight Concrete ◽  
Agent Technology ◽  
Alkali Activation ◽  
Geopolymer Concrete ◽  
Foaming Agent ◽  
Curing Conditions ◽  
Foam Generator

This paper presents the mechanical properties of a lightweight geopolymer concrete synthesized by the alkali-activation of a fly ash source (FA) produced by mixing a paste of geopolymer with foam produced by using NCT Foam Generator. Two curing conditions are used, curing at room temperature and curing in an oven with a constant temperature which is 60 oC. Bulk density showed that fly ash-based geopolymer lightweight concrete is light with the density of 1225 kg/m3 - 1667 kg/m3 with an acceptable compressive strength of 17.60 MPa for the density of 1667 kg/m3.

The Effect of Fly Ash and Red Mud Content on the Compressive Strength of Foam Concrete

2011 ◽  
Vol 374-377 ◽  
pp. 1523-1526 ◽  
Author(s):  
Fan Wang ◽  
Yi He Zhang ◽  
Tong Zhao ◽  
An Zhen Zhang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Red Mud ◽  
Foam Concrete ◽  
Curing Conditions ◽  
Different Content

A series of foam concrete with different content of fly ash or red mud were experimentally investigated in this study. The results indicated that the water-solids ratio of optimized material proportion and curing conditions were 0.5, and the compressive strength and density of the concrete compressive would fall with the addition of fly ash or red mud.

scholarly journals An Experimental Investigation of the Stress-Strain Behaviour of Geopolymer Concrete

2018 ◽  
Vol 26 (2) ◽  
pp. 30-34 ◽  
Author(s):  
M. Venu ◽  
T. D. Gunneswara Rao
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Modulus Of Elasticity ◽  
Geopolymer Concrete ◽  
Test Results ◽  
Stress Strain ◽  
Curing Conditions ◽  
Strain Behaviour ◽  
Measured Stress

AbstractThis paper focuses on the mechanical properties and modulus of elasticity of fly ash and GGBS based geopolymer concrete. In this study an 8 molarity concentration of NaOH and alkaline liquid ratio in a ratio of 2.5 was used. This study includes the stress-strain behaviour along with the flexural strength, compressive strength and split tensile strengths for the GPC20, GPC40 and GPC60 grades. Tests were carried out on 150 mm × 150 mm × 150 mm cubes and 100 × 100 × 500 mm prisms and 150 × 300 mm cylindrical geopolymer concrete specimens. The test results not- ed the good mechanical properties and measured stress-strain relations of fly ash and GGBS based geopolymer concrete under ambient curing conditions. The elastic modulus was significantly varied with increases in the grade of the concrete. An equation was proposed to determine the modulus of elasticity based on the compressive strength of the geopolymer concrete.

The Mechanical Properties and Thermal Resistance of Fly Ash Geopolymer Foams

2018 ◽  
Vol 281 ◽  
pp. 175-181
Author(s):  
Hui Teng Ng ◽  
Cheng Yong Heah ◽  
Yun Ming Liew ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Peroxide ◽  
Compressive Strength ◽  
High Temperature ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Thermal Resistance ◽  
Bulk Density ◽  
Room Temperature ◽  
Heating Up

In the present work, a comparative study of the thermal performance of unfoamed and foamed geopolymers was investigated. The geopolymers were prepared by mixing fly ash with alkali activator (a mixture of sodium hydroxide and sodium silicate). The geopolymer foams were prepared by adding hydrogen peroxide (H2O2, 2wt.% and 4wt.%). The geopolymers were cured at room temperature (29°C) for 24 hours and at 60°C for another 24 hours. The bulk density and compressive strength decreased with increasing H2O2 up to 2wt.% and increased when 4wt.% of H2O2 was added. In order to test the thermal resistance, the geopolymers were heated at elevated temperature (200- 1000°C). Unheated geopolymers showed bulk density and compressive strength in the range of 1.6– 1.7g/cm3 and 15–17MPa, respectively. When heated up to 1000°C, the geopolymers could withstand high temperature without any disintegration and spalling. Both unfoamed and foamed geopolymers showed highest compressive strength at 200°C (17–22MPa). Further decreased in compressive strength was observed upon heating up to 800°C (10–17MPa). The compressive strength regained (14–21MPa) when heated up to 1000°C. The compressive strength was even higher than that recorded at room temperature. In the present work, unfoamed geopolymers showed overall higher thermal resistance than foamed geopolymers.

The Influence of Curing Conditions on the Physical and Mechanical Properties of Magnesia Phosphate Cements

2008 ◽  
Vol 59 (2) ◽  
pp. 135-139 ◽  
Author(s):  
Jenica Paceagiu ◽  
Maria Georgescu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Variable Temperature ◽  
Physical And Mechanical Properties ◽  
Reaction Products ◽  
Phosphate Binding ◽  
Curing Conditions ◽  
Weight Variation ◽  
Chemical Solutions

The paper brings information on the influence of curing conditions such as humidity, variable temperature and chemical solutions, on the compressive strength and weight variation of the magnesia phosphate binding materials, obtained from magnesite, mono-ammonia phosphate, borax and sand having a granulation ranging between 0.1-1 mm, with or without fly ash addition. The XRD and SEM�EDX analysis were made for obtaining information concerning the reaction products formed in phosphate magnesia binding materials cured in conditions of variable humidity.

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.

scholarly journals Mechanical Behavior of Brick Masonry in an Acidic Atmospheric Environment

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2694 ◽  
Author(s):  
Shansuo Zheng ◽  
Lihua Niu ◽  
Pei Pei ◽  
Jinqi Dong
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Acid Rain ◽  
Cement Mortar ◽  
Brick Masonry ◽  
Atmospheric Environment ◽  
Peak Strain ◽  
Lime Mortar ◽  
Attenuation Model

In order to evaluate the deterioration regularity for the mechanical properties of brick masonry due to acid rain corrosion, a series of mechanical property tests for mortars, bricks, shear prisms, and compressive prisms after acid rain corrosion were conducted. The apparent morphology and the compressive strength of the masonry materials (cement mortar, cement-lime mortar, cement-fly ash mortar, and brick), the shear behavior of the masonry, and the compression behavior of the masonry were analyzed. The resistance of acid rain corrosion for the cement-lime mortar prisms was the worst, and the incorporation of fly ash into the cement mortar did not improve the acid rain corrosion resistance. The effect of the acid rain corrosion damage on the mechanical properties for the brick was significant. With an increasing number of acid rain corrosion cycles, the compressive strength of the mortar prisms, and the shear and compressive strengths of the brick masonry first increased and then decreased. The peak stress first increased and then decreased whereas the peak strain gradually increased. The slope of the stress-strain curve for the compression prisms gradually decreased. Furthermore, a mathematical degradation model for the compressive strength of the masonry material (cement mortar, cement-lime mortar, cement-fly ash mortar, and brick), as well as the shear strength attenuation model and the compressive strength attenuation model of brick masonry after acid rain corrosion were proposed.

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