The Use of Recycled Aggregate Sludge for the Preparation of GGBFS and Fly Ash Based Geopolymer

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1486
Author(s):  
Yi-Chen Chen ◽  
Wei-Hao Lee ◽  
Yung-Chin Ding
Keyword(s):  
Fly Ash ◽  
Environmental Concern ◽  
Waste Product ◽  
Recycled Aggregate ◽  
Test Results ◽  
Granulated Blast Furnace Slag ◽  
Mechanical And Physical Properties ◽  
Preliminary Study ◽  
Solid Liquid ◽  
High Treatment

Aggregate sludge is a waste product produced from crushing, screening, and washing processes at aggregate plants. Because of the large quantity and high treatment cost of this sludge, it cannot be disposed of as landfill, and thus, has caused environmental concern over the years in Taiwan. In this preliminary study, the recycled aggregate sludge was reutilized for construction applications through the geopolymerization process. The ground granulated blast furnace slag (GGBFS) and fly ash (FA) were selected as alkaline activated materials for the fabrication of sludge geopolymer. Several process parameters that may affect the mechanical and physical properties of geopolymer were investigated. These parameters are sludge/GGBFS/FA ratios, solid/liquid (alkali solution) ratio, the molarity of NaOH, and curing time. According to the test results, the compressive strength of geopolymer specimens (70/30 sludge/GGBFS ratios) made with 4 M and 6 M NaOH can reach 39.17 MPa and 43.6 MPa after 28 days of curing. The specimen made with 60/40 sludge/GGBFS ratios has a strength of 61.3 MPa. After replacing GGBFS with 10% fly ash (70/20/10 sludge/GGBFS/FA), the strength of the specimen can also reach 43 MPa. According to the test results obtained in this study, it was found that the higher the NaOH concentration, the higher the strength of the geopolymer, and the GGBFS also can contribute more to the mechanical properties of geopolymer than fly ash. This preliminary study suggests that it is possible to reutilize aggregate sludge for construction applications and solve its environmental disposal problem.

scholarly journals Effect of Mineral Admixtures on the Performance of Low-Quality Recycled Aggregate Concrete

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 596
Author(s):  
Yasuhiro Dosho
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Mineral Admixtures ◽  
Structural Concrete ◽  
Aggregate Concrete ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

To improve the application of low-quality aggregates in structural concrete, this study investigated the effect of multi-purpose mineral admixtures, such as fly ash and ground granulated blast-furnace slag, on the performance of concrete. Accordingly, the primary performance of low-quality recycled aggregate concrete could be improved by varying the replacement ratio of the recycled aggregate and using appropriate mineral admixtures such as fly ash and ground granulated blast-furnace slag. The results show the potential for the use of low-quality aggregate in structural concrete.

scholarly journals A Preliminary Study on the Physical Properties of an Alternative Coarse Aggregate Made with Red Soil and Fly Ash

2018 ◽  
Vol 12 (1) ◽  
pp. 1-8
Author(s):  
J. Bright Brabin Winsley ◽  
M. Muthukannan
Keyword(s):  
Fly Ash ◽  
Specific Gravity ◽  
Room Temperature ◽  
Coarse Aggregate ◽  
Environmental Issues ◽  
Red Soil ◽  
Test Results ◽  
Ordinary Concrete ◽  
Preliminary Study ◽  
Natural Aggregates

Background and Objective: The demand for course aggregate is increasing every day. Natural aggregate used for ordinary concrete is obtained by quarrying, which cause serious environmental issues. An alternate course aggregate is needed for sustainable development. The objective of this research is to produce an alternative course aggregate in combination with soil available locally near site along with fly ash, to test its properties to make it fit for concrete. Method: An alternative coarse aggregate is produced from red soil and fly ash mixed at various ratios, 100:0, 90:10, 80:20, 70:30, 60:40, 50:50, fresh aggregate granules of different sizes less than 10mm is prepared using hand press, the aggregates were sundried in shade for 24hours, oven dried at 110°C, burned in Muffle furnace at temperature of 950°C and cooled gradually to reach room temperature. After the production, the specific gravity, bulk density, water absorption, Impact and aggregate crushing of the aggregates were tested. Result: Test results showed that aggregates produced are of lesser specific gravity, density with relatively appreciable impact value and crushing value. Conclusion: The test results show that the aggregates produced can be used in construction as replacement for natural aggregates.

Durability of Alkali-Activated Fly Ash/Slag Concrete

2017 ◽  
Vol 904 ◽  
pp. 157-161 ◽  
Author(s):  
Mao Chieh Chi ◽  
Hsian Chen ◽  
Tsai Lung Weng ◽  
Ran Huang ◽  
Yih Chang Wang
Keyword(s):  
Fly Ash ◽  
Total Charge ◽  
Test Results ◽  
Mass Ratio ◽  
Modulus Ratio ◽  
Granulated Blast Furnace Slag ◽  
Alkali Activated Binders ◽  
Furnace Slag ◽  
Alkali Activated ◽  
Better Than

This study investigated the durability of alkali-activated binders based on blends of fly ash (FA) and ground granulated blast furnace slag (GGBFS). Five fly ash-to-slag ratios of 100/0, 75/25, 50/50, 25/75, and 0/100 by mass were selected to produce alkali-activated fly ash/slag (AAFS) concrete. Sodium oxide (Na2O) concentrations of 6% and 8% of binder weight and activator modulus ratios (mass ratio of SiO2 to Na2O) of 0.8, 1.0, and 1.23 were used as alkaline activators. Test results show that the total charge passed of AAFS concrete is between 2500 and 4000 coulombs, higher than the comparable OPC concrete. However, AAFS concrete exposed to sulfate attack performed better than OPC concrete. Based on the results, 100% slag-based AAFS concrete with Na2O concentration of 8% and activator modulus ratio of 1.23 has the superior performances.

scholarly journals Strength and Durability Characteristics of Steel Fibre Reinforced Concrete with Mineral Admixtures

2019 ◽  
Vol 9 (1) ◽  
pp. 3893-3897
Keyword(s):  
Reinforced Concrete ◽  
Fly Ash ◽  
Steel Fibre ◽  
Mineral Admixtures ◽  
Fibre Reinforced Concrete ◽  
Test Results ◽  
Split Tensile Strength ◽  
Steel Fibre Reinforced Concrete ◽  
Granulated Blast Furnace Slag ◽  
Strength And Durability

The present investigation is carried out to study the strength and durability characteristics of steel fibre reinforced concrete, by replacing Ordinary Portland cement with Fly Ash, Ground Granulated Blast Furnace Slag (GGBS) and Metakaolin. In this study, cement is replaced by 30% and 40% with Fly Ash, GGBS and Metakaolin for M30 and M35 grades of concrete. Steel fibres @ 1% by weight of binder is used in all the mixes. Strength characteristics like compressive strength and split tensile strength are tested at 7 days and 28 days age. Additionally, durability tests such as water absorption and Sorptivity tests are conducted after 28days curing. The test results have shown that 30% replacement is optimum for strength criteria. And when metakaolin is used with fly ash, durability properties were improved and workability reduced.

Structural Behaviour of Ferrogeopolymer Slabs under Flexure

2016 ◽  
Vol 866 ◽  
pp. 109-113
Author(s):  
Rathinam Kumutha ◽  
Kanagarajan Vijai ◽  
P. Rajeswaran
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Mild Steel ◽  
Double Layers ◽  
Fine Aggregate ◽  
Test Results ◽  
Structural Behaviour ◽  
Granulated Blast Furnace Slag ◽  
Binder Ratio ◽  
The Individual

The main objective of this paper was to present the results of experimental investigation carried out to study the structural behaviour of ferrogeopolymer elements under flexure. Initially the properties of geopolymeric binder prepared using the source materials such as Fly ash and Ground Granulated Blast Furnace Slag (GGBS) without conventional cement have been investigated. The different parameters considered in this study are the ratio of binder to fine aggregate (1:2 and1:3) and the ratio of Na2SiO3 to NaOH solutions (2.0 and 2.5). The various combinations of Fly ash and GGBS considered are 90% & 10% and 80% & 20%. The alkaline liquid to binder ratio is fixed as 0.45. The individual properties of mortar such as Compressive Strength and Density were determined as per relevant Indian standards. The geopolymer concrete mix that gives the highest compressive strength was used to cast the ferrogeopolymer structural slabs. Four numbers of rectangular slabs of size 800 mm x 300 mm x 25 mm were prepared with two types of meshes such as mild steel and galvanized iron weld mesh with single and double layers. Based on the test results Load-Deflection curves were drawn and the effectiveness of mild steel and galvanized iron weld meshes was compared from the characteristics such as first crack load, ultimate load, energy absorption and ductility.

Durability of Sustainable Self-Consolidating Concrete

2018 ◽  
Vol 765 ◽  
pp. 285-289
Author(s):  
Osama Ahmed Mohamed ◽  
Waddah Al Hawat ◽  
Omar Fawwaz Najm
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Cementitious Materials ◽  
Chloride Penetration ◽  
Supplementary Cementitious Materials ◽  
Test Results ◽  
Self Consolidating Concrete ◽  
Human Footprint ◽  
Granulated Blast Furnace Slag

Supplementary cementitious materials such as fly ash, silica fume and ground granulated blast furnace slag (GGBS) have been used widely to partially replace cement in producing self-consolidating concrete (SCC). The production of cement is associated with emission of significant amounts of CO2 and increases the human footprint on the environment. Fly ash, silica fume, and GGBS are recycled industrial by-products that also impart favorable fresh and hardened properties on concrete. This study aims to assess the effect of the amounts of fly ash and silica fume on strength and chloride penetration resistance of concrete. Rapid Chloride Penetration Test (RCPT) was used to assess the ability of SCC to resist ingress of chlorides into concrete. SCC mixes with different dosages of fly ash and silica fume were developed and tested at different curing ages. Test results showed that replacing 20% of cement with fly ash produced the highest compressive strength of 67.96 MPa among all fly ash-cement binary mixes. Results also showed that replacing15% of cement with silica fume produced the highest compressive strength of 95.3 MPa among fly ash-cement binary mixes. Using fly ash and silica fume consistently increased the concrete resistance to chloride penetration at the early ages. Silica fume at all dosages results in low or very low levels of chloride penetration at all curing ages of concrete.

Effect of Solid to Liquid Ratio on the Mechanical and Physical Properties of Fly Ash Geopolymer without Sodium Silicate

2014 ◽  
Vol 625 ◽  
pp. 46-49 ◽  
Author(s):  
Rosniza Hanim Abdul Rahim ◽  
Khairun Azizi Azizli ◽  
Zakaria Man ◽  
Tia Rahmiati ◽  
Lukman Ismail
Keyword(s):  
Mechanical Property ◽  
Compressive Strength ◽  
Fly Ash ◽  
Physical Properties ◽  
Silicate Solution ◽  
Strength Development ◽  
Alkali Activation ◽  
Liquid Ratio ◽  
Mechanical And Physical Properties ◽  
Solid Liquid

Geopolymer is produced from the alkali activation of materials rich in Si and Al with addition of silicate solution in order to improve the mechanical property. Limited research has been done with the absence of silicate solution in the geopolymerization process by varying solid/liquid ratio and on how it works for that condition on mechanical and physical properties. This paper presents an investigation on the mechanical and physical properties of fly ash based geopolymer by varying solid to liquid ratio using sodium hydroxide as the only activator. In addition, the strength development also been investigated. The samples were prepared using 50mm x 50mm x 50mm mould and cured at an elevated temperature (60oC). It can be observed that the optimum compressive strength and density were obtained at solid/ liquid ratio of 4. In addition, the compressive strength of fly ash based geopolymer for all the solid to liquid ratio increased until 14 days and started to decrease later.

scholarly journals Salt-Frost Scaling of Concrete with Slag and Fly Ash - Influence of Carbonation and Prolonged Conditioning on Test Results

2020 ◽  
Vol 63 (2) ◽  
pp. 89-108
Author(s):  
Elisabeth Helsing ◽  
Peter Utgenannt
Keyword(s):  
Fly Ash ◽  
Frost Resistance ◽  
Test Results ◽  
Portland Cement Concrete ◽  
Supplementary Cementitious Material ◽  
Granulated Blast Furnace Slag ◽  
Binder Ratio ◽  
Swedish Experience ◽  
Entrained Air ◽  
Water To Binder Ratio

AbstractAccording to Swedish experience the slab method in CEN/TS 12390-9 is successful in predicting the salt-frost resistance of Portland cement concrete. However, doubts have been raised whether the same can be said when used on concrete with supplementary cementitious material, e.g. fly ash or ground granulated blast furnace slag (GGBS). Test results from concrete mixes with up to 35 % fly ash 65 % GGBS, with two different Portland cements and a water-to-binder ratio of 0.45 are presented in this paper. The tests were carried out with the standard method and with five modifications concerning the pre-conditioning of the specimens before freeze-thaw cycling. The age of the specimens at sawing was increased, the time in 65 % RH was prolonged and exposure to 1 % CO2-environment was used. The results show that for air-entrained concrete with fly ash or GGBS both prolonging the exposure to 65 % RH and exposure to CO2 diminishes the salt-frost resistance. The influence increases with increasing amount of fly ash or GGBS. However, the type of cement also has a certain influence. The influence of exposure to CO2 on the salt-frost resistance of concrete without entrained air was totally different from the influence on concrete with entrained air.

scholarly journals Analysis of Changes in the Microstructure of Geopolymer Mortar after Exposure to High Temperatures

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4263
Author(s):  
Marta Dudek ◽  
Mateusz Sitarz
Keyword(s):  
High Temperature ◽  
Fly Ash ◽  
High Temperatures ◽  
Test Results ◽  
Spectroscopy Analysis ◽  
Granulated Blast Furnace Slag ◽  
Current State ◽  
High Durability ◽  
Digital Microscope ◽  
Microstructure Of The Material

The inorganic structure formed at the stage of setting of the geopolymer binder ensures high durability of the material under high-temperature conditions. However, changes in the microstructure of the material are observed. The purpose of the study was to analyze changes in the structure of geopolymer mortar after exposure to high temperatures T = 200, 400, 600, 800, and 1000 °C. Mortars with a binder based solely on fly ash (FA) and mixed in the 1:1 ratio with a binder containing fly ash and ground granulated blast-furnace slag (GGBFS) were tested. The descriptions of their microstructures were prepared based on digital microscope observations, scanning electron microscope (SEM) observations, EDS (energy dispersive spectroscopy) analysis, and mercury intrusion porosimetry (MIP) porosity test results. Changes in the material due to high temperature were observed. The differences in the microstructure of the samples are also visible in the materials that were not exposed to temperature, which was influenced by the composition of the materials. Porosity increases with increasing annealing temperature. The distribution of individual pores also changes. In both materials, the proportion of pores larger than 1000 nm increases with the temperature increase. Moreover, the number of cracks and their width also increases, reaching 20 µm in the case of GGBFS. Furthermore, the color of geopolymers has changed. The obtained results extend the current state of knowledge in the field of changes in the microstructure of geopolymers subjected to high temperature.

scholarly journals An Experimental Programme on Frc with Opc, Flyash, Ggbs, and Metakaolin

2019 ◽  
Vol 8 (10) ◽  
pp. 3713-3717
Keyword(s):  
Fly Ash ◽  
Fiber Reinforced Concrete ◽  
Mineral Admixtures ◽  
Test Results ◽  
River Sand ◽  
Split Tensile Strength ◽  
Manufactured Sand ◽  
Granulated Blast Furnace Slag ◽  
Strength Tests ◽  
Lime Stone

The production of Ordinary Portland Cement (OPC) is increasing year by year world over. Further, the production of every tonne of OPC generates one tonne of green house gases, (CO2 ) which results in Global Warming. Usage of OPC is more in construction industry as it is a major ingredient in Concrete. As the usage of Concrete is increasing year by year, more and more is the OPC production and hence the environment is getting polluted; added to this undesirable scenario, the natural resources like lime stone used to manufacture cement and river sand are getting depleted year by year. In order to prevent the usage of large amounts of OPC in Concrete, mineral admixtures like Ground Granulated Blast furnace Slag (GGBS), Fly Ash and Metakaolin which are pozzolanic and cementitious in nature are adopted to replace certain percentages of OPC. Manufactured Sand (M-sand) is adopted to replace river sand. Experimental investigation is conducted on fiber reinforced concrete with steel fibers @1% of weight of binder by casting requisite number of cubes and cylinders of concrete of grade M25; in these mixes OPC is replaced with GGBS, Fly Ash and Metakaolin up to 45%. Mechanical properties are determined by conducting compressive strength and split tensile strength tests; additionally some of the durability properties are established by conducting Water absorption and Sorptivity tests. Test results are comparable between controlled concrete and innovative concrete of present investigation.

Sign in / Sign up

Export Citation Format

Share Document