scholarly journals The Effect of Alkaline Activator Ratio on the Compressive Strength of Fly Ash-Based Geopolymer Paste

2017 ◽  
Vol 209 ◽  
pp. 012064 ◽  
Author(s):  
A V Lăzărescu ◽  
H Szilagyi ◽  
C Baeră ◽  
A Ioani
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Alkaline Activator ◽  
Geopolymer Paste

Effect of Mixing Procedure and Chemical Composition on Physical and Mechanical Performance of Geopolymers

2021 ◽  
Vol 1017 ◽  
pp. 41-50
Author(s):  
Natalia I. Kozhukhova ◽  
Anastasia Yu. Teslya ◽  
Natalia I. Alfimova ◽  
Marina I. Kozhukhova
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Ambient Temperature ◽  
Alkaline Solution ◽  
Component Composition ◽  
Temperature Treatment ◽  
Curing Temperature ◽  
Temperature Conditions ◽  
Alkaline Activator ◽  
Geopolymer Paste

Nowadays geopolymer is promising and relevant material that can be effectively used in wide range of application areas. It is possible because of there are a lot of potential sources of raw materials for geopolymer synthesis. Raw components are the one of the key parameters that effect on geopolymer performance. On the other hands, the technological stages of geopolymer synthesis is no less important factor. The purpose of this study was to determine effect of technological parameters of geopolymer synthesis such as component composition of solid state phase, alkaline activator preparation and its introduction onto geopolymer paste as well as curing temperature on performance characteristics of geopolymer. Fly-ash based geopolymer samples were prepared with adding of different mineral components: Portland cement (PC), kaolin, metakaolin; different curing temperature conditions: ambient temperature and temperature treatment at 70 °C in oven during 24 hours; different methods of preparation and application of alkaline activator: using of fresh alkaline solution and using alkaline solution after 24 hours of cooling. The results show that efficiency of curing temperature conditions strongly depend on component composition of geopolymer paste. Samples, containing PC and metakaolin demonstrate better characteristics after curing under ambient temperature. Samples, containing kaolin and reference composition (fly ash only) the temperature treatment in oven is the best curing method (increasing in compressive strength up to 13 times). Using alkaline solution of NaOH after 24 hours of cooling gives a good effect on geopolymerization process and provides increasing in compressive strength value from 13 to 84 % for all experimental geopolymer pastes. However, average density for all compositions is varied slightly.

The Effect of Dry Mix Sodium Hydroxide onto Workability and Compressive Strength of Geopolymer Paste

2020 ◽  
Vol 12 (9) ◽  
Author(s):  
A. Z. Mohd Ali ◽  
◽  
N. A. Jalaluddin ◽  
N. Zulkiflee ◽  
◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Alkaline Solution ◽  
High Emission ◽  
New Material ◽  
Curing Regime ◽  
Solid Form ◽  
Geopolymer Paste

The production of ordinary Portland cement (OPC) consumes considerable amount of natural resources, energy and at the same time contribute in high emission of CO2 to the atmosphere. A new material replacing cement as binder called geopolymer is alkali-activated concrete which are made from fly ash, sodium silicate and sodium hydroxide (NaOH). The alkaline solution mixed with fly ash producing alternative binder to OPC binder in concrete named geopolymer paste. In the process, NaOH was fully dissolved in water and cooled to room temperature. This study aims to eliminate this process by using NaOH in solid form together with fly ash before sodium silicate liquid and water poured into the mixture. The amount of NaOH solids were based on 10M concentration. The workability test is in accordance to ASTM C230. Fifty cubic mm of the geopolymer paste were prepared which consists of fly ash to alkaline solution ratio of 1: 0.5 and the curing regime of 80℃ for 24 hours with 100% humidity were implemented. From laboratory test, the workability of dry method geopolymer paste were decreased. The compressive strength of the dry mix of NaOH showed 55% and the workability has dropped to 58.4%, it showed strength reduction compared to the wet mix method.

scholarly journals Alkali-activated concretes based on fly ash and blast furnace slag: Compressive strength, water absorption and chloride permeability

2020 ◽  
Vol 40 (2) ◽  
Author(s):  
Daniela Eugenia Angulo-Ramírez ◽  
William Gustavo Valencia-Saavedra ◽  
Ruby Mejía de Gutiérrez
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Fly Ash ◽  
Water Absorption ◽  
Blast Furnace Slag ◽  
Construction Materials ◽  
Chloride Ion ◽  
Chloride Permeability ◽  
Alkaline Activator ◽  
Furnace Slag

Concretes based on alkaliactivated binders have attracted considerable attention as new alternative construction materials, which can substitute Portland Cement (OPC) in several applications. These binders are obtained through the chemical reaction between an alkaline activator and reactive aluminosilicate materials, also named precursors. Commonly used precursors are fly ash (FA), blast furnace slag (GBFS), and metakaolin. The present study evaluated properties such as compressive strength, rate of water absorption (sorptivity), and chloride permeability in two types of alkaliactivated concretes (AAC): FA/GBFS 80/20 and GBFS/OPC 80/20. OPC and GBFS/OPC* concretes without alkaliactivation were used as reference materials. The highest compressive strength was observed in the FA/GBFS concrete, which reported 26,1% greater strength compared to OPC concrete after 28 days of curing. The compressive strength of alkaliactivated FA/GBFS 80/20 and GBFS/OPC 80/20 was 61 MPa and 42 MPa at 360 days of curing, respectively. These AAC showed low permeability to the chloride ion and a reduced water absorption. It is concluded that these materials have suitable properties for various applications in the construction sector.

Effect of Curing Time and Sintering to the Properties of Geopolymer Mortars

2017 ◽  
Vol 888 ◽  
pp. 184-187
Author(s):  
Salwa Ismail ◽  
Mohammad Faizal Mohd Razali ◽  
Izwan Johari ◽  
Zainal Arifin Ahmad ◽  
Shah Rizal Kasim
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Distilled Water ◽  
Curing Time ◽  
Pore Former ◽  
X Ray ◽  
Before And After ◽  
Naoh Solution ◽  
Added Water ◽  
Alkaline Activator

In this study, the geopolymer mortars were synthesized with fly ash (FA) and silica powder as aluminosilicate sources and a combination of sodium hydroxide (NaOH) solution, sodium silicate (Na2SiO3) solution and distilled water as alkaline activator. Commercial sago was used as a pore former in the mortars. The percentage of sago used were 10, 20 and 30 wt% of FA. The amount of added water used in each mixture was 5% by weight of FA, NaOH solution and Na2SiO3 solution. The formed geopolymer mortars were cured for 1, 3 and 7 days and sintered at 1000 °C. X-ray fluoresence (XRF) shown that FA contains higher amount of silica (SiO2) and alumina (Al2O3) which is important as aluminosilicate sources. The properties of the geopolymer mortars before and after sintered at 1000 °C have been investigated. The results show that geopolymer mortars with 10% of sago content with curing time of 7 days and sintered at 1000 °C give the highest compressive strength of 13.5 MPa.

The Effect of Curing Time on the Properties of Fly Ash-Based Geopolymer Bricks

2012 ◽  
Vol 626 ◽  
pp. 937-941 ◽  
Author(s):  
W.I. Wan Mastura ◽  
H. Kamarudin ◽  
I. Khairul Nizar ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
H. Mohammed
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Water Absorption ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Experimental Work ◽  
Base Material ◽  
Curing Time ◽  
Curing Conditions ◽  
Alkaline Activator

This paper reports the results of an experimental work conducted to investigate the effect of curing conditions on the properties of fly ash-based geopolymer bricks prepared by using fly ash as base material and combination of sodium hydroxide and sodium silicate as alkaline activator. The experiments were conducted by varying the curing time in the range of 1-24 hours respectively. The specimens cured for a period of 24 hours have presented the highest compressive strength for all ratio of fly ash to sand. For increasing curing time improve compressive strength and decreasing water absorption.

scholarly journals Compressive strength of medium calcium fly ash based geopolymer paste

2020 ◽  
Vol 419 ◽  
pp. 012027
Author(s):  
I N Guntur ◽  
M W Tjaronge ◽  
R Irmawaty ◽  
J J Ekaputri
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Geopolymer Paste

COMPRESSIVE STRENGTH OF GEOPOLYMER MORTAR USING GROUND FERRONICKEL SLAG AND FLY ASH

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Jhutan Chandra Kuri ◽  
Md Nabi Newaz Khan ◽  
Prabir Kumar Sarker
Keyword(s):  
Stainless Steel ◽  
Compressive Strength ◽  
Fly Ash ◽  
Nickel Alloy ◽  
Strength Increase ◽  
Reaction Products ◽  
Huge Amount ◽  
Alkaline Activator ◽  
Ferronickel Slag

A huge amount of ferronickel slag is produced as a by-product of manufacturing ferronickel, which is used in stainless steel and nickel alloy. This paper presents the effect of using different percentages of ground ferronickel slag (GFNS) with fly ash (FA) on the workability and compressive strength of geopolymer mortar. A mixture of NaOH and Na2SiO3 solutions was used as the alkaline activator. It was found that the flow of fresh mortar decreased with the increase of GFNS content. This is attributed to the higher fineness and angular shape of GFNS particles as compared to spherical fly ash particles. The mortar cube specimens were heat-cured at 60 °C for 24 hours. The compressive strength of geopolymer mortar using 100% FA was 54 MPa and it increased by 17%, 21% and 36% for using 25%, 50% and 75% GFNS as fly ash replacement, respectively. The strength increase is attributed to the increase of Si/Al ratio by GFNS that favoured the production of alkali aluminosilicate reaction products.

Nano Geopolymer for Sustainable Concrete Using Fly Ash Synthesized by High Energy Ball Milling

2013 ◽  
Vol 313-314 ◽  
pp. 169-173 ◽  
Author(s):  
A.M. Mustafa Al Bakri ◽  
H. Kamarudin ◽  
M. Bnhussain ◽  
J. Liyana ◽  
Che Mohd Ruzaidi Ghazali
Keyword(s):  
Fly Ash ◽  
Ball Milling ◽  
Total Duration ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Sustainable Concrete ◽  
Entire Experiment ◽  
Energy Ball ◽  
Alkaline Activator ◽  
Geopolymer Paste

This paper presents the development of a nano geopolymer for sustainable concrete using fly ash synthesized by high-energy ball milling. In this paper, we report on our investigation of the effects of grinding on the binder properties and the optimization of the mix design for nano geopolymer paste. The research methodology consisted of synthesizing fly ash by using a high-energy ball mill to create nanosized particles and determining the formulation and mix proportions required to produce a nano geopolymer paste with the addition of an alkaline activator. The ratio of fly ash to alkaline activator and sodium silicate to sodium hydroxide were constant for the entire experiment which is 2.5. Ball milling was conducted for the total duration of six hours, during which particle size was reduced from 10 μm to 60 nm. The nano geopolymer were cured at temperature 70°C and then tested on 1st day and 7th day for compressive strength. Scanning electron microscopy (SEM) was used to characterize the shape, texture, and size of the milled fly ash.

Sign in / Sign up

Export Citation Format

Share Document