A Study on Relationship between Porosity and Compressive Strength for Geopolymer Paste

2013 ◽  
Vol 594-595 ◽  
pp. 1112-1116 ◽  
Author(s):  
Z.F. Farhana ◽  
H. Kamarudin ◽  
Azmi Rahmat ◽  
A.M. Mustafa Al Bakri
Keyword(s):  
Compressive Strength ◽  
Sodium Hydroxide Solution ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Pulse Velocity ◽  
Strength Test ◽  
Compressive Strength Test ◽  
Alkaline Activator ◽  
The Relationship ◽  
Geopolymer Paste

This paper presents a study on the relationship between porosity and compressive strength for geopolymer paste. In this research, geopolymer paste was made from fly ash class F based geopolymer mixed with alkaline activator; sodium hydroxide solution and sodium silicate solution. Twelve mixes were cast in 50mm x 50mm x 50mm moulds and the samples were cured for 24 hrs at 60 °C in the oven. The samples were examined after 7, 14, 28 and 90 days in terms of porosity test, pulse velocity test and compressive strength test. It was concluded that the sample at day 90 had the highest compressive strength of 56.50 N/mm2had porosity 3.77%. Thus, the sample with lowest porosity had highest pulse velocity 3303 m/s during ultrasonic testing with lowest transmission time 15.17 μs. Keywords: porosity, compression strength, geopolymer, pulse velocity

Effects of Alkaline Solution on the Properties of Slag Based Geopolymer

2018 ◽  
Vol 877 ◽  
pp. 193-199 ◽  
Author(s):  
Suman Saha ◽  
C. Rajasekaran
Keyword(s):  
Compressive Strength ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Alkaline Solution ◽  
Sodium Hydroxide Solution ◽  
Setting Time ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Hydroxide Solution ◽  
Geopolymer Paste

Production of Ordinary Portland Cement (OPC) requires huge quantity of natural resources and energy and it releases large amount of carbon - di - oxide to the environment. Therefore, enormous studies have been carried out throughout the world to establish geopolymer as an alternative binder material for the replacement of OPC to protect the environment. This study intends to explore the effects of alkaline solution on the properties of geopolymer produced with ground granulated blast furnace slag. Properties such as Standard consistency, setting time of slag based geopolymer paste has been determined using Vicat’s apparatus (according to the guidelines given by Indian Standards for OPC). In order to determine the effects of alkaline solution on the properties of geopolymers, the concentration of sodium hydroxide solution has been varied from 6M to 16M and the ratio of sodium silicate solution to sodium hydroxide solution is also varied from 1.0 to 2.0. Results indicate higher standard consistency and significant less setting time for slag based geopolymer paste than that of OPC paste. Compressive strength of the geopolymer paste and mortar cube samples, cured in ambient conditions till the day of testing, is increasing with the increase of the concentration of sodium hydroxide solution. Highest compressive strength is obtained for the samples prepared with alkaline solution having the ratio of sodium silicate solution to sodium hydroxide solution as 1.5. But when the concentration of sodium hydroxide solution is beyond 14M, decreasing trend in compressive strength is observed.

Effect of Partial Replacement of Fly Ash by Metakaolin on Strength Development of Fly Ash Based Geopolymer Mortar

2017 ◽  
Vol 744 ◽  
pp. 131-135 ◽  
Author(s):  
Muhammad Zahid ◽  
Nasir Shafiq ◽  
Mohd Fadhil Nuruddin ◽  
Ehsan Nikbakht ◽  
Asif Jalal
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Hydroxide Solution ◽  
Base Material ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Partial Replacement ◽  
Strength Development ◽  
Class C ◽  
Class F

This article aims to investigate the compressive strength variation by the addition of metakaolin as a substitute of fly ash in the fly ash based geopolymer mortar. Five, ten and fifteen percent by weight of fly ash was replaced by highly reactive metakaolin. Two type of fly ashes namely, ASTM class F and ASTM class C were used as a base material for the synthesis of geopolymer mortar. Eight molar sodium hydroxide solution mixed with sodium silicate solution was used as alkaline activator. For optimum geopolymerization, mortar was cured at sixty degree Celsius for twenty four hours duration. Results show different behavior of metakaolin replacement on compressive strength for two different types of fly ash based geopolymer mortar. Improvement in compressive strength was seen by addition of metakaolin in ASTM class F fly ash based geopolymer. On the other hand compressive strength was decreased abruptly in fly ash class C based geopolymer up to certain replacement level.

Effect of Adding Sago and Sintering to the Properties of Geopolymer Mortar

2020 ◽  
Vol 1010 ◽  
pp. 659-664
Author(s):  
Mohamad Abdul Zahari Aziz ◽  
M.M.R. Faizal ◽  
Izwan Johari ◽  
Shah Rizal Kasim
Keyword(s):  
Compressive Strength ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Content Increase ◽  
Curing Time ◽  
Sintering Process ◽  
Silicate Mineral ◽  
Pore Former ◽  
X Ray ◽  
Alkaline Activator

Geopolymer is an alternative cementitious material produced by rich Alumino Silicate mineral materials (Si-Al) combine with alkaline activator. The objectives in this study are to introduce pores by using sago as pore former and to determine the effect of curing time and sintering process to geopolymer mortar properties. There are three compositions of mortar used in this study with different sago content (10%, 20%, and 30%) and each composition of mortar have different curing time (1, 3 and 7 days). Fly ash, silica powder, alkaline activator (sodium silicate solution (Na2SiO3) and sodium hydroxide (NaOH) and sago were mixed together based on their composition and the mixture were put into steel cubic mould (50 mm x 50 mm x 50 mm) and left at room temperature for curing process. After the mortar reaches their curing time, it will be sintered at 1000 °C. The physical changes of the mortar were analysed before and after the sintering process. The microstructure of mortar was observed using Scanning Electron Microscope (SEM). Compression test was done to geopolymer mortars by using ADR-Auto 3000 from ELE instrument (ASTM C109 standard) to determine the mechanical properties. Fourier-transform infrared (FTIR) analysis used to determine the functional group exist in geopolymer mortar and X-ray Diffraction (XRD) was used to determine the phase. Besides that, Energy dispersive X-ray spectroscopy (EDX) use to measure percentage elements exist in a mortar. Geopolymer mortar with 10% sago content, 7 days of curing and undergo sintering process have the highest compressive strength (13.46 N) compare to the other geopolymer mortar composition. The 30% sago mortar contain many pores after sintering contributes its brittleness and cannot be tested for compressive strength. Longer curing days give enough time for the geopolymerisation process to create strong Si-O-Al bond or Jadeite (N-A-S-H gels) while sintering process helps to speed up the geopolymerisation process take place in a mortar. Formation of jadeite (N-A-S-H gels) influenced the strength of the mortar. The increasing phase of jadeite increases the strength of the mortar. As sago content increase, the pores in geopolymer also increase but the ratio Al2O3:SiO2 decrease resulting low formation of Jadeite. Hence the compressive strength of geopolymer mortar decrease.

scholarly journals Effect of Concentration of Sodium Hydroxide and Degree of Heat Curing on Fly Ash-Based Geopolymer Mortar

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Subhash V. Patankar ◽  
Yuwaraj M. Ghugal ◽  
Sanjay S. Jamkar
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Sodium Hydroxide Solution ◽  
Large Change ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Test Period ◽  
Hydroxide Solution ◽  
Increase With Increase

Geopolymer concrete/mortar is the new development in the field of building constructions in which cement is totally replaced by pozzolanic material like fly ash and activated by alkaline solution. This paper presented the effect of concentration of sodium hydroxide, temperature, and duration of oven heating on compressive strength of fly ash-based geopolymer mortar. Sodium silicate solution containing Na2O of 16.45%, SiO2 of 34.35%, and H2O of 49.20% and sodium hydroxide solution of 2.91, 5.60, 8.10, 11.01, 13.11, and 15.08. Moles concentrations were used as alkaline activators. Geopolymer mortar mixes were prepared by considering solution-to-fly ash ratio of 0.35, 0.40, and 0.45. The temperature of oven curing was maintained at 40, 60, 90, and 120°C each for a heating period of 24 hours and tested for compressive strength at the age of 3 days as test period after specified degree of heating. Test results show that the workability and compressive strength both increase with increase in concentration of sodium hydroxide solution for all solution-to-fly ash ratios. Degree of heating also plays vital role in accelerating the strength; however there is no large change in compressive strength beyond test period of three days after specified period of oven heating.

scholarly journals Kelayakan Abu Terbang PLTU Buntoi Sebagai Campuran Beton Geopolimer

2021 ◽  
Vol 9 (2) ◽  
pp. 102-108
Author(s):  
Dadang Suriyana ◽  
Liliana Sahay ◽  
Okta Meilawaty
Keyword(s):  
Compressive Strength ◽  
Strength Test ◽  
Geopolymer Concrete ◽  
Conventional Concrete ◽  
Second Stage ◽  
Compressive Strength Test ◽  
Compressive Strength Of Concrete ◽  
Maximum Compressive Strength ◽  
Geopolymer Material ◽  
Geopolymer Paste

The main basic ingredients needed for the manufacture of this geopolymer material are materials that contain a lot of silica and aluminia elements. The 1st stage test was carried out to determine the geopolymer paste with the maximum compressive strength at the ratio of NaOH to Na2SiO3 of 1; 1.5; 2; 2.5. The second stage of testing was carried out using a geopolymer paste with the highest compressive strength, namely the ratio of NaOH to Na2SiO3 of 2.5 with a compressive strength of 22.56 MPa. Based on the results of the compressive strength test, the maximum compressive strength at the age of 28 days is 7.64 MPa. The results of the compressive strength of concrete are much lower than the compressive strength of the paste, it shows that the paste does not bind too much with the aggregate. This is evidenced by the results of the compressive strength of conventional concrete which is much higher than that of geopolymer concrete using the same aggregate. With the results of the maximum compressive strength at the age of 28 days is 29.51 MPa.

Consolidation of Sand by Alkaline Silicate Solution

2010 ◽  
Vol 68 ◽  
pp. 84-89
Author(s):  
Sandrine Lucas ◽  
Monique Tohoué Tognonvi ◽  
Julien Soro ◽  
Sylvie Rossignol ◽  
Jean Louis Gelet
Keyword(s):  
Electron Microscopy ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Strength Test ◽  
Gravimetric Analysis ◽  
Compressive Strength Test ◽  
Concentration Of Solutions ◽  
Sand Particles ◽  
Increasing Temperature ◽  
Scanning Electron

Progress of fuse technology to reduce cost and to protect environment requires the understanding of physicochemical phenomena that govern the consolidation of the sand with alkaline silicate solution. In this context, this work concerns the agglomeration behaviours of sand with alkaline silicate solution. The effects of sand particles size and concentration of solutions are investigated at various temperatures. The main objective is to understand the interactions between sand and this alkaline solution during the impregnation of sand with sodium silicate solution and the drying leading to the consolidated materials. Various investigations were performed, thermogravimetrical and differential thermal analysis (TG/DTA), gravimetric analysis of wet sample, scanning electron microscopy (SEM) and compressive strength test on dry samples. The results show that agglomeration is affected by silica grains size distribution and temperature. Bonds strength between the grains increase with decreasing grain size and increasing temperature.

scholarly journals The effect of curing on compressive strength of geo-polymer mortar made rice straw ash, fly ash, and laterite soil

2021 ◽  
Vol 921 (1) ◽  
pp. 012009
Author(s):  
P R Rangan ◽  
R Irmawaty ◽  
M W Tjaronge ◽  
A A Amiruddin ◽  
B Bakri ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Strength Test ◽  
Laterite Soil ◽  
Compressive Strength Test ◽  
Polymer Mortar ◽  
Alkaline Activator ◽  
Water Curing ◽  
Straw Ash ◽  
Percentage Ratio

Abstract This study aims to analyze the effect of curing on the compressive strength of geopolymer mortar made from straw ash, fly ash and laterite soil. This research is experimental in the laboratory. Geopolymer mortar was produced using straw ash, fly ash and laterite soil with a percentage ratio of 16.67: 41.67: 41.67. The alkaline activator used is sodium hydroxide (NaOH) with a concentration of 12 M. The compressive strength test of 5 × 10 cm cylinders is used to evaluate the geopolymer mortar mixture produced at the age of 3, 7 and 28 days with curing, namely air and water curing. The results showed that the compressive strength of the geopolymer mortar increased along with the increasing age of each curing. The compressive strength values produced in air curing 3, 7 and 28 days were respectively 1.64 N/mm2, 1.72 N/mm2 and 3.22 N/mm2. While water curing, the resulting compressive strength values for each curing are 1.03 N/mm2, 1.63 N/mm2 and 1.68 N/mm2. At the ages of 3, 7 and 28 days, there was an increase in the compressive strength values from water curing to air curing, which were 0.37%, 5.23% and 47.82%, respectively. It can be seen that the compressive strength of the geopolymer mortar made from straw ash, fly ash and laterite soil in air curing is greater than that of water curing.

Fabrication and Characterization of Geopolymers from Japanese Volcanic Ashes

2014 ◽  
Vol 92 ◽  
pp. 1-7
Author(s):  
Shinobu Hashimoto ◽  
Hayami Takeda ◽  
Tatsuya Machino ◽  
Haruka Kanie ◽  
Sawao Honda ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Volcanic Ash ◽  
Sodium Hydroxide Solution ◽  
Water Immersion ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Hydroxide Solution ◽  
Volcanic Ashes

Geopolymers were fabricated from some Japanese volcanic ashes. 30 g of volcanic ash with 200μm in diameter was mixed with 10 ml of sodium hydroxide solution with various concentrations to form slurry which became geopolymer after curing. When 8.5~11.5 mol/L of sodium hydroxide solution was used, the compressive strength of the resultant geopolymers reached to 25-35MPa. However, when the volcanic ash with high silica content was used, the compressive strength of the geopolymer was under 20 MPa. Furthermore, the addition of sodium silicate hydrate into starting slurry which was consisted of volcanic ash and sodium silicate solution had not effected on the compressive strength of geopolymer. In contrast, the compressive strength of the geopolymer decreased to 30 % of compressive strength compared to that of original geopolymer after water immersion for 3 days. However, crushing treatment of the volcanic ash contributed to retain the compressive strength. Actually, when 10μm of volcanic ash was used to fabricate geopolymer, the compressive strength improved to 70% compared to that of original geopolymer.

Effect of Bentonite Addition on Geopolymer Concrete from Geothermal Silica

2016 ◽  
Vol 841 ◽  
pp. 7-15 ◽  
Author(s):  
Himawan Tri Bayu Murti Petrus ◽  
Joshepine Hulu ◽  
Gede S.P. Dalton ◽  
Elsa Malinda ◽  
Rizal Agung Prakosa
Keyword(s):  
Compressive Strength ◽  
Room Temperature ◽  
Sem Analysis ◽  
Strength Test ◽  
Raw Material ◽  
Curing Temperature ◽  
Curing Time ◽  
Compressive Strength Test ◽  
Temperature Optimization ◽  
Alkaline Activator

Silica scaling is one of major problems in geothermal power plant. Silica recovery is a promising method to solve this particular problem in regard to silica utilization as geopolimer concrete. In this experimental study, bentonite was used as raw alumina source. Experiments were conducted by means observing the geopolymerization through alkaline activator ratio, raw material ratio, and temperature optimization. After mixing and casting for 24 hours, samples were cured at 80°C, 100°C, and 120°C for certain period of time and kept at room temperature for 7 days before compressive strength test. The optimum curing time and temperature gained from this experiment were 120 minutes and 100°C with compressive strength of 29.16 MPa. The development of geopolymer bond and microstructure of samples were then investigated by SEM technique. Scanning electron microscopy (SEM) analysis also showed better improvement in geopolymer layer of concrete sample with increasing curing temperature.

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