scholarly journals Studi Mikrostruktur Mortar Geopolimer Abu Sawit dengan Variasi Rasio Na2SiO3 terhadap NaOH

2019 ◽  
Vol 19 (1) ◽  
pp. 132
Author(s):  
Wari Dony ◽  
Amsori M Das
Keyword(s):  
Compressive Strength ◽  
Oil Palm ◽  
Building Materials ◽  
Construction Material ◽  
Geopolymer Concrete ◽  
Alkali Activator ◽  
Industry Waste ◽  
Result Show ◽  
Naoh Solution ◽  
Oil Palm Ash

In the context development of building materials geopolymer concrete is an environmentally technology. The goal of the study identifies and examines geopolymer concrete becoming  alternative to portland cement (PC) as a construction material section is utilized as one of the local plantation industry waste such as oil palm ash. Polymerzation process performed the oil palm ash as precursor that contains high silicate calcium with Na2SiO3 and NaOH as alkali activator. Mix design is carried out by ratio of alkali activator 2,0. 1,5 and  1,0  at a concentration of NaOH 8, 10, 12, 14 and 16 M at temperature 90°C for 24 hours. The method used is the separate mixtures with extra water and mixed methods directly without extra water. The result show that the higher concentration of NaOH solution, the compressive strength is increased at level of 12,4 Mpa=8,4 M for the mortar with extra water and 20,2 Mpa= 16 M without extra water at ratio of 1,5 alkaline activators. The ratio mixture of alkali activator 1,0and 2,0 would produce a low compressive strength. Microstructure result shows that matrix is formed more solid at each increase in the concentration of Na OH solution. The ratio of Alkali activator 1,5 causing precursors and alkaline activators to react homogeneously so that the formed geopolymer matrix becomes more solid

scholarly journals Resistance to Sulfuric Acid Corrosion of Geopolymer Concrete Based on Different Binding Materials and Alkali Concentrations

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7109
Author(s):  
Wei Yang ◽  
Pinghua Zhu ◽  
Hui Liu ◽  
Xinjie Wang ◽  
Wei Ge ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
Fly Ash ◽  
Acid Corrosion ◽  
Geopolymer Concrete ◽  
High Calcium ◽  
High Calcium Fly Ash ◽  
Naoh Solution ◽  
Sulfuric Acid Corrosion

Geopolymer binder is expected to be an optimum alternative to Portland cement due to its excellent engineering properties of high strength, acid corrosion resistance, low permeability, good chemical resistance, and excellent fire resistance. To study the sulfuric acid corrosion resistance of geopolymer concrete (GPC) with different binding materials and concentrations of sodium hydroxide solution (NaOH), metakaolin, high-calcium fly ash, and low-calcium fly ash were chosen as binding materials of GPC for the geopolymerization process. A mixture of sodium silicate solution (Na2SiO3) and NaOH solution with different concentrations (8 M and 12 M) was selected as the alkaline activator with a ratio (Na2SiO3/NaOH) of 1.5. GPC specimens were immersed in the sulfuric acid solution with the pH value of 1 for 6 days and then naturally dried for 1 day until 98 days. The macroscopic properties of GPC were characterized by visual appearance, compressive strength, mass loss, and neutralization depth. The materials were characterized by SEM, XRD, and FTIR. The results indicated that at the immersion time of 28 d, the compressive strength of two types of fly ash-based GPC increased to some extent due to the presence of gypsum, but this phenomenon was not observed in metakaolin-based GPC. After 98 d of immersion, the residual strength of fly ash based GPC was still higher, which reached more than 25 MPa, while the metakaolin-based GPC failed. Furthermore, due to the rigid 3D networks of aluminosilicate in fly ash-based GPC, the mass of all GPC decreased slightly during the immersion period, and then tended to be stable in the later period. On the contrary, in metakaolin-based GPC, the incomplete geopolymerization led to the compressive strength being too low to meet the application of practical engineering. In addition, the compressive strength of GPC activated by 12 M NaOH was higher than the GPC activated by 8 M NaOH, which is owing to the formation of gel depended on the concentration of alkali OH ion, low NaOH concentration weakened chemical reaction, and reduced compressive strength. Additionally, according to the testing results of neutralization depth, the neutralization depth of high-calcium fly ash-based GPC activated by 12 M NaOH suffered acid attack for 98 d was only 6.9 mm, which is the minimum value. Therefore, the best performance was observed in GPC prepared with high-calcium fly ash and 12 M NaOH solution, which is attributed to gypsum crystals that block the pores of the specimen and improve the microstructure of GPC, inhibiting further corrosion of sulfuric acid.

Developing Environmentally Sustainable and Cost-Effective Geopolymer Concrete with Improved Characteristics

2021 ◽  
Vol 13 (24) ◽  
pp. 13607
Author(s):  
Alexey N. Beskopylny ◽  
Sergey A. Stel’makh ◽  
Evgenii M. Shcherban’ ◽  
Levon R. Mailyan ◽  
Besarion Meskhi ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Building Materials ◽  
Cost Effective ◽  
Point Of View ◽  
Strength Characteristics ◽  
Geopolymer Concrete ◽  
Environmental Friendliness ◽  
Fine Grained ◽  
The Individual ◽  
Capital Construction

Improving the efficiency and quality of construction mainly depends on the cost of building materials, which is about 55–65% of total capital-construction costs. The study aimed to obtain geopolymer fine-grained concrete with improved quality characteristics that meet the construction field’s sustainable development criteria and that have environmental friendliness, economic efficiency, and advantages over competing analogues. The dependences of strength characteristics on various compositions of geopolymer concrete were obtained. It was found that the most effective activator is a composition of NaOH and Na2SiO3 with a ratio of 1:2. The increase in the indicators of the obtained geopolymer concrete from the developed composition (4A) in relation to the base control (1X) was 17% in terms of compressive strength and 24% in tensile strength in bending. Polynomial equations were obtained showing the dependence of the change in the strength characteristics of geopolymer concrete on the individual influence of each of the activators. A significant effect of the composition of the alkaline activator on the strength characteristics of geopolymer fine-grained concrete was noted. The optimal temperature range of heat treatment of geopolymer concrete samples, contributing to the positive kinetics of compressive strength gain at the age of 28 days, was determined. The main technological and recipe parameters for obtaining geopolymers with the desired properties, which meet the ecology requirements and are efficient from the point of view of economics, were determined.

THE EFFECT OF OIL PALM ASH INCORPORATION IN FOAMED CONCRETE

2015 ◽  
Vol 75 (5) ◽  
Author(s):  
Farah A. Hadi ◽  
Hanizam Awang ◽  
Muhammed Zuhear Almulali
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Oil Palm ◽  
Drying Shrinkage ◽  
Target Density ◽  
Concrete Mix ◽  
Different Ages ◽  
Foamed Concrete ◽  
Oil Palm Ash ◽  
Enhanced Properties

This paper investigates the effect of replacing different portions of cement by fine oil palm ash (FOPA). A target density of 1000 kg/m3 was used for the foamed concrete mixes. A foamed concrete mix of 1 part binder, 2 parts filler and 0.45 part of water has been used. Cement was replaced at levels of 25, 35, 45, 55 and 65% by weight of binder. The compressive strength, density, water absorption, drying shrinkage and sorptivity were tested at different ages. The mix containing 25% of fine OPA showed enhanced properties in comparison to the control mix at the age of 90 days. The mixed showed higher compressive strength, less water absorption, increased density and lesser sorptivity. However, the same mix showed higher shrinkage readings than that of the control mix. 

scholarly journals Effect of Ordinary Portland Cement on Some Properties of Pervious Geopolymer Concrete

2021 ◽  
Vol 39 (4A) ◽  
pp. 668-674
Author(s):  
Wasan I. Khalіl ◽  
Qaіs J. Frayyeh ◽  
Haider Abed
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Total Content ◽  
Dry Density ◽  
Geopolymer Concrete ◽  
Naoh Solution

In this research, a study is made on the Pervious Geopolymer Concrete (PGC), which is based on localmaterial(Metakaolin). The inclusion of Ordinary Portland Cement (OPC) as a partial substitute for Metakaolin (MK) for the production of (PGCs) has also been investigated. Pervious Geopolymer concrete was outputted from the local Metakaolin (MK), and ordinary Portland cement (OPC) as a partial substitute by weight of MK and silicate of sodium (Na2SiO3) and hydroxide of sodium (NaOH) solution. All PGC samples were cured after 24 hours from casting for five hours at a degree of the temperature of 50 ° C, then the testingafter 28 days. The compressive-strength, total content of voids, the strength of bending, dry-density, and thermal-conductivity of pervious Geopolymer concrete were examined. The mechanicalresults of testing ranged from (11.03 and 2.25) to (14.3 and 2.75) MPa for compressive-strength and flexural strength respectively.

scholarly journals Compressive Strength of Fly Ash Based Geopolymer Concrete Addition with Fibers

2020 ◽  
pp. 57-61
Author(s):  
B Anitha Rani V Bhargavi,
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Construction Material ◽  
Polypropylene Fibers ◽  
Geopolymer Concrete ◽  
Inorganic Polymers ◽  
Cement Production ◽  
Compressive Strength Test ◽  
New Generation ◽  
Day By Day

Concrete is the most widely used construction material all over the world. The quantity of the water plays an important role in the preparation of concrete. And the demand of concrete is increasing day by day and cement is used for satisfying the need of development of infrastructure facilities, 1 tonne cement production generates 1 tonne CO2, which adversely affect the environment. In order to reduce the use of OPC and CO2 generation, the new generation concrete has been developed such as Geopolymer concrete (GPC). Geopolymers are inorganic polymers and their chemical composition is similar to natural materials. Geopolymer binders are the alternatives in the development of acid resistant concrete i.e. durability of concrete. Geopolymer concrete is produced using Fly ash at 100% replacement to cement and binders like NaOH, Na2SiO3 to ignite the geopolymerisation. Many studies were carried out on properties of geopolymer concrete. This study focuses on enhancing the strength of geopolymer concrete by using fibers. 60% polyester and 40% polypropylene fibers are added to geopolymer concrete addition with Fly ash content. The trail mixes were casted with addition of fibers at different percentages like (0.20, 0.25, 0.30, 0.35, 0.40, 0.45 and 0.50 %). Then samples were air-cured for 28 days at ambient temperature. Compressive strength test is conducted on the samples after 3, 7 and 28 days. The optimum value is obtained at 0.40% addition of fibers when compared to nominal mix(GPC).

An Ultrasonic Pulse Velocity Test on Fly-Ash Based Geopolymer Concrete in Frequency Domains

2014 ◽  
Vol 700 ◽  
pp. 310-313 ◽  
Author(s):  
Jee Sang Kim ◽  
Tae Hong Kim
Keyword(s):  
Compressive Strength ◽  
Construction Material ◽  
High Strength ◽  
Ultrasonic Pulse Velocity ◽  
Peak Frequency ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
P Wave ◽  
Geopolymer Concrete ◽  
Existing Structures

The Non-Destructive Test techniques on concrete, which can assess the properties of materials without damages, have been developed as the deteriorations of existing structures increase. Among them, the ultrasonic pulse velocity (USPV) method is widely used because it can investigate the states of one material for a long time and repeatedly. However, there have been few researches on the NDT application to geopolymer concrete which is environment friendly construction material without any cement. This paper investigates the variations of ultrasonic pulse velocity and peak frequency of geopolymer concrete under monotonically increasing loads to assess the material conditions with various compressive strength levels by measuring P-wave signals. The pulse velocities and peak frequencies were higher in high strength geopolymer concrete specimens. There are not explicit relations between strength levels and peak frequencies but the peak frequencies are strongly influenced by the applied stress levels. In addition, a predicting equation for compressive strength of geopolymer concrete is derived based on experimental data in similar form for normal concrete.

scholarly journals Preparation and Characterization of Ultra-Fine Oil Palm Ash Powder by Ultrasonication and Alkaline Treatment for Its Evaluation as Reinforcing Filler in Natural Rubber

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 100
Author(s):  
Methakarn Jarnthong ◽  
Chutarat Malawet ◽  
Lusheng Liao ◽  
Puwang Li ◽  
Zheng Peng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Natural Rubber ◽  
Oil Palm ◽  
Average Particle Size ◽  
Alkaline Treatment ◽  
Bet Surface Area ◽  
Average Particle ◽  
Naoh Solution ◽  
Oil Palm Ash

Ultra-fine oil palm ash (OPA) particles were successfully prepared using ultrasonication along with optimal chemical deagglomeration. The influence of chemical treatment by sodium hydroxide (NaOH) solution on the OPA particles was found to be an important factor in enhancing deagglomeration efficiency. The average particle size of the original OPA (41.651 μm) decreased remarkably more than 130 times (0.318 μm) with an obvious increase of Brunauer–Emmet–Teller (BET) surface area after treating the OPA with 3M NaOH, followed by ultrasonication for 30 min. The changes in particle size and surface morphology were investigated using transmission electron microscopy and scanning electron microscopy. Moreover, the chemical functional groups of the untreated and treated OPA showed different patterns of infrared spectra by the presence of sodium carbonate species owing to the effect of NaOH treatment. The incorporation of both untreated and treated OPA in natural rubber by increasing their loading can improve cure characteristics (i.e., reducing optimum cure time and increasing torques) and cure kinetic parameters (i.e., increasing the rate of cure and reducing activation energy). Nevertheless, the strength, degree of reinforcement, and thermal stability of treated OPA as well as wettability between treated OPA particles and NR were greater than that resulting from the untreated OPA.

scholarly journals A Comprehensive Study on the Factors Affecting the Workability and Mechanical Properties of Ambient Cured Fly Ash and Slag Based Geopolymer Concrete

2021 ◽  
Vol 11 (18) ◽  
pp. 8722
Author(s):  
Rana Muhammad Waqas ◽  
Faheem Butt ◽  
Xulong Zhu ◽  
Tianshui Jiang ◽  
Rana Faisal Tufail
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Geopolymer Concrete ◽  
Factors Affecting ◽  
Naoh Solution ◽  
New Material ◽  
Comprehensive Study ◽  
Slag Content

Geopolymer concrete (GPC), also known as an earth friendly concrete, has been under continuous study due to its environmental benefits and potential as a sustainable alternative to conventional concrete construction. However, there is still a lack of comprehensive studies focusing on the influence of all the design mix variables on the fresh and strength properties of GPC. GPC is still a relatively new material in terms of field application and has yet to secure international acceptance as a construction material. Therefore, it is important that comprehensive studies be carried out to collect more reliable information to expand this relatively new material technology to field and site applications. This research work aims to provide a comprehensive study on the factors affecting the fresh and hardened properties of ambient cured fly ash and slag based geopolymer concrete (FS-GPC). Industrial by-products, fly ash from thermal power plants, and ground granulated blast furnace slag from steel industries were utilized to produce ambient cured FS-GPC. A series of experiments were conducted to study the effect of various parameters, i.e., slag content (10%, 20%, 30%, and 50%), amount of alkaline activator solution (AAS) (35% and 40%), sodium silicate (SS) to sodium hydroxide (SH) ratio (SS/SH = 2.0, 2.5 and 3.0), sodium hydroxide concentration (10 M, 12 M, and 14 M) and addition of extra water on fresh and mechanical properties of FS-GPC. The workability of the fresh FS-GPC mixes was measured by the slump cone test. The mechanical properties of the mixes were evaluated by compressive strength, split tensile strength, flexure strength, and static modulus tests. The results revealed that workability of FS-GPC is greatly reduced by increasing slag content, molarity of NaOH solution, and SS/SH ratio. The compressive strength was improved with an increase in the molarity of NaOH solution and slag content and a decrease in AAS content from 40% to 35%. However, the influence of SS/SH ratio on mechanical properties of FS-GPC has a varying effect. The addition of extra water to enhance the workability of GPC matrix caused a decrease in the compressive strength. The validity of the equations suggested by previous studies to estimate the tensile and flexural strength and elastic modulus of FS-GPC mixes were also evaluated. Based on the test results of this study, empirical equations are proposed to predict the splitting tensile strength, flexural strength, and elastic modulus of ambient cured FS-GPC. The optimal mixtures of FS-GPC in terms of workability and mechanical properties were also proposed for the field applications.

INFLUENCE OF CURING CONDITIONS AND ALKALI HYDROXIDE ON STRENGTH OF FLY ASH GEOPOLYMER CONCRETE

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Khoa Tan Nguyen ◽  
Tuan Anh Le ◽  
An Thao Huynh ◽  
Namshik Ahn
Keyword(s):  
Compressive Strength ◽  
Sodium Hydroxide ◽  
Carbon Dioxide Emissions ◽  
Building Materials ◽  
Sodium Hydroxide Solution ◽  
Curing Temperature ◽  
Geopolymer Concrete ◽  
Curing Time ◽  
Curing Conditions ◽  
Alkali Hydroxide

Geopolymer concrete is known as an alternative to Portland cement, with low carbon dioxide emissions compared with the conventional building materials. In this research, the influence of curing conditions and alkali hydroxide were investigated, using curing temperatures between 40 to 100℃, curing times from 4 to 12 hours, and various types of hydroxide and concentrations of sodium hydroxide solution. Geopolymerization needs energy and time to occur, and higher curing temperatures resulted in larger compressive strength, while longer curing times resulted in higher compressive strength. At the same curing temperature, longer curing time resulted in a higher compressive strength because the longer curing time extends the chemical reaction. For geopolymer concrete, sodium hydroxide is a better property than potassium hydroxide, because the atomic size of sodium anion is smaller than potassium. Further, the strength of concrete increased when the concentration of sodium hydroxide increased. In conclusion, geopolymer concrete is suitable for traditional building materials. Finding renewable materials to satisfy the increasing demand for building structures will be the primary challenge in future.

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