Development of Fly Ash Based Geopolymer as Erosion Mitigation Coating

2014 ◽  
Vol 699 ◽  
pp. 342-347
Author(s):  
Noor Hafizah Ramli Yusof ◽  
Rashidah Mohamed Hamidi ◽  
Zakaria Man ◽  
Khairun Azizi Azizli ◽  
Mohd Fadhil Nuruddin

Loss of durability of concrete materials in sewage and chemical treatment facilities exposed to acidic environments is a key issue that affects the life cycle performance. Applications of organic coating such as epoxy and acrylic usually covers the concrete surface by physical addition normally failed to act as an effective coating due to debonding when the organic coating absorbs water. In this work, geopolymer was used as alternative material for concrete coating. Preparation of geopolymer involved fly ash, a materials containing high aluminosilicate and calcium mixed with various concentrations (6, 8 and 12M) of sodium hydroxide (NaOH). Subsequently, all samples were tested and analysed through compressive strength test and gel time. Geopolymers synthesised from 12M NaOH concentration exhibited high compressive strength and low gel time, hence was chosen as a coating for the concretes for the erosion evaluation. Results show that, concretes coated with geopolymers yielded low percentage of mass loss compared to the uncoated concretes. This suggest that geopolymers has high potential to be used as erosion mitigation coating to prevent the concretes from degrading due to the acidic environment.

2020 ◽  
Vol 165 ◽  
pp. 03029
Author(s):  
Jiangong Yang

Through comparatively analyzing the impermeability and compressive strength test data of nano CaCO3 concrete with different content, this paper puts forward the method of optimizing the durability of nano CaCO3 concrete, and studies the influence of the content of fly ash on the durability of nano CaCO3 concrete on this basis, so as to provide a reference for improving the durability of concrete, so as to improve the recycling and reusing efficiency of building materials, and accelerate the practical application of nano CaCO3 concrete in engineering.


2011 ◽  
Vol 255-260 ◽  
pp. 3404-3410
Author(s):  
Shuang Xi Li ◽  
An Quan Xu ◽  
Xin Jun Tang ◽  
Quan Hu

It takes on the technical and economic double benefits that fly ash taking the place of cement. However, water/binder of modern concrete is generally low; the research on the concrete performance which is based on large water/binder is no longer suitable for analysis of modern concrete. As to this problem, using different proportions of W/B and FA dosage as influencing factors, specimen is compounded for the compressive strength test. Then, mechanical properties of HPC are studied systematically. Based on this, macro-performance is analyzed from a micro-mechanism point of view through taking the electron micrograph. As the study shows, strength of HPC mixed with fly ash has low characteristics at early period while high ones at later period. At later hydration, fly ash effect plays a significant role, the growth rate of concrete strength increases as the increase of FA dosage. Compressive strength of concrete decreases as the increase of W/B and FA dosage. When the W/B is high, compressive strength is not sensitive to the change of W/B and FA dosage; but when the W/B decreases from 0.30 to 0.25, the concrete strength transition occurs. The influence of W/B on concrete compressive strength is more significant than that of the FA dosage; in the preparation of HPC, fly ash can be added more and cement is added less relatively by decreasing the W/B, displaying the role of micro-aggregate filling and modification, improving the strength and other performance of concrete. The study on micro-mechanism proves well the macro-phenomena above.


2018 ◽  
Vol 195 ◽  
pp. 01023 ◽  
Author(s):  
Ari Widayanti ◽  
Ria Asih Aryani Soemitro ◽  
Hitapriya Suprayitno ◽  
Januarti Jaya Ekaputri

Fly ash is a by-product obtained from coal combustion process. Some of the utilization of fly ash is to produce geopolymer products which have high compressive strength, fire, chemical resistance. This paper proposes fly ash from unit 1-7 Suralaya Power Plant Indonesia. The aims of this study are to obtain characterization of fly ash and mechanical properties of geopolymer paste based on variations of the alkali activator ratio. The method was based on previous research and laboratory investigation. XRF and compressive strength were analysed in this study. Alkali activator was obtained from NaOH and Na2SiO3 mixture. The ratio of Na2SiO3 to NaOH was in the range of 0.5-2.5. Geopolymer paste was casted in acrylic cylinders with a diameter of 2 cm and a height of 4 cm. The curing was conducted at room temperature until the day for the compressive strength test at 28 days. The result showed that the fly ash is classified as F class. Increasing the alkali activator ratio influenced the strength. The best composition of geopolymer paste is made with NaOH 8M, and the mass ratio of Na2SiO3 to NaOH is 2.5. This composition produced compressive strength of 98.6 MPa.


Natural Sand, which is being used extensively for all types of construction activities, is getting scarce now and many researchers have been put to task of testing other materials like manufactured sand for their usability in civil works. Present study aims at using the locally available soil for producing earth blocks. The materials like Auto aerated clay waste, manufactured sand are used in different proportions to see the possibility as a replacement for natural sand. Both the materials were used in proportion range of 35-65% along with 8% cement as a stabilizing agent. The cube compressive strength test was performed on soaked samples after 7 days and 28 days. It has been concluded from the result that the manufactured sand is cheap alternative material to replace natural sand


Author(s):  
B Anitha Rani V Bhargavi,

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).


2010 ◽  
Vol 113-116 ◽  
pp. 1293-1296
Author(s):  
Yu Zhu ◽  
Ying Zi Yang ◽  
Hong Wei Deng ◽  
Yan Yao

In order to investigate the mechanical properties of cementitious composites (ECC) cured at 60°C, four-point bending test and compressive strength test are employed to analyze the effect of fly ash on the properties of ECC. The replacement ratio of cement with fly ash is 50%, 70% and 80%, respectively. The test results indicate that ECC with high volume fly ash still remain the characteristic of pseudo-strain hardening and the deflection of ECC increases remarkably by adding more fly ash. The observations of ECC indicate that the crack width is relatively smaller for higher volume fly ash ECC. Meanwhile, compressive strength of ECC specimens with 80% fly ash can reach to 70MPa. This is helpful to produce precast ECC with high volume of fly ash.


2015 ◽  
Vol 744-746 ◽  
pp. 628-631
Author(s):  
Yi Xiang Chen ◽  
Kai Xi An ◽  
Ke Xin Zhou ◽  
Chen Hao Xu

In order to reveal the effect of type of admixture and its content on the strength of stabilized soil, this paper uses the sludge as raw soil and cement, fly ash as curing agent, and analyzes the strength characteristics of samples mixed stabilized according to certain content. Using the unconfined compressive strength test, the compressive strength of the samples is tested. The effect of curing agent type and its content on the compressive strength is investigated. From the experimental results, it can be seen that the content of cement and fly ash has much effect on the strength. The conclusions obtained can have some conference values on the foundation treatment and reuse of waste resources utilization.


2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Agus Maryoto ◽  
Buntara Sthenly Gan ◽  
Nor Intang Setyo Hermanto ◽  
Rachmad Setijadi

This study aims to determine the effect of calcium stearate on concrete. Three kinds of concrete quality are studied, namely, 20, 30, and 40 MPa. Tests performed in the laboratory comprise a compressive strength test and an infiltration test of chloride ion content. The specimens used were cylinders with a diameter of 150 mm and height of 300 mm. The chloride ion infiltration test was carried out on a cube with sides of 150 mm. The infiltration of ions into the concrete was examined at depths of 1, 2, 4, 6, and 8 cm. Four dosages of calcium stearate were added to the concrete, namely, 0, 0.25, 1.27, and 2.53% for 20 MPa concrete; 0, 0.21, 1.07, and 2.48% for 30 MPa concrete; and 0, 0.19, 0.90, and 1.87% for 40 MPa concrete. The results of compressive strength tests indicate that the amount of calcium stearate that could be safely applied to the concrete was 0.25% of the weight of cement. On the other hand, the infiltration of chloride ions at a depth of 6 cm from the unprotected concrete surface decreased by 87, 69, and 113% for the 20, 30, and 40 MPa concrete, respectively, compared to concrete without calcium stearate. The test shows that the use of calcium stearate in concrete significantly increases its resistivity against corrosion attacks because, in the absence of chloride ions, the process of corrosion does not take place in the concrete.


2018 ◽  
Vol 917 ◽  
pp. 297-302
Author(s):  
Jul Endawati ◽  
R. Utami ◽  
Rochaeti

Fly ash as a pozzolanic waste material can be utilized to substitute part of Portland cement in concrete mixture. The concrete paving industry utilizes the fly ash up to 50% (by weight) of the total binder. This study aims to obtain the characteristics of fly ash applications for pervious concrete. The composition of the binder developed based on the optimal proportion of fly ash from the previous study and the maximum of fly ash percentage used by the local paving industry in general. Other mix variations were made of the same binder composition with the addition of 6% of fine aggregates. The compressive strength of pervious concrete which binder composed of 63% portland cemet composite-25% fly ash-12% silica fume gained at 28 days, was not much different from the compressive strength of the pervious concrete without fine aggregate and with the binder composition of 50% FA-50% PCC and 0% SF. The value of the compressive strength test of the pervious concrete without fine aggregate is still within the range of compressive strength values ​​according to the ACI 522 R-10. The permeability rate of the pervious concrete is in the range of permeability research result of Chopra, 2013 (0.97 ÷ 1.90 cm/sec), but still higher compared to permeability rate gained by Dewoolkar, 2009 (0.83 ÷ 0.98 cm/sec).


2016 ◽  
Vol 1 (02) ◽  
Author(s):  
Krisna Adhitya Wardhana ◽  
Sri Purwati ◽  
Saepulloh , ◽  
Toni Rachmanto

Deinking sludge and coal fly ash are classified as hazardous wastes that have to be treated before disposed in landfill. Solidification is an alternative treatment to prevent hazardous materials release to the environment. The research was conducted to find solidification combination formula of deinking sludge and coal fly ash that pass compressive strength test (>10ton/m2) and paint filter test so it can be disposed to landfill. The concretes were made from cement and aggregate (50% deinking sludge and 50% fly ash) on range combination 1:11 - 1:20. In addition, based on pozzolanic characteristic of fly ash, concretes without cement was made. The results showed that solidification products with combination 1:11 - 1:20 have compressive strength that exceed the regulation and passed paint filter test. Combination of 50% deinking sludge and 50% coal fly ash without portland cement addition had compressive strength that met requirement for landfill disposal.Key words : deinking sludge, fly ash, solidification, landfill ABSTRAKDeinking sludge dan fly ash batubara termasuk kedalam kategori limbah B-3 yang harus diolah terlebih dahulu sebelum ditimbun di landfill. Proses solidifikasi adalah salah satu pengolahan untuk mencegah tersebarnya kandungan limbah B-3 ke lingkungan. Tujuan dari penelitian ini adalah menentukan formulasi solidifikasi kombinasi deinking sludge dengan fly ash batubara yang memenuhi persyaratan kuat tekan (> 10 ton/m2) dan uji paint filter sehingga dapat ditimbun di landfill. Penelitian ini dilakukan dengan variasi perbandingan semen terhadap agregat (50% fly ash dan 50% deinking sludge) mulai dari 1:11 sampai dengan 1:20 dan juga dilakukan perlakuan agregat tanpa semen. Hasil penelitian menunjukkan bahwa komposisi 1:11 s/d 1:20 memiliki nilai kuat tekan yang jauh melebihi persyaratan dan lolos uji paint filter. Sedangkan hasil dari perlakuan tanpa semen menunjukkan bahwa kombinasi 50% deinking sludge dan 50% fly ash batubara telah memiliki nilai kuat tekan yang cukup besar dan memenuhi persyaratan penimbunan di landfill.Kata kunci : deinking sludge, fly ash batubara, solidifikasi, landfill 


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