scholarly journals Comparison of The Compressive Strength and The Microstructure of Metakaolin Metastar and Metakaolin Bangka as Additive in Ordinary Portland Cement

2018 ◽  
Vol 67 ◽  
pp. 03023 ◽  
Author(s):  
Sotya Astutiningsih ◽  
Widyaningsih Sura ◽  
Ahmad Zakiyuddin

Various This paper presents the results of the investigation on the use of Metakaolin (Al2Si2O2) as a supplementary cementing materials to improve the strength of cement. The most effective way to increase the strength of cement is the substitution of a proportion of cement with supplementary cementing materials. One of them was Metakaolin. Metakaolin was produced by thermal treatment calcination from Kaolin at 600-800 Celcius and has highest alumina and silicate purity. By added Metakaolin to Portland Cement type I (OPC), the amount of Calcium Silicate Hydrate (CSH) will increase through binding with Calcium Hydroxide (CaOH). There were two kinds of Metakaolin used in this investigation, commercial metakaolin named Metakaolin Metastar compared with Metakaolin Bangka which derived from Indonesia local resources, Bangka Island. Four Metakaolin replacement levels were employed in this investigation: 5%, 0%, 15%, and 20% with water per cement ratio 0.35, 0.40, and 0.50 both of Metakaolin Metastar and Metakaolin Bangka. The cement pastes cured at room temperature for 7, 14, and 28 days. The mechanical strength examined by compressive strength test, the microstructure were examined by SEM-EDS. The results of the study revealed both Metakaolin Metastar and Metakaolin Bangka enhanced the compressive strength of OPC. The most appropriate strength was obtained for a substitution of 20% metakaolin metastar which had 46,15% higher than OPC and 5% metakaolin Bangka which had 39,06% higher than OPC. The hydration rate was examined by Thermal Analysis Monitor. The results indicated that metakaolin metastar released higher heat than metakaolin Bangka. It can be concluded that Metakaolin metastar was more effective than metakaolin Bangka as additive in OPC.

2020 ◽  
Vol 11 (2) ◽  
pp. 61-71
Author(s):  
Yulizar Yusuf ◽  
Vivin Firman Savitri ◽  
Hermansyah Aziz

The aim of this study is to utilize fly ash from various sources on chemical and physical properties of cement type I (OPC). Utilization of fly ash can improve the strengthness of the cement. It can reduce the waste of fly ash by utilization into cement process. The procedure has been carried out on cement type I (OPC) with the addition of fly ash additives from various sources with concentration variations such as 10% and 20%. Utilization of fly ash as additives substance in cement works to improve the quality of cement. The main parameter in determining the quality of cement is determined by the compressive strength. The results of the compressive strength test showed that the addition of fly ash with a concentration of 10% had a higher effect on the compressive strength than the addition of a concentration of 20%. 5 types fly ash from various sources, fly ash from PT Sinar Mas gives greater compressive strength at 28 days. the addition of fly ash additives to OPC cement mixture has chemical and physical properties which are not much different from properties of PCC cement.


2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Mario Tanomaru-Filho ◽  
Vanessa Morales ◽  
Guilherme F. da Silva ◽  
Roberta Bosso ◽  
José M. S. N. Reis ◽  
...  

Objective. The aim of this study was to evaluate the compressive strength and setting time of MTA and Portland cement (PC) associated with bismuth oxide (BO), zirconium oxide (ZO), calcium tungstate (CT), and strontium carbonate (SC). Methods. For the compressive strength test, specimens were evaluated in an EMIC DL 2000 apparatus at 0.5 mm/min speed. For evaluation of setting time, each material was analyzed using Gilmore-type needles. The statistical analysis was performed with ANOVA and the Tukey tests, at 5% significance. Results. After 24 hours, the highest values were found for PC and PC + ZO. At 21 days, PC + BO showed the lowest compressive strength among all the groups. The initial setting time was greater for PC. The final setting time was greater for PC and PC + CT, and MTA had the lowest among the evaluated materials (P<0.05). Conclusion. The results showed that all radiopacifying agents tested may potentially be used in association with PC to replace BO.


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 


2016 ◽  
Vol 841 ◽  
pp. 7-15 ◽  
Author(s):  
Himawan Tri Bayu Murti Petrus ◽  
Joshepine Hulu ◽  
Gede S.P. Dalton ◽  
Elsa Malinda ◽  
Rizal Agung Prakosa

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.


2019 ◽  
Vol 11 (1) ◽  
pp. 7-12
Author(s):  
Hotmalina Manullang ◽  
Fepy Supriani ◽  
Agustin Gunawan

Mortar is a mixture of adhesive (Portland cement and limestone), sand, and water with a certain composition. Mortar is used in structural and nonstructural constructions. This research uses sawdust charcoal as cement addition because in similar research mention that wood charcoal contains silica. This research was aimed to know the value of compressive strength of the mortar (1:3 and 1:5) by using sawdust charcoal as cement addition. The method of manufacture and testing compressive strength of mortar refers to SNI 03-6825-2002. The mortar specimens is cube shaped with side 50 mm and the total of specimens have 112 mortar test specimens. Variations of sawdust charcoal used were 2,5%, 5%, 7,5%, 10%, 12,5% and 15% of the weight of cement. The range of initial flow values used are 105% - 115 (SNI 03-6882-2002). The specimens were soaked for 26 days and compressive strength test of mortar was performed at 28 days. The test results showed that the compressive strength value of normal mortar (1:3) of 25,09 MPa, the value of compressive strength of variation mortar 2,5%, 5%, 7,5%, 10%, 12,5% and 15% respectively are 25,89 MPa, 26,93 MPa, 27,84 MPa, 25,58 MPa, 20,68 MPa and 17,24 MPa. The value of compressive strength of normal mortar (1:5) of 15,48 MPa, the value of compressive strength of mortar variation 2,5%, 5%, 7,5%, 10%, 12,5% and 15% respectively are 15,83 MPa, 16,24 MPa, 17,01 MPa, 15,59 MPa, 14,45 MPa dan 12,26 MPa. The highest increase of compressive strength value in mixture 1:3 was variation 7,5% by 10,94% and mixture 1:5 was variation 7,5% by 9,90% from the compressive strength value of normal mortar.


2020 ◽  
Vol 10 (1) ◽  
pp. 9-24 ◽  
Author(s):  
Nilankham Banchong ◽  
Warangkana Saengsoy ◽  
Somnuk Tangtermsirikul

The use of fly ash in concrete improves several characteristics of conventional cement-based pastes, mortars, and concrete such as reduces heat of hydration, increases strength in long-term and enhances durability. However, types and volume of fly ash affect behavior of resulting pastes, mortars and concrete. In this study, the characteristics of pastes, mortars, and concrete with 20% and 30% binder replacement with a Hongsa fly ash from Laos (FAH3) and two fly ashes from Thailand (FAM and FAB) were studied. Further, mechanical and durability properties of Hongsa fly ash mortars and concrete are investigated through specific gravity, Blaine fineness, normal consistency, setting times, water requirement, strength index, slump and slump retention, compressive strength of concrete with a fixed slump, compressive strength of concrete with a fixed w/b of 0.5, semi-adiabatic temperature, total shrinkage, carbonation depth, H2SO4 acid resistance, rapid chloride penetration (RCP) and chloride distribution. The experimental results show that the Hongsa fly ash contains large amount of non-spherical particles with coarse cavities, leading to high surface area and high Blaine fineness value. Accordingly, Hongsa fly ash was found to have high water requirement. In comparison to the ordinary Portland cement type I (OPC) and Mae Moh fly ash (FAM), the Hongsa fly ash was found to generate lower heat. As a result, the Hongsa fly ash shows its potential in the application of mass concrete. Similarly, the Hongsa fly ash mortar exhibited the lowest carbonation depth when compared to the FAM and FAB mortars. In term of RCPT and chloride distribution test, the Hongsa fly ash concrete shows the lowest Cl⁻ penetrability when compared with Portland cement type I (OPC) concrete, FAM and FAB concretes. Based on the experimental results, the Hongsa fly ash was found to be applicable in concrete works.


2018 ◽  
Vol 67 ◽  
pp. 03022
Author(s):  
Sotya Astutiningsih ◽  
Dicky Tambun ◽  
Ahmad Zakiyuddin

Various aluminosilicate material have been used as precursor for geopolymer. Geopolymer gets its strength from the polycondensation of silicate and alumina. Metakaolin, calcinated kaolin, is pozzolan with the highest alumina and silicate purity. Indonesia, especially Bangka Island, has a large amount of kaolin deposit that being sold at low price. This price could be increased ten times when being sold as metakaolin. This study aimed to compare mechanical and metallurgical properties of commercial metakaolin and Bangka kaolin which calcinated at 700°C. Both metakaolins reacted with NaOH and waterglass as the activator followed by curing at room temperature for 7, 14 and 28 days and elevated temperature of 60°C for 4, 12 and 24 hours. Mechanical properties will be examined by compressive strength and flexural strength test, while the metallurgical properties will be evaluated with SEM, and TAM. The results of the mechanical test will be used to determine which geopolymer will perform well with the microstructure and thermal activity to support the finding. These attempts will be done in order to improve the properties of Bangka metakaolin geopolymer superior to commercial metakaolin.


2018 ◽  
Vol 203 ◽  
pp. 06022
Author(s):  
Salmia Beddu ◽  
Daud Mohamad ◽  
Fadzli Mohamed Nazri ◽  
Siti Nabihah Sadon ◽  
Mohamed Galal Elshawesh

This study investigates the self-curing concrete using baby polymer diapers as substitute method of curing process in order to improve mechanical and physical properties of concrete. Three different proportion of baby polymer diapers which are 1%, 3% and 5% were mix with concrete. Slump, compressive strength and drying shrinkage test were performed in order to study the workability, strength and durability of the concrete. All concrete were tested for 1, 3, 7, 14, and 28 days for drying shrinkage test. Meanwhile, all concrete were test at 3, 7 and 28 days for compressive strength test. Compressive strength of concrete containing 5% baby polymer diapers show the highest strength at 28 days compared to others percentage. Thus, it indicates that application of baby polymer diaper as self-cure agent can improve the concrete performances.


2007 ◽  
Vol 72 (6) ◽  
pp. 591-604 ◽  
Author(s):  
Gordana Stefanovic ◽  
Ljubica Cojbasic ◽  
Zivko Sekulic ◽  
Srdjan Matijasevic

Fly ash (FA) can be used in cement mixtures with certain limitations. The problem of the mentioned mixtures lies in the insufficient activity of the particles of FA in the reactions which are important for the establishment of the mechanical characteristics of cement. This is particularly true for the hydration reactions. As a result of this, cement pastes formed by mixing ash and clinker have worse characteristics compared to those of pure Portland cement (PC), especially in the early period of setting. As is well known, FA can be a good solution for the neutralization of the negative effects generated due to the creation of free Ca(OH)2 during the hydration of PC, provided that the problems with the low activity of FAare overcome. For the experiments in this study, a mixture of Portland cement and fly ash was used, the content of ash in the mixture being 30 % and 50 %. Mechanical activation was performed in a vibrating ring mill. The goal of this study was to demonstrate, through experimental results, that during the mechanical activation of a PC and FA mixture, the components in the mixture which mostly affect the direction, rate and range of hydration reactions occurring in the mixture had been activated. The values of the compressive strength of the activated and non-activated mixtures and the changes of their specific surface area proved that during the grinding process, the mixture PC+FA had been mechanically activated. The highest increase of compressive strength was achieved in the early period of setting, which indicates an improvement in the early hydration of the mixture. XRD, DTA and TG analyses showed that the alite (C3S) and belite (C2S) from the PC and a part of the fly ash were activated. .


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