Soluble pozzolanic materials from coal bottom ash as cement replacement material

Nowadays, intensive research in production of highly reactive pozzolanic materials from industrial waste to replace cement is crucial. This action expected to increase industrial waste recycling rate and at the same time reduce extraction of non-renewable resources of limestone. Unique characteristics of coal bottom ash as one of the industrial based pozzolan gained less popularity because of its low reactivity and heavy metal leaching due to conventional method used for disposal. Therefore, an alternative approach was deliberated in this research to utilize coal bottom ash into soluble form and enhance the quality of bottom ash as pozzolanic material. Coal bottom ash after the acid washing with optimum parameter was then undergoes solution-gelification process with various alkali based solution for 2 hours soaking durations. The conversion of coal bottom ash into soluble silica in this study demonstrates good pozzolanic performance in a state of siliceous gel pozzolan compared to the raw ones. 5% of cement replacement by soluble silica from CBA shows good strength development from early and later age. The physical dispersion effect is the cumulative effect of enhancement cement hydration due to the availability of increased the nucleation sites on soluble silica particles

Pemanfaatan Bottom Ash Dan Fly Ash Tipe C Sebagai Bahan Pengganti Dalam Pembuatan Paving Block

PT. PLTU Paiton menghasilkan 7.5 ton fly ash dan 2.5 ton bottom ash setiap jam. Pemanfaatan bottom ash masih sangat minimal, sehingga mengakibatkkan timbunan bottom ash yang semakin meningkat, dan cendrung mencemari lingkungan dan kesehatan. Berdasarkan alasan tersebut maka perlu adanya USAha untuk memanfaatkan limbah batu bara, salah satunya melalui pembuatan paving block. Sampel tahap pertama terbuat dari campuran semen dan bottom ash (lolos ayakan 2 atau 5 mm) dengan perbandingan massa 1:3, 1:4, dan 1:5. Komposisi campuran dengan properti paling baik (kuat tekan, serapan air, dan ketahanan aus) dimodifikasi dalam tahap kedua, yaitu mengganti porsi semen sebanyak 10, 20, 30, 40, 50, 60, 70, dan 80% dengan fly ash tipe C. Pada tahap ketiga, sampel dengan 30 dan 50% fly ash dibuat kembali menggunakan gabungan bottom ash lolos ayakan 5 dan 10 mm. Hasil penelitian menunjukkan bahwa setelah curing selama 28 hari, penggunaan bottom ash lolos ayakan 5 mm menghasilkan paving dengan properti lebih baik dibanding bottom ash lolos ayakan 2mm. Penambahan jumlah bottom ash menurunkan properti paving dan penggantian fly ash atas semen paling optimum adalah sebesar 20-50%. Penggunaan 50% bottom ash lolos ayakan 10 mm dan 50% lolos ayakan 5 mm meningkatkan properti paving dengan kuat tekan melampaui 40 MPa

Penggunaan Bottom Ash Sebagai Pengganti Agregat Halus Pada Mortar Hvfa

Bottom ash adalah material limbah PLTU yang melimpah dan kurang dimanfaatkan. Terdapat potensi pemanfaatan bottom ash sebagai agregat halus dalam campuran beton. Dalam penelitian ini, bottom ash diberi treatment ayak dan tumbuk untuk digunakan sebagai pengganti pasir dalam campuran beton. Hal pertama yang dilakukan adalah pengujian karateristik fisik dan kimiawi dari bottom ash. Dilakukan pengujian water content, sieve analysis, fineness modulus, dan berat isi dari pasir dan bottom ash yang digunakan. Pengujian kuat tekan dan flowability pada mortar high volume fly ash (HVFA) menggunakan bottom ash sesudah diberi treatment dibandingkan dengan mortar HVFA yang menggunakan pasir. Pengujian tersebut dijadikan tolak ukur untuk mengevaluasi pengaruh penggantian bottom ash terhadap pasir. Dari penelitian ini, dapat dievaluasi bahwa Perubahan kekuatan dan flowability dari mortar dengan 100% penggantian pasir dengan bottom ash bervariasi. Bottom ash yang diayak dengan halus memberikan penurunan kekuatan dan flowability terbanyak, sedangkan bottom ash yang ditumbuk memberikan hasil yang bertolak belakang

Pengaruh Campuran Kadar Bottom Ash Dan Lama Perendaman Air Laut Terhadap Pola, Lebar Dan Kedalaman Retak Pada Balok

Dari pengujian ini didapatkan bahwa terdapat pengaruh variasi campuran bottom ash dimana nilai kuat tekan yang paling tinggi terjadi pada campuran bottom ash 10%. Demikian juga halnya dengan hasil pengamatan pola retak, dimana hingga terjadi kegagalan geser pada balok uji dengan keruntuhan geser. Hal ini terjadi pada balok beton dengan keruntuhan geser perendaman 28 hari campuran bottom ash 10%. Perbedaan kemunculan retak awal pada benda uji dengan keruntuhan geser perendaman 14 hari menunjukkan pengaruh variasi kadar campuran bottom ash terhadap lebar retak. Berikut juga dengan besar nilai lebar retak maksimum pada balok dengan keruntuhan lentur durasi perendaman 28 hari yang dianalisis oleh peneliti. Yaitu, 0,16 mm pada campuran bottom ash 0%; 0,10 mm pada campuran bottom ash 10%; 0,12 mm pada campuran bottom ash 20% dan sebesar 0,13 mm pada campuran bottom ash 25%. Variasi durasi perendaman air laut juga memberikan pengaruh yang cukup signifikan. Seperti pada keruntuhan lentur perendaman 14 hari yaitu dengan lebar retak 0,10 mm untuk campuran bottom ash 0%; 0,13 mm untuk campuran bottom ash 10%; 0,14 mm untuk campuran bottom ash 20% dan 0,12 mm untuk campuran bottom ash 25%. Dengan lebar retak maksimum yang diijinkan oleh ACI Code untuk daerah basah khususnya dalam lingkup air laut adalah 0.15 mm dan sering dibulatkan menjadi 0.20 mm, sehingga hasil penelitian ini masih bisa digunakan sebagai acuan untuk penelitian selanjutnya. Keterbatasan alat uji menjadi masalah utama dalam pengukuran kedalaman retak. Hal ini menyebabkan tidak dapat dihimpunnya data dengan baik

Water absorption and salt attack resistance of coal ash brick made of different percentage of foam content

Coal ash which constitute of fly ash and bottom ash were proved to be used as main component in brick production. However, published work on the coal ash brick with addition of foam in order to produce lightweight brick is still lacking. This thesis reports the effect of variation in foam content in coal ash brick on the density, water absorption and salt attack resistance. Comparison of those parameters was made between the coal ash bricks and conventional brick. The coal ash brick mixes were formulated using industrial by-product, ground granulated blastfurnace slag (GGBS) which is activated with an alkaline (hydrated lime or Portland cement) combined with coal ash from coal-fired thermal power plant. The blended binder comprising of hydrated lime (HL) – GGBS and Portland cement (PC) –GGBS were used to stabilize the coal ash brick. Foam was used to produce lightweight brick. The percentage of foam added to the brick mixes are 25%, 50% and 75%. A total of sixty (60) brick specimen subjected to ten (10) series of mix proportion were cast and put in air curing condition for at least 28 days before testing. The density measurement in accordance with AS/NZS 4456.8, water absorption test in accordance with BS EN 772-21 and salt attack resistance in accordance with AS/NZS 4456.10 were evaluated on the brick specimens. The results indicated that the density of coal ash brick decreases with the increase in foam content. Also for bricks composed of both blended binder, the water absorption were directly proportional to the amount of foam. Thus, the water absorption of foam brick increases with the reduction in density. Higher foam content leads increase of pores and capillaries in brick structure, therefore the brick become weaker to resist on salt attack. XRD pattern of formed brick with 75% of foam addition on HL-GGBS coal ash brick portrays ettringite formation were attributed to disruption of brick structure. The use of coal ash with HL–GGBS and PC-GGBS combination as binder agent has been observed to be lightweight, low in water absorption, and advantageous in protection to salt attack compare to the conventional brick. The optimum proportion respected to the foam content is 50% in balance condition with approximately 1-2% of mass loss due to salt attack, 12-13% of water absorption and density significantly reduced to 1600kg/m3 . Keywords – fly ash; bottom ash; hydrated lime; Portland cement; ground granulated blastfurnace slag (GGBS); foam; brick; density; water absorption; salt attack resistanc

The use of bottom ash for replacing fine aggregate in concrete paving blocks

Bottom ash that results from coal burning for electrical generation is still much underutilized in Indonesia and it is necessary to increase the usage of this waste. The manufacture of paving blocks using bottom ash, which is normally associated with high water absorption due to its high porosity and carbon content, was examined in this study with the aim to increase the usage of this waste material. The study was done in three phases: (1) the mixture of cement and bottom ash passing sieves of 2 and 5 mm were done with ratios of 1:3, 1:4, and 1:5; from the best proportion, fly ash was used to replace the cement material from 10�80%, and (3) samples with 30% and 50% fly ash replacement ratios were used in combination with 5 mm and 10 mm sieved bottom ash. Compressive strength, water absorption, and abrasion resistance tests were conducted to assess the properties of the resultant paving block. From the result, bottom ash is used to replace natural sand in making paving blocks. By optimizing the particle packing density and using fly ash as a cement replacement, the compressive strength of paving blocks can exceed 40 MPa

Pembuatan Briket dari Bottom Ash dan Arang Tempurung Kelapa sebagai Sumber Energi Alternatif

Limited availability of energy resources, especially fuel unrenewable become a serious threat to society. The use of coal as an energy source replacement for fossil fuels is very beneficial, but on the other side can cause problems such as coal ash. Coal ash is composed of bottom ash (bottom ash).Through research, it is known that the bottom ash can be processed into charcoal, when mixed with coconut shell, plus a binder and further processing can be made into briquettes. It can be used as an alternative fuel, bottom ash and coconut shell can give positive impact for the environment.This study was conducted with a variety of compositions between bottom ash and coconut shell charcoal. The treatment uses ratio of 100%: 0%; 80%: 20%; 60%: 40%; 50%: 50%; 40%: 60%; 20%: 80%; 0%: 100%. The results showed that the optimum variation of briquettes is a variation of 20% bottom ash and 80% coconut shell charcoal, this briquettes has a water content of 3.45%, ash content of 17.32%, calorific value of 7945.72 cal/g, compressive stength of 2.18 kg/cm2, CO 105 mg/Nm3, Cu 29.83 mg/l (745,6 x 103 µg/g) and Zn 32.99 mg/l (824,8 x 103 µg/g). The result of the briquttes characteristics test showed that with increasing amounts of coconut shell charcoal can increase the moisture content and calorific value, and be able to lower ash content and compressive strength

Karakteristik Mekanis dari Campuran Abu Terbang dan Abu Dasar dalam Geoteknik

Generally, coal are used for fuel by industry factory at Indonesia. Coal burning produce two of kind waste, that is fly ash and bottom ash. Utilization of coal waste is not optimal yet at this time. This research aims to find out optimum percentage from fly ash and bottom ash mixed by mechanical strength and to know curing effect for 0 and 28 days. The result of proctor standard is increasing proportion bottom ash content on fly ash and bottom ash mixed, then increased dry density maximum while optimum moisture content is decreased. CBR value is increased with increasing bottom ash content. From UCS test, value shear strength (cu) is decreased because increasing bottom ash content. Value from CBR, UCS and Triaxial test is increased after curing for 28 days

Pemanfaatan Bottom Ash Batubara Menjadi Produk Briket Dengan Penambahan Arang Daun Jati

The use of coal as the primary fossil fuels in Indonesia are increasingly widespread. Now, the use of coal is not only used for the power plant but also a wide range of industries. Resulting from the use of coal bottom ash which can still be used because they save the calorific value for alternative fuel that is becoming briquette product. Through research it is known that the bottom ash can be processed into briquettes products with the addition of teak leaves charcoal to improve its quality.This study was conducted with a variety of compositions between bottom ash and teak leaves charcoal. The treatment uses ratio of coal bottom ash : teak leaves charcoal 0%:100%, 20%:80%, 40%:60%, 50%:50%, 60%:40%, 80%:20% and 100%:0%. The results showed that the optimum variation of briquettes is a variation of 20 % coal bottom ash and 80% teak leaves charcoal, this briquettes has a water content of 4,052 %,ash content of 36,358 %, calorific value of 4.520 cal/g, compressive stength of 2,383 kg/cm2,CO 54 ppm or 61,84 mg/Nm3,Cu 0,85 µg/g and Zn 1,21 µg/g.The result of the briquttes characteristics test showed that with increasing amounts of teak leaves charcoal can increase the moisture content and calorific value, and be able to lower ash content and compressive strength