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Penggunaan fly ash sebagai bahan tambahan untuk menggantikan sebagian semen merupakan salah satu hal untuk mendorong penggunaan material alternatif. Penelitian ini mengkaji pengaruh persentase substitusi fly ash sebesar 10%, 30%, dan 50% dengan penambahan zat aditif superplasticizer sikament-NN (Tipe F) dengan dosis 1,2% terhadap kemudahan pengerjaan (workability) dan kekuatan tekan beton. Kinerja beton dianalisis berdasarkan kekuatan tekannya pada hari ke-28 dab kelancaran kerjanya berdasarkan slump. Hasil penelitian ini menunjukan bahwa kombinasi penggunaan fly ash dan superplasticizer sikament-NN (Tipe F) dapat meningkatkan kemudahan adukan, dengan nilai slump maksimum mencapai 14,3 cm pada presentase fly ash 50%. Namun, peningkatan kelacakan ini berbanding terbalik dengan kekuatan tekan yang konsisten menurun seiring dengan peningkatan penambahan fly ash. Nilai kuat tekan maksimum dicapai oleh campuran beton yang hanya menggunakan superplasticizer tanpa fly ash sebesar 320,50 kg/cm2, sementara nilai yang optimal ditemukan pada variasi persentase 10% dengan penambahan superplasticizer 1,2% menghasilkan kuat tekan sebesar 307,65 kg/cm2, sehingga penggunaan kombinasi ini diharapkan dapat memberikan kontribusi efisiensi bagi rekayasa sipil.

Modern infrastructure development often involves the use of mass concrete in large structural elements such as pile caps and foundations. However, massive concrete volumes trigger a significant temperature increase due to the heat of hydration that is difficult to dissipate, posing a risk of thermal stress and structural cracking. This study aims to analyze the temperature rise behavior of mass concrete and evaluate the effectiveness of combining chilled water and fly ash substitution in minimizing these thermal cracking risks.The research method employs a quantitative approach through laboratory testing at PT Adhimix RMC Plant Kaligawe. Specimen blocks measuring 40 x 40 x 100 cm were divided into three variations: normal concrete (BN), concrete with chilled water and 15% fly ash (BAF), and concrete with 25% fly ash (BF). Temperature was monitored using thermocouples at the core and surface for 14 days, then validated using the Portland Cement Association (PCA) formula. The results indicate that the integration of chilled water with 15% fly ash and the use of 25% fly ash significantly controlled extreme temperature surges at the 5th hour. The combination of chilled water and 15% fly ash produced the lowest core temperature of 37.3°C, far below the control concrete which reached 62.4°C. This proves that the combination of precooling methods and fly ash substitution is effective in reducing the heat of hydration during the early hardening period, although the use of 25% fly ash was found to be more stable in maintaining mass concrete temperature.

Self-Compacting Concrete (SCC) requires a high cement content, which contributes to increased carbon emissions; therefore, this study evaluates the effect of partial cement substitution with fly ash (5%, 10%, and 15%) and the addition of Polyethylene Terephthalate (PET) waste (0.5% and 0.7%) on the mechanical properties of SCC with a target strength of f’c 30 MPa. The research employed laboratory experimental methods, including fresh concrete tests (slump flow, L-box, and V-funnel) and hardened concrete tests (compressive, tensile, and flexural strength) at 7 and 28 days. The results indicate that fly ash substitution enhances compressive strength, with the highest value of 49.59 MPa achieved at 5% fly ash at 28 days, exceeding normal concrete (34.73 MPa). The addition of PET tends to reduce compressive strength due to increased porosity; however, it significantly improves flexural strength, as the combination of 5% fly ash and 0.5% PET achieved 4.7 MPa compared to 2.9 MPa for normal concrete. Overall, the combination of fly ash and PET waste shows potential for application in structural elements requiring high flexural performance.

Human activities, from household to industrial operations, generate liquid waste that poses a threat to the environment. Before discharge, liquid waste should be treated to ensure it is safe for release into the environment. This study aims to evaluate the effectiveness of a hybrid ozonation-adsorption method with varying contact times. This study collected leachate samples from the Rajabasa Landfill and used fly ash from the Tarahan Coal-Fired Power Plant as the adsorbent. First, the study used contact times of 20, 40, 60, and 80 minutes for ozonation. Subsequently, the 80-minute sample proceeded to the adsorption stage and was ultimately tested against six parameters. The measured parameters included COD, TSS, TDS, turbidity, UV254, and DO. The results showed that the 80-minute ozonation process significantly reduced TSS, TDS, and DO levels. However, the ozonation process still left intermediate compounds, which were subsequently removed by adsorption. Ultimately, the combination of the two processes yields good results, particularly for COD and UV254. This aligns with the theory that ozonation breaks down complex compounds while the adsorbent absorbs residual pollutants. This hybrid process achieves a 45.47% reduction in COD and an 87.83% reduction in UV254.

The increasing demand for housing in tropical regions requires building materials that are fast to apply, environmentally friendly, and resilient to extreme climate conditions as well as disaster risks. Conventional interlocking bricks are often chosen for their ease of construction, yet they still face challenges such as moisture and early cracking. This study proposes the innovation of the Hybrid Living Green Brick, a combination of lightweight bricks made from rice husk ash and fly ash waste (FRCB) with a biological layer of cyanobacteria. FRCB improves compressive strength by approximately 30% with the addition of 5% rice husk ash, achieving 65 kg/cm², thereby meeting Class 50 requirements (≥50 kg/cm²) according to SNI-15-2094-2000. The incorporation of 3% cyanobacteria provides an additional though not significant strength improvement, while still within the Class 50 category. It also reduces brick weight by 4.3%, with further optimization potential through cyanobacteria integration, and lowers carbon emissions from the firing process. Cyanobacteria induce the formation of CaCO₃ layers that seal pores, reduce water absorption by an average of 10%, and provide self-healing properties for microcracks. Preliminary observations indicate that FRCB offers stable mechanical performance, while biological activity was observed on the 7th day with the formation of pale-white mineral layers continuing until the 28th day. This hybrid innovation shows potential to support sustainable and disaster-resilient tropical construction by combining the mechanical strength of waste-based materials with the biological durability of cyanobacteria against extreme climates. Despite challenges related to moisture control and production standardization, the Hybrid Living Green Brick concept opens new pathways for developing environmentally friendly construction materials that are more adaptive to disaster-prone tropical conditions.

In general, infrastructure development requires materials from nature and one of them is natural coarse aggregate of crushed stone. The rapid development of infrastructure in Indonesia has resulted in the depletion of the natural coarse aggregate. Therefore, other efforts are needed in terms of using coarse aggregate as a construction material. So in this study the aim is to make artificial coarse aggregate made from fly ash. The results showed that this artificial coarse aggregate met the requirements of the General Specifications of Bina Marga 2010 rev 3 as a construction material, namely for an abrasion value of 40% and water absorption of 3%. In this study, 5 types of comparisons were carried out, namely, 70:30%, 60:40%, 50:50%, 40:60%, 30:70 and for the type of composition comparison 70:30% (70% fly ash:30% cement). ) the abrasion value is still below 40%, and the amount of water absorption is below 3% so that this artificial coarse aggregate still meets the standard specifications of General Highways 2010 rev 3. Based on the price comparison that has been made between artificial coarse aggregate and natural coarse aggregate of crushed stone , shows a price disparity of Rp. 35,779 - Rp. 58,779. Thus, this artificial coarse aggregate is one solution that can be developed to reduce the environmental impact due to the presence of fly ash which is quite abundant in Indonesia.

Fly ash and bottom ash (FABA) are combustion residues from coal-fired power plants. Following the issuance of Government Regulation No. 22 of 2021, FABA is no longer classified as hazardous and toxic waste (B3). However, FABA must still be managed properly due to its potential to cause pollution through leachate generated if leaks occur in the FABA disposal area. This study evaluates the lining and drainage systems in the FABA disposal area at PT. PLN Nusantara Power UP Paiton to ensure that leachate does not contaminate surrounding groundwater. The research employs descriptive qualitative and quantitative methods, collecting secondary data to assess the structure and pollution control systems in the FABA disposal area at PT. PLN Nusantara Power UP Paiton. The data includes the disposal area structure and water quality from monitoring wells. Analysis results indicate that the FABA disposal area lining system operates effectively and in compliance with regulations, successfully containing leachate movement and preventing seepage. This is supported by pH, Fe, Hg, and turbidity levels in groundwater from monitoring wells remaining within safe limits. Additionally, the presence of a runoff pond helps contain surface runoff during heavy rain, keeping overflow water under control. Overall, the disposal area structure and leachate management system at PT. PLN Nusantara Power UP Paiton function well, but routine monitoring must continue to ensure no seepage occurs, preventing leachate from contaminating the surrounding environment as an early preventive measure to maintain environmental quality and regulatory compliance.

Beton sebagai material utama konstruksi sering mengalami panas hidrasi yang menyebabkan perbedaan suhu permukaan dengan suhu inti, akan berpotensi retak dini dan penurunan kuat tekan. Penelitian ini menganalisis potensi air es dan fly ash 10% substitusi semen untuk memperkecil suhu beton mutu 35 MPa dengan aditif tipe D (retarder) dan F (superplasticizer), serta pengaruhnya terhadap kuat tekan. Metode deskriptif menggunakan data sekunder mix design tiga variasi: non fly ash, fly ash 10% dan fly ash 10%+air es 10°C. Suhu beton segar diukur dengan thermogun/thermometer lalu kuat tekan uji silinder diameter 150x300 mm umur 7 hari dan 28 hari dengan total 18 benda uji. Hasil menunjukkan suhu beton segar non fly ash berada pada rentang normal, beton fly ash 10% turun 1-2°C (reaksi pozzolanik lambat yang mengurangi panas hidrasi dari C2S, C3S, dan C3A), beton fly ash 10% + air es turun 5-6°C. Kuat tekan 7 hari menunjukkan beton non fly ash 33,69 MPa, beton fly ash 10% 34,14 MPa, beton fly ash 10%+air es 34,73 MPa. Pada umur 28 hari menunjukkan beton non fly ash 39,73 MPa, beton fly ash 10% 39,80 MPa, dan beton fly ash 10%+air es 39,65 MPa – semua melebihi mutu rencana.

This study analyzes the potential use of cockle shell waste and coal fly ash as alternative raw materials in the production of composite brake pads. The high volume of industrial and fisheries waste, which has not been optimally utilized, encourages the exploration of environmentally friendly materials with adequate mechanical performance. The main focus of this research is the compressive strength of the produced brake pads, as this parameter is crucial for ensuring effective and safe braking performance. The method used includes the mixing and molding of composite materials with varying compositions of cockle shell and fly ash, followed by compressive strength testing according to standards. This study also takes into account the environmental impact of using waste as filler material, which is expected to reduce reliance on conventional materials and decrease waste that contaminates the environment. The results of the study are expected to provide empirical data on the potential of these two wastes as fillers in brake pad matrices and to identify the optimal formulation that provides the highest compressive strength. This study contributes to the development of sustainable braking materials and efforts to mitigate the environmental impact of waste, while also opening opportunities for the reuse of waste that has previously been poorly managed.

The durability of Self-Compacting Concrete (SCC) containing fly ash and Sika Viscocrete can be affected by exposure to seawater. This research investigates how seawater curing impacts the compressive strength of SCC modified with varying fly ash content and Sika Viscocrete admixture. The concrete mixtures were designed with 0% and 30% fly ash by cement weight and a constant 1% dosage of Sika Viscocrete. Compressive strength tests were conducted at 7, 14, and 28 days. The findings indicate that seawater curing has a notable effect on compressive strength, producing generally higher strength values than those cured in freshwater. Under freshwater conditions, strength increased steadily at 14 and 28 days, peaking at 54.1 MPa with 30% fly ash at 28 days. Conversely, the highest strength under seawater curing was achieved earlier, at 7 days, also with 30% fly ash, reaching 56.1 MPa. Overall, the optimum compressive strength was attained with a 30% fly ash mixture cured in seawater, suggesting this method enhances early-age strength in SCC.

This research is an experimental study on porous concrete and the use of fly ash as a binder for concrete to analyze the effect of compressive strength and porosity. The research method used in this study is the experimental method which is a research method used to find the effect of certain treatments on concrete. In this research, the concrete mix design uses a ratio of gravel and geopolymer paste as a binder, namely 4: 1 and uses a molarity ratio of 10M with differences in grading of coarse aggregate using sieves number 4, 1/2 ", and 3/8". The optimum compressive strength value was obtained in mix design 1 using sieve gradation no.4 which was 4.25 MPa at 28 days old. While the results of the highest porosity value were found in mix design 1 which was 7.15% at 28 days old

This research utilizes waste from PLTU Tanjung Jati B Jepara, namely FABA (Fly ash Bottom Ash) as an alternative to fine and coarse aggregate. From this research, the physical properties of faba aggregate can be seen from the results of the faba aggregate sieve analysis test, which obtained a fineness modulus value of 1.74, which is included in the medium aggregate type. The water content of fine aggregate (fly ash) obtained a value of 3.63% and coarse aggregate (bottom ash) obtained a value of 1.5%. The fine aggregate sludge content (fly ash) obtained a value of 0%. The fine aggregate organic substance (fly ash) acquires a reddish brown NaOH color, therefore it must be washed before being used as a concrete mixture. The face dry specific gravity of fine aggregate (fly ash) obtained a value of 2.63 gr/cm2 and coarse aggregate 2.52 gr/cm2. From the data that has been obtained, faba aggregate is considered to have physical properties that meet the requirements for fine aggregate and can be used as a substitute for sand. The results of the final compressive strength of faba concrete and normal concrete at the age of 7 days and 28 days showed that the compressive strength of normal concrete (control) was higher than that of faba concrete. The standard deviation values ​​at the ages of 7 and 28 days are included in perfect working conditions because they have a standard deviation value of less than 3 MPa. From the results of the concrete flexural strength test, only the control concrete was 1;1.5 with a flexural strength of 4.18 MPa, which is close to SNI 2847:2013, namely with a minimum flexural strength of fs = 4.4 MPa. Normal concrete has a higher flexural strength than faba concrete. Based on tests carried out with the planned mix design, the 1:1.5 variation obtained the highest results.

Coal is an organic mineral from ancient plant remains that settles and goes through physical or chemical processes over a period of up to millions of years. Coal is used as a source of steam-powered electrical energy through combustion which produces fly ash waste. fly ash contains various chemical materials such as SiO2; Al2O3; Fe2O3. The potential chemical content makes fly ash which can be used as an adsorbent for heavy metals and dyes by forming silica xerogel. To increase the silica oxide content in fly ash, a washing process is carried out with various solvents. Research on the adsorption of methylene blue dye using silica xerogel from fly ash with variations in contact time. The results showed that silica xerogel from fly ash was able to adsorb methylene blue dye at a contact time of 90 minutes. Adsorption kinetics follows a pseudo second order model with an R2 value that is better than pseudo first order. It can be seen that the R2 value respectively shows a linear regression of 0.703 for pseudo first order and 1 for pseudo second order.

Clay soils generally have low bearing capacity and are vulnerable to the water. Therfore, stabilization is necessary as an effort to increase the bearing capacity and improve the other parameters, one fo them by adding other materials such as fly ash and coral limestone powder as done in this research. The purpose of this research is to understand the effect of fly ash and coral limestone powder addition to the bearing capacity of clay soils after compaction process in term of CBR value by adding 15% fly ash and 0%, 10%, 20%, 30% coral limestone powder variations. The analysis results show that the original soil is an inorganic clay with 47,84% plasticity index. By adding fly ash and coral limestone powder variations decreases the plasticity index value to the lowest value 20,23%. The specific gravity increased on the 15% fly ash addition from 2,63 to 2,868 and decreased along with coral limestone powder addition to the lowest value 2,556. The maximum dry density decreased by adding 15% fly ash from 1,465 gr/cm3 on the original soil to 1,450 gr/cm3 and increased along with coral limestone powder addition to the highest value 1,522 gr/cm3. The optimum moisture content decreased along with the fly ash and coral limestone powder addition from 26,80% to 20,50%. The CBR value increased from the lowest value 0,47% to the highest value 15,29%.

Fly density is an indicator of environmental sanitation assessment. Fly density is influenced by waste management, the National Waste Management Information System (SIPSN) shows that waste generation in Jambi City reaches 159,688.01 tons/year. The aim of this research is to determine factors related to the level of fly density in Temporary Waste Storage Sites (TPSS) in Telanaipura District, Jambi City 2023. This research is a quantitative research with a cross sectional method research design. This research was conducted in the Telanaipura District community with a sample of 94 people. Data analysis was carried out using univariate and bivariate methods using correlation tests. The results of this study indicate that knowledge (p=0.027), action (p=0.029), monitoring (p=0.017), sorting (p=0.016), collection (p=0.027), and transportation (p=0.026) have relationship with the level of fly density, while attitude (p=0.245) had no relationship with the level of fly density. Knowledge, action, monitoring, sorting, collection and transportation are factors related to the level of fly density in temporary waste storage sites in Telanaipura District. It is hoped that the public will pay attention to managing household waste properly.

Water absorption test and compressive strength test were conducted to determine the quality standards of paving blocks. This research was conducted by using a mixture of fly ash, bottom ash and cement. The tests carried out in this study were water absorption test and compressive strength test using 3 compositions of 5%, 8% and 12%. In each composition using 3 samples for testing. Tests were carried out with a vulnerable time between 7 days, 14 days and 28 days. The highest water absorption results in the 8% composition with water absorption of 1.467%. The highest compressive strength results in the 8% composition with a compressive strength of 10.479 Mpa.

Concrete typically consists of coarse aggregate, fine aggregate, cement, and water. However, cement production generates significant carbon dioxide emissions nearly equivalent to the tons of cement produced. One alternative to conventional concrete, which replaces cement as a binder, is geopolymer concrete. Geopolymer concrete utilizes fly ash or other materials containing silica and alumina as the binder. Unlike cement, which forms a binder through hydration, geopolymer concrete uses a chemical reaction with alkali activators such as Na2SiO3 (sodium silicate) and NaOH (sodium hydroxide). This study investigates the toughness of geopolymer concrete using cylindrical specimens measuring 15 cm x 30 cm with varying Na2SiO3 to NaOH ratios of 1:0.5, 1:1, and 1:1.5, cured at room temperature for 28 days. The study results show that the highest toughness was achieved with a sodium silicate to sodium hydroxide ratio of 1.5, yielding 2.7394 x 105 J/m3. Meanwhile, the toughness values for sodium silicate to sodium hydroxide ratios of 0.5 and 1.0 were 2.3748 x 105 J/m3 and 2.5821 x 105 J/m3, respectively. Thus, increasing the sodium silicate to sodium hydroxide ratio from 0.5 to 1.5 at an activator content of 0.43 affects the toughness of geopolymer concrete.

Coal mining activities often result in acid mine drainage (AMD), which can cause environmental pollution if not properly managed. This study aims to evaluate the potential use of fly ash from the Stream Power Plant (PLTU) Tenggarong to mitigate the impacts of AMD, specifically targeting iron (Fe), manganese (Mn), and pH parameters. Acid Mine drainage is formed when sulfide minerals oxidize, producing acidic compounds that can harm the environment. This research focuses on analyzing the ability of fly ash to adsorb iron and manganese from AMD solutions, as well its capability to increase solution pH. Based on the conducted research, the optimum pH value was achieved when using 10 grams and 15 grams of fly ash in the adsorption process. The optimum concentration of iron (Fe) was attained using 10 grams to 15 grams of fly ash, while for manganese (Mn), it was achieved with 20 grams to 25 grams of fly ash. The adsorption process using 25 grams of fly ash showed the highest efficiency in reducing iron (Fe) concentration by 93.78 % and manganese (Mn) concentration by 75.47 %.

Utilization of fly ash which is part of the residue from burning coal for power plants (PLTU), where the combustion products have the same size as sand. Asphalt concrete is a type of construction pavement consisting of a mixture of asphalt and aggregate, either with or without added materials. This research aims to determine the characteristic values ​​of asphalt using fly ash as a substitute for sand in AC – WC asphalt concrete with mixed variations of 25%, 50% and 75%. From the research results, the AC-WC mixture used according to the standard, namely the condition of 5.5% asphalt content, obtained a stability value of 1580kg, a VFB value of 79.00%, a VMA value of 15.50%, a VIM value of 3.40%, a MQ value of 550kg/mm ​​, flow value 2.90mm and density value 2.35. Tests with mixture variations of 25%, 50% and 75% obtained a maximum stability value of 1706.5kg at a variation of 25%, a maximum flow value of 3.54mm at a variation of 75%, a maximum VIM value of 6.90% at a variation of 75%, a maximum VMA value 17.68% at 75% variation, maximum VFB value 84.89% at 25% variation, maximum density value 2.38 at 25% variation and MQ value 605.33kg/mm ​​at 25% variation. From the results of a study of the characteristics of asphalt using fly ash as a substitute for sand in AC-WC concrete asphalt with a variation of 50% which meets the requirements of the 2018 General Specifications Revision 2.    

The aim of this literature study is to conclude that the use of fly ash as a replacement material for most of the functions of cement in concrete mixes meets the standards for using concrete mixes as environmentally friendly building construction materials in the context of sustainable development, reducing the risk of the greenhouse effect caused by carbon dioxide. The conclusion is that Fly ash, as waste from burning coal for power plants, can be used as a substitute for most of the functions of Portland cement, so that the waste material becomes an economic value and an effort to save the environment. And the mechanism for using HVFA-SCC concrete provides a work productivity solution in the construction sector in reducing the use of labor more efficiently and economically, as well as reducing the use of a large proportion of cement in the concrete composition. Fly ash contains physical and chemical elements with an equivalent composition that is similar to Portland cement. The softness of the fly ash grains is beneficial for filling empty spaces, making the concrete denser and more compact. The equivalent physical and chemical properties mean that fly ash can replace Portland cement.