Coal Bottom Ash: History
View Latest Version
Please note this is an old version of this entry, which may differ significantly from the current revision.
Subjects: Engineering, Civil
Contributor:
Mohd Rasdan Ibrahim

Coal bottom ash (CBA) is physically similar to natural aggregates and resembles Portland cement (PC) when pulverized into finer particles.

  • coal bottom ash
  • waste material
  • recycle
  • construction industry
  • civil engineering

1. Introduction

The increasing trend in coal consumption will continue mainly due to the high demand for electricity. Coal is rapidly gaining favor as an energy source for generating electricity, after gas [1]. The 0.9% increase in world coal consumption in 2019 was driven by Asia (1.8%). The utilization of coal as a global source of electricity generation is expected to increase to 47% by 2030 [2][3].

The high demand for coal production has resulted in the generation of a higher amount of industrial waste. Fly ash makes up 70–80% of the total coal ash wastes, and the remaining 10–20% is bottom ash [2][4][5]. Of the millions of tons of coal ash waste generated annually, 100 million metric tons (Mt) is bottom ash, and the remainder is fly ash [6]. The World of Coal Ash (WOCA) estimated that coal thermal power plants generate 780 million metric tons of coal bottom ash (CBA), of which 66% is by Asian countries, followed by Europe and the United States [7]. China produces the highest amount of coal ash of 395 million metric tons (Mt), followed by the US (118 Mt), India (105 Mt), Europe (52.6 Mt), and Africa (31.1 Mt). The Middle East and other countries contributed a small amount to the global coal ash generation [8]. Of the 105 million metric tons of coal produced in India [8], about 35 million metric tons is coal bottom ash produced by the power plants that generate electricity [9].

The wastes produced in electricity generation are boiler slag, fly ash, clinker, and bottom ash [10][11]. The physical properties and the chemical composition of bottom ash and fly ash differ because fly ash is lighter than the bottom ash collected in a hopper after falling through the bottom furnace. The bottom ash could be wet or dry bottom ash, depending on the type of boiler.

The disposal of bottom ash landfills has raised a grave environmental concern [12][13]. The high composition of heavy metal in bottom ash, relative to fly ash, increases the risk of groundwater pollution [14][15]. One way to deal with the increasing amount of CBA generated and the scarcity of land is by recycling and reusing CBA [16].

2. Properties of Coal Bottom Ash

The specific properties of coal bottom ash are dependent on factors such as the coal source and type of coal. There are four types of coal: anthracite, bituminous, sub-bituminous, and lignite [17]. The type of coal is dependent on the types and amounts of carbon, the amount of heat energy the coal can produce, the level of carbon moisture, and other chemical elements [18]. Anthracite has the highest carbon content, followed by bituminous, sub-bituminous, and lignite. Generally, the types of coal used in energy generation are bituminous, sub-bituminous, and lignite. The geological formation of the coal determines its chemical composition; the CBA from the different types of coal have varying silica oxide (SiO 2), alumina oxide (Al 2O 3), and ferric oxide (Fe 2O 3) contents and characteristics that influence the research finding [18][19].

Researchers have investigated steel slag, coconut waste, recycled asphalt, recycled concrete, mining waste, glass, crumb rubber, palm oil shell, and palm oil clinker as natural aggregate replacement. Table 1 summarizes the physical properties of the wastes used as aggregate replacement in asphalt pavements and concrete production.

Table 1. The physical properties of the wastes used as aggregates in asphalt pavement and concrete production.

Waste Physical Property Parameters Used As  
Specific Gravity (No Unit) Water Absorption (%) Los Angeles Abrasion (%) Moisture Content (%) Fineness Modulus (%) Fine Coarse Reference
Steel slag 3.41 1.49 11.29       √ [20]
3.01 - 14.2       √ [21]
3.42 * 3.31 * - 1.56 * - √ √ [22]
3.58 ** 4.23 ** 2.8 **
3.67 1.4 - - -   √ [23]
Coconut waste 1.15 21 -   6.78   √ [24][25]
1.16 13.8 - - -   √ [26]
Recycled asphalt 2.68 0.20 22.2     √ √ [27]
2.55 0.23 20.25     √ √ [28]
Recycled concrete 2.41 * 4.80 * 18.7     √ √ [29]
2.42 ** 7.40 **
2.18 * 2.69 * 24     √ √ [30][31][32]
2.42 ** 4.28 **
2.35 8.01 - 9.1 - √ √ [33]
2.42–2.44 * 6.5–6.8 * - - - √ √ [34]
2.415 ** 9 **
2.53 3.04 - - -   √ [35]
2.44 5.65 - - 6.92   √ [36]
Mining waste 2.34 0.86 20.5       √ [37]
2.87 0.23 25.3     √ √ [38]
Glass 2.3 20–25 - - -   √ [39]
2.45 0.36 - - - √   [35]
Crumb rubber 1.15 - -     √   [40]
1.25 - -     √   [41]
Palm oil shell 1.37 12.47 - - 6.53   √ [42]
1.3 25 - - -   √ [43]
Palm oil clinker 2.08 - -     √   [44][45]
1.51 5.5 - 0.31 -   √ [46]
1.78 5.7 - 0.38 -   √ [47]
1.18 * 4.35 * - 0.28 *   √ √ [48]
2.15 ** 5.75 ** 0.11 **

* Coarse aggregate, ** fine aggregate.

The physical properties of the wastes used as aggregates in asphalt pavement and concrete production.

Asphalt construction requires a large amount of natural aggregates, namely 100% aggregates for the base and subbase courses, 95% for bituminous, and 87% for concrete pavements. The natural aggregates used to construct one kilometer of a surface course using a bituminous mixture could exceed 15,000 tons [6]. In recent years, natural aggregate replacement with CBA has reduced construction costs and minimized the need to harvest aggregates from natural resources.

3. Applications of Coal Bottom Ash

3.1. Pavement Construction

Prior studies on the utilization of coal ash waste in the construction industry focused more on fly ash than bottom ash. However, recent studies reported that bottom ash has some desired engineering properties that make it a feasible construction material. The minimum strength, stability, durability, and other specifications of the products incorporated with CBA must be complied with [49]. CBA has been used as an aggregate replacement, cement replacement, additive in bitumen, and filler in asphalt pavement. Table 2 summarizes the effect of CBA in pavement construction.
Table 2. Summary of the utilization of CBA in pavements.
References Function Effect on Pavement Performance
[50] Filler in SMA mixture
  • Reduced Marshall stability, resilient modulus, tensile strength, and fatigue properties of the pavements.
  • Improved moisture resistance.
[51] Filler replacement
  • Reduced pavement stability and rutting resistance.
  • Improved moisture resistance.
[52] Fine aggregate in HMA
  • Higher OBC with 10% CBA replacement. However, there was no significant difference with a higher percentage of CBA replacement.
  • No significant change in moisture susceptibility.
  • Improved fatigue resistance.
[53] Cement replacement in roller-compacted concrete pavement
  • Increased the water/cement ratio.
  • The RCCP mixtures containing higher amounts of coal waste ash had a lower strength.
  • Coal waste ash produced better mechanical properties when used in combination with limestone.
[54] Filler replacement in asphalt mixture
  • The high specific surface area of the bottom ash particles resulted in a higher percentage of asphalt binder and better mastic quality.
  • Lower CO2 emissions in the processing of bottom ash compared to a commercial filler.
[55] Filler replacement in HMA mixture
  • Improved stability, resilient modulus, moisture resistance, and tensile strength.
[56] An additive in cold recycled mixture
  • Enhanced stability, resilient modulus, and tensile strength.
[57] Fine aggregate in HMA
  • Enhanced stability and Cantabro index.
[58] Fine and coarse aggregate replacement
  • The difference in performance was not significant after a particular period of service. The varying properties of CBA from various coal sources influence the strength of the asphalt mixture.

3.2. Aggregate Replacement in Concrete Production

There has been an increase in literature on using bottom ash as an aggregate substitute in concrete production due to its porous texture and low particle densities. The literature reported the promising potential of bottom ash as an aggregate and cement substitute in concrete, particularly to enhance the concrete’s strength and microstructural properties. During the past several decades, there has been extensive research on using alternative materials in concrete manufacturing. The benefits of lightweight concrete are reduced weight, good thermal and sound insulation, durability, strength, low expansibility, ease of use in construction, and low cost [59].

3.3. Cement Replacement in Concrete Production

Besides using CBA as an aggregate replacement, researchers and technocrats investigated using CBA as cement replacement. The chemical properties of CBA are similar to cement as both are class F materials. The SiO2 content of CBA is greater than 25%, and the content of SiO2 + Al2O3 + Fe2O3 is higher than 70%, which meets the requirement for the recycling bottom ash as cement [60][61]. Moreover, replacing cement with CBA can reduce CO2 emissions and improved energy conservation.
Cement is the most widely used material in civil constructions. However, the high amount of carbon emitted in cement production has a harmful impact on the environment. An estimated 50% of the total CO2 emissions are from cement production. The production of each ton of cement releases 0.55 tons of CO2, and an additional 0.39 tons of CO2 is emitted during the baking and grinding processes, which are the key contributors to global warming [62].

3.4. Noise Barrier, Geotechnical Fill, Zeolite Composite, and Low-Cost Absorbent

Over the past four decades, extensive research has been conducted on noise barriers with different characteristics to protect the areas near roads, especially those with a high traffic volume [63]. Noise barrier wall, also known as the concrete wall, is one of the economic structures built to reduce noise pollution from transportation. Hannan et al. [60] investigated the production of concrete walls with varying CBA percentages that ranged from 0–100% fine aggregate replacement. The researchers reported that the values of fineness modulus of CBA were between 2.3 to 3.0, which is within the range as the fineness modulus of CBA was lower than the conventional fine aggregate specified in the BS 882:1992. The specific gravity of CBA was lower than the conventional fine aggregate due to the porous texture of CBA. The compressive strength of the concrete wall barriers did not increase linearly with higher CBA percentages, but increased with the concrete porosity, which is a good indicator for sound absorption structures. The sound absorption test to determine the acoustic performance showed that the walls containing 80–100% CBA were similar to the conventional wall and were class D absorbers; the remaining walls were class E absorbers. According to BS EN ISO 11,654:1997, the absorbers in class D absorb more than 30% of the sound, while class E absorbs between 15–25% of the sound [60].

This entry is adapted from the peer-reviewed paper 10.3390/su13148031

References

  1. Abubakar, A.U.; Baharudin, K.S. Tanjung Bin Coal Bottom Ash: From Waste to Concrete Material Tanjung Bin Coal Bottom Ash: From Waste to Concrete Material. Adv. Mater. Res. 2013.
  2. Yao, Z.T.; Ji, X.S.; Sarker, P.K.; Tang, J.H.; Ge, L.Q.; Xia, M.S.; Xi, Y.Q. Earth-Science Reviews A comprehensive review on the applications of coal fl y ash. Earth-Sci. Rev. 2015, 141, 105–121.
  3. Muthusamy, K.; Rasid, M.H.; Jokhio, G.A.; Mokhtar Albshir Budiea, A.; Hussin, M.W.; Mirza, J. Coal bottom ash as sand replacement in concrete: A review. Constr. Build. Mater. 2020, 236, 117507.
  4. Rafieizonooz, M.; Mirza, J.; Salim, M.R.; Hussin, M.W.; Khankhaje, E. Investigation of coal bottom ash and fly ash in concrete as replacement for sand and cement. Constr. Build. Mater. 2016, 116, 15–24.
  5. Singh, N.; Shehnazdeep; Bhardwaj, A. Reviewing the role of coal bottom ash as an alternative of cement. Constr. Build. Mater. 2020, 233, 117276.
  6. Ahmaruzzaman, M. A review on the utilization of fly ash. Prog. Energy Combust. Sci. 2010, 36, 327–363.
  7. Heidrich, C.; Feuerborn, H.; Weir, A. Coal Combustion Products: A Global Perspective. In Proceedings of the World of Coal Ash (WOCA) Conference, Lexington, KY, USA, 22–25 April 2013; Available online: http://www.mcilvainecompany.com/Decision_Tree/subscriber/Tree/DescriptionTextLinks/International%20flyash%20perspective.pdf (accessed on 1 June 2021).
  8. Sutcu, M.; Erdogmus, E.; Gencel, O.; Gholampour, A.; Atan, E.; Ozbakkaloglu, T. Recycling of bottom ash and fly ash wastes in eco-friendly clay brick production. J. Clean. Prod. 2019, 233, 753–764.
  9. Kumar, D.; Kumar, R.; Abbass, M. Study The Effect of Coal Bottom Ash on Partial Replacement of Fine Aggregate in Concrete With Sugarcane Molasses as an Admixture. Int. J. Sci. Res. Educ. 2016.
  10. Souad, E.M.E.A.; Moussaoui, R.; Monkade, M.; Lahlou, K.; Hasheminejad, N.; Margaritis, A.; Bergh, W. Van den Lime Treatment of Coal Bottom Ash for Use in Road Pavements: Application to EL Jadida Zone in Morocco. Materials 2019, 12, 1–15.
  11. Lokeshappa, B.; Kumar, A. Behaviour of Metals in Coal Fly Ash Ponds. Apcbee Procedia 2012, 1, 34–39.
  12. Rathnayake, M.; Julnipitawong, P.; Tangtermsirikul, S.; Toochinda, P. Utilization of coal fly ash and bottom ash as solid sorbents for sulfur dioxide reduction from coal fired power plant: Life cycle assessment and applications. J. Clean. Prod. 2018, 202, 934–945.
  13. Singh, M.; Siddique, R. Effect of coal bottom ash as partial replacement of sand on workability and strength properties of concrete. J. Clean. Prod. 2016, 112, 620–630.
  14. Menéndez, E.; Álvaro, A.M.; Hernández, M.T.; Parra, J.L. New methodology for assessing the environmental burden of cement mortars with partial replacement of coal bottom ash and fl y ash. J. Environ. Manag. 2014, 133, 275–283.
  15. Jang, J.G.; Ahn, Y.B.; Souri, H.; Lee, H.K. A novel eco-friendly porous concrete fabricated with coal ash and geopolymeric binder: Heavy metal leaching characteristics and compressive strength. Constr. Build. Mater. 2015, 79, 173–181.
  16. Singh, M.; Siddique, R. Compressive strength, drying shrinkage and chemical resistance of concrete incorporating coal bottom ash as partial or total replacement of sand. Constr. Build. Mater. 2014, 68, 39–48.
  17. Kim, R.G.; Li, D.; Jeon, C.H. Experimental investigation of ignition behavior for coal rank using a flat flame burner at a high heating rate. Exp. Therm. Fluid Sci. 2014, 54, 212–218.
  18. Gooi, S.; Mousa, A.A.; Kong, D. A critical review and gap analysis on the use of coal bottom ash as a substitute constituent in concrete. J. Clean. Prod. 2020, 268, 121752.
  19. Antoni; Klarens, K.; Indranata, M.; Al Jamali, L.; Hardjito, D. The use of bottom ash for replacing fine aggregate in concrete paving blocks. MATEC Web Conf. 2017, 138.
  20. Alinezhad, M.; Sahaf, A. Investigation of the fatigue characteristics of warm stone matrix asphalt (WSMA) containing electric arc furnace (EAF) steel slag as coarse aggregate and Sasobit as warm mix additive. Case Stud. Constr. Mater. 2019, 11, e00265.
  21. Ameli, A.; Hossein Pakshir, A.; Babagoli, R.; Norouzi, N.; Nasr, D.; Davoudinezhad, S. Experimental investigation of the influence of Nano TiO2 on rheological properties of binders and performance of stone matrix asphalt mixtures containing steel slag aggregate. Constr. Build. Mater. 2020, 265, 120750.
  22. Pang, B.; Zhou, Z.; Xu, H. Utilization of carbonated and granulated steel slag aggregate in concrete. Constr. Build. Mater. 2015, 84, 454–467.
  23. Wang, S.; Zhang, G.; Wang, B.; Wu, M. Mechanical strengths and durability properties of pervious concretes with blended steel slag and natural aggregate. J. Clean. Prod. 2020, 271, 122590.
  24. Mathew, S.P.; Nadir, Y.; Arif, M.M. Experimental study of thermal properties of concrete with partial replacement of coarse aggregate by coconut shell. Mater. Today Proc. 2020, 27, 415–420.
  25. Nadir, Y.; Sujatha, A. Durability Properties of Coconut Shell Aggregate Concrete. KSCE J. Civ. Eng. 2018, 22, 1920–1926.
  26. Kanojia, A.; Jain, S.K. Performance of coconut shell as coarse aggregate in concrete. Constr. Build. Mater. 2017, 140, 150–156.
  27. Devulapalli, L.; Kothandaraman, S.; Sarang, G. Evaluation of rejuvenator’s effectiveness on the reclaimed asphalt pavement incorporated stone matrix asphalt mixtures. Constr. Build. Mater. 2019, 224, 909–919.
  28. Devulapalli, L.; Kothandaraman, S.; Sarang, G. Effect of rejuvenating agents on stone matrix asphalt mixtures incorporating RAP. Constr. Build. Mater. 2020, 254, 119298.
  29. Nwakaire, C.M.; Yap, S.P.; Yuen, C.W.; Onn, C.C.; Koting, S.; Babalghaith, A.M. Laboratory study on recycled concrete aggregate based asphalt mixtures for sustainable flexible pavement surfacing. J. Clean. Prod. 2020, 262, 121462.
  30. Pourtahmasb, M.S.; Karim, M.R. Performance Evaluation of Stone Mastic Asphalt and Hot Mix. Adv. Mater. Sci. Eng. 2014, 2014, 1–12.
  31. Pourtahmasb, M.S.; Karim, M.R.; Shamshirband, S. Resilient modulus prediction of asphalt mixtures containing Recycled Concrete Aggregate using an adaptive neuro-fuzzy methodology. Constr. Build. Mater. 2015, 82, 257–263.
  32. Pourtahmasb, M.S.; Karim, M.R. Utilization of Recycled Concrete Aggregates in Stone Mastic Asphalt Mixtures. Adv. Mater. Sci. Eng. 2014, 2014.
  33. Bui, N.K.; Satomi, T.; Takahashi, H. Improvement of mechanical properties of recycled aggregate concrete basing on a new combination method between recycled aggregate and natural aggregate. Constr. Build. Mater. 2017, 148, 376–385.
  34. Omrane, M.; Kenai, S.; Kadri, E.H.; Aït-Mokhtar, A. Performance and durability of self compacting concrete using recycled concrete aggregates and natural pozzolan. J. Clean. Prod. 2017, 165, 415–430.
  35. Lu, J.X.; Yan, X.; He, P.; Poon, C.S. Sustainable design of pervious concrete using waste glass and recycled concrete aggregate. J. Clean. Prod. 2019, 234, 1102–1112.
  36. Singh, N.; Mithulraj, M.; Arya, S. Utilization of coal bottom ash in recycled concrete aggregates based self compacting concrete blended with metakaolin. Resour. Conserv. Recycl. 2019, 144, 240–251.
  37. Huang, Q.; Qian, Z.; Hu, J.; Zheng, D. Evaluation of Stone Mastic Asphalt Containing Ceramic Waste Aggregate for Cooling Asphalt Pavement. Materials 2020, 13, 2964.
  38. Gautam, P.K.; Kalla, P.; Nagar, R.; Agrawal, R.; Jethoo, A.S. Laboratory investigations on hot mix asphalt containing mining waste as aggregates. Constr. Build. Mater. 2018, 168, 143–152.
  39. Adhikary, S.K.; Rudzionis, Z. Influence of expanded glass aggregate size, aerogel and binding materials volume on the properties of lightweight concrete. Mater. Today Proc. 2020, 32, 712–718.
  40. Wang, X.; Fan, Z.; Li, L.; Wang, H.; Huang, M. Durability evaluation study for crumb rubber-asphalt pavement. Appl. Sci. 2019, 9, 3434.
  41. Malarvizhi, G.; Senthil, N.; Kamaraj, C. A Study on Recycling Of Crumb Rubber and Low Density Polyethylene Blend on Stone Matrix Asphalt. Int. J. Sci. Res. Publ. 2012, 2, 1–16.
  42. Ahmad Zawawi, M.N.A.; Muthusamy, K.; Abdul Majeed, A.P.P.; Muazu Musa, R.; Mokhtar Albshir Budiea, A. Mechanical properties of oil palm waste lightweight aggregate concrete with fly ash as fine aggregate replacement. J. Build. Eng. 2020, 27, 100924.
  43. Mo, K.H.; Alengaram, U.J.; Jumaat, M.Z.; Liu, M.Y.J.; Lim, J. Assessing some durability properties of sustainable lightweight oil palm shell concrete incorporating slag and manufactured sand. J. Clean. Prod. 2016, 112, 763–770.
  44. Mohammed Babalghaith, A.; Koting, S.; Ramli Sulong, N.H.; Karim, M.R.; Mohammed AlMashjary, B. Performance evaluation of stone mastic asphalt (SMA) mixtures with palm oil clinker (POC) as fine aggregate replacement. Constr. Build. Mater. 2020, 262, 120546.
  45. Babalghaith, A.M.; Koting, S.; Ramli Sulong, N.H.; Karim, M.R.; Mohammed, S.A.; Ibrahim, M.R. Effect of palm oil clinker (POC) aggregate on the mechanical properties of stone mastic asphalt (SMA) mixtures. Sustainability 2020, 12, 2716.
  46. Nayaka, R.R.; Alengaram, U.J.; Jumaat, M.Z.; Yusoff, S.B.; Ganasan, R. Performance evaluation of masonry grout containing high volume of palm oil industry by-products. J. Clean. Prod. 2019, 220, 1202–1214.
  47. Hamada, H.M.; Yahaya, F.M.; Muthusamy, K.; Jokhio, G.A.; Humada, A.M. Fresh and hardened properties of palm oil clinker lightweight aggregate concrete incorporating Nano-palm oil fuel ash. Constr. Build. Mater. 2019, 214, 344–354.
  48. Abutaha, F.; Razak, H.A.; Ibrahim, H.A.; Ghayeb, H.H. Adopting particle-packing method to develop high strength palm oil clinker concrete. Resour. Conserv. Recycl. 2018, 131, 247–258.
  49. Gautam, P.K.; Kalla, P.; Jethoo, A.S.; Agrawal, R.; Singh, H. Sustainable use of waste in flexible pavement: A review. Constr. Build. Mater. 2018, 180, 239–253.
  50. Ameli, A.; Babagoli, R.; Norouzi, N.; Jalali, F.; Poorheydari Mamaghani, F. Laboratory evaluation of the effect of coal waste ash (CWA) and rice husk ash (RHA) on performance of asphalt mastics and Stone matrix asphalt (SMA) mixture. Constr. Build. Mater. 2020, 236, 117557.
  51. Xu, P.; Chen, Z.; Cai, J.; Pei, J.; Gao, J.; Zhang, J.; Zhang, J. The effect of retreated coal wastes as filler on the performance of asphalt mastics and mixtures. Constr. Build. Mater. 2019, 203, 9–17.
  52. Yoo, B.S.; Park, D.W.; Vo, H.V. Evaluation of Asphalt Mixture Containing Coal Ash. Transp. Res. Procedia 2016, 14, 797–803.
  53. Hesami, S.; Modarres, A.; Soltaninejad, M.; Madani, H. Mechanical properties of roller compacted concrete pavement containing coal waste and limestone powder as partial replacements of cement. Constr. Build. Mater. 2016, 111, 625–636.
  54. Suárez-Macías, J.; Terrones-Saeta, J.M.; Iglesias-Godino, F.J.; Corpas-Iglesias, F.A. Evaluation of physical, chemical, and environmental properties of biomass bottom ash for use as a filler in bituminous mixtures. Sustainability 2021, 13, 4119.
  55. Modarres, A.; Rahmanzadeh, M. Application of coal waste powder as filler in hot mix asphalt. Constr. Build. Mater. 2014, 66, 476–483.
  56. Modarres, A.; Ayar, P. Coal waste application in recycled asphalt mixtures with bitumen emulsion. J. Clean. Prod. 2014, 83, 263–272.
  57. Colonna, P.; Berloco, N.; Ranieri, V.; Shuler, S.T. Application of Bottom Ash for Pavement Binder Course. Procedia Soc. Behav. Sci. 2012, 53, 961–971.
  58. Ksaibati, K.; Stephen, J. Utilization of Bottom Ash in Asphalt Mixes; No. MCP Report No. 99–104A; Department of Civil and Architectural Engineering, University of Wyoming: Laramie, WY, USA, 1999; Available online: https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.593.9395&rep=rep1&type=pdf (accessed on 1 June 2021).
  59. Aydin, E. Novel coal bottom ash waste composites for sustainable construction. Constr. Build. Mater. 2016, 124, 582–588.
  60. Hannan, N.I.R.R.; Shaidan, S.; Ali, N.; Bunnori, N.M.; Mohd Zuki, S.S.; Wan Ibrahim, M.H. Acoustic and non-acoustic performance of coal bottom ash concrete as sound absorber for wall concrete. Case Stud. Constr. Mater. 2020, e00399.
  61. García Arenas, C.; Marrero, M.; Leiva, C.; Solís-Guzmán, J.; Vilches Arenas, L.F. High fire resistance in blocks containing coal combustion fly ashes and bottom ash. Waste Manag. 2011, 31, 1783–1789.
  62. Singh, N.; Mithulraj, M.; Arya, S. Influence of coal bottom ash as fine aggregates replacement on various properties of concretes: A review. Resour. Conserv. Recycl. 2018, 138, 257–271.
  63. Lacasta, A.M.; Penaranda, A.; Cantalapiedra, I.R.; Auguet, C.; Bures, S.; Urrestarazu, M. Acoustic evaluation of modular greenery noise barriers. Urban For. Urban Green. 2016, 20, 172–179.
More
© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license; additional terms may apply. By using this site, you agree to the Terms and Conditions and Privacy Policy.
This entry is offline, you can click here to edit this entry!
Video Production Service
Feedback