Effects of Red Mud Addition in the Microstructure, Durability and Mechanical Performance of Cement Mortars

Ortega, José Marcos; Cabeza, M.; Tenza-Abril, Antonio José; Real-Herráiz, Teresa; Climent, M.Á.; Sánchez, Isidro

doi:10.3390/app9050984

Cited by 37 publications

(16 citation statements)

References 52 publications

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“…In particular, the strength degradation of LRM20 at ages of 1 and 3 d was noticeable, which agrees with the result that the accumulated heat of hydration of LRM20 was relatively low, as shown in Figure 4. The negative effects of LRM on the initial hydration also appear to have affected the compressive strength at the age of 28 d. In previous studies, the use of red mud was limited to 10% or less for the construction industry because red mud does not undergo pozzolanic reactions [1,20,21].…”

Section: Compressive Strengthmentioning

confidence: 99%

Effects of Adding Neutralized Red Mud on the Hydration Properties of Cement Paste

Kang

Hye-Ju

Lee³

2020

Materials

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Red mud is a highly alkaline waste by-product of the aluminum industry. Although recycling of red mud is being actively researched, a feasible technological solution has not been found yet. In this study, we propose that neutralization of red mud alkalinity could assist in its use as a construction material. Neutralized red mud (LRM + S; pH 6–8) was prepared by adding sulfuric acid to liquefied red mud (LRM; pH 10–12). After adding LRM and LRM + S to cement paste, the heat of hydration, compressive strength, and hydration products were examined. The experiments revealed that the calorific value of the cement paste with LRM was low, and its peak was delayed, when compared with that of plain cement paste (referred to as Plain), whereas the calorific value of the cement paste with LRM + S was similar to that of Plain. At the age of 28 d, the compressive strength of the cement paste with 10% LRM + S was 99% whereas that with 20% LRM was only 55% of the strength of Plain. Thus, our results help to resolve the issue of strength degradation of cementitious materials observed upon the addition of red mud and enable its reuse as a construction material.

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Section: Compressive Strengthmentioning

confidence: 99%

Effects of Adding Neutralized Red Mud on the Hydration Properties of Cement Paste

Kang

Hye-Ju

Lee³

2020

Materials

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“…The delay in the initial hydration due to the use of LRM without neutralization resulted in the low compressive strength after 28 days of aging. According to previous studies, RM content of 10% or less should be used in the construction industry because of its slower pozzolanic reaction than that of cement [ 21 , 22 , 23 ]. However, if LRM is neutralized, a higher ratio can be considered.…”

Section: Resultsmentioning

confidence: 99%

Hydration Properties of Cement with Liquefied Red Mud Neutralized by Nitric Acid

Kang

Hye-Ju

Lee³

2021

Materials

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An increasing amount of red mud (RM) is being generated globally due to the growth in aluminum production. To avoid RM pollution, low-cost methods for effectively recycling RM are being investigated. We propose a method for recycling RM as a construction material. Liquefied RM (LRM) was neutralized by nitric acid and added to cement paste, and the hydration heat, compressive strength, and hydration products were investigated. The cement paste with neutralized LRM had a higher compressive strength than that of plain cement paste and cement paste with LRM without neutralization at 1 day of aging; this indicates that nitric acid neutralization increases the early-age strength. Furthermore, the cement paste with 10% neutralized LRM showed 28 days-compressive strength and hydration heating curves similar to the plain mixture, indicating the positive impact of LRM neutralization on the strength. It was noted that a greater quantity of portlandite was produced earlier in cement paste with neutralized LRM than in that without. Therefore, the proposed method of using RM as a concrete additive has the potential to reduce the cost and environmental impact of both construction materials and RM waste management.

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“…The disposal of large quantities of red mud is very difficult and it leads to land, air and water pollution [11]. Because it has high alkaline nature and it contains many hazardous substances like metals and radioactive elements [12][13][14]. In the alumina production, one ton of alumina produces 1-1.5 tonnes of red mud [15].…”

Section: Introductionmentioning

confidence: 99%

“…The bauxite ore and refining process can influence the amount of red mud comes as a wastage. Many studies are done to use red mud in several industrial products such as ceramic tiles, brick manufacturing, cement production, land reclamation and others [10][11][12][13][14][15]. Also, red mud used in the treatment of waste water and exhaust gas as an adsorbent [15][16][17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

A State of the Art on Red Mud as a Substitutional Cementitious Material

Venkatesh¹,

Madduru²,

Nerella³

2019

ACSM

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Red mud is a highly alkaline solid waste produced from the alumina refinery plants. Every year more than 300 million tons of red mud is producing throughout world. Disposal of a large quantity of red mud is very expensive and it creates contamination of neighbor lands, air and water bodies. Using red mud as a sustainable cementitious material in concrete is highly appreciable, because concrete is a second largest using material after water. Moreover, reduce the negative effect on environment due to red mud disposal as well as cement industries. The present paper conducted a critical review on bayer process of red mud, physical and chemical properties of red mud. And also workability, mechanical, durability and microstructure characterization of red mud when used in concrete as sustainable cementitious material. In the red mud iron oxide and alumina oxide are presented abundantly. Red mud accelerates the heat of hydration in concrete and it leads to strength enhancement in early ages. Increases the quantity of red mud in concrete reduces the workability but increases the strength of concrete. However, the chemical composition of red mud and its particle size helps to improve the durability property of concrete. Red mud offers more capable to arrest the chloride ions and other ions diffusion into concrete. Red mud minimizes the micro cracks and voids present in concrete by its particles size as well as bonding nature with other materials up to certain dosage of red mud used in concrete.

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Effects of Red Mud Addition in the Microstructure, Durability and Mechanical Performance of Cement Mortars

Cited by 37 publications

References 52 publications

Effects of Adding Neutralized Red Mud on the Hydration Properties of Cement Paste

Effects of Adding Neutralized Red Mud on the Hydration Properties of Cement Paste

Hydration Properties of Cement with Liquefied Red Mud Neutralized by Nitric Acid

A State of the Art on Red Mud as a Substitutional Cementitious Material

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