Evaluation of Portland pozzolan blended cements containing diatomaceous earth

Abrão, P. C. R. A.; Cardoso, F. A.; John, Vanderley M.

doi:10.1590/0366-6913201965s12596

Cited by 13 publications

(8 citation statements)

References 22 publications

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“…The waste showed a significantly higher value, which can increase its reactivity as a pozzolanic material owing to the increase in the contact area. The specific surface area of the residue was consistent with previously reported values for other SCMs such as diatomaceous earth (4.30 m 2 /g) [52] and limestone fines (2.97 m 2 /g) [50]. Fig.…”

Section: Resultssupporting

confidence: 91%

Evaluation of the use of silica-alumina refractory waste as a supplementary cementitious material

et al. 2021

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The use of supplementary cementitious materials (SMCs) is one of the three essential factors for the sustainability of the cement industry. To reduce CO 2 emissions, several studies have introduced new methods for the utilization of industrial wastes such as the addition into cementitious materials. The objectives of this study were to chemically and physically characterize refractory ceramic industry waste and determine its viability as an SMC. The pozzolanic characteristics or SMC characteristics of the refractory waste were investigated using standard tests. The results revealed that the refractory waste was mainly composed of Al 2 O 3 and SiO 2 . The mineralogical analysis revealed that the mullite was the major phase of the waste, followed by small amounts of cristobalite and quartz phases. The results of the modified Chapelle test and pozzolanic activity index with lime after 7 days indicated that the waste did not meet the minimum pozzolanicity required by the standard. However, the waste improved the mechanical resistance of the cement specimens containing the waste after 28 days compared with the reference sample, indicating the promising potential of the material for this application. This result indicated that the refractory waste shows a filler type effect, and thus, can be employed as an SCM.

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Section: Resultssupporting

confidence: 91%

Evaluation of the use of silica-alumina refractory waste as a supplementary cementitious material

et al. 2021

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“…There is currently no other valid and known industrial technology to significantly reduce carbon dioxide emissions from Portland cement. Therefore, researchers and industrials have begun to consider environmental compatibility when selecting construction materials and have been developing strategies to reduce this environmental impact generated by the cement industry [4]. One of these strategies is the substitution of clinker or cement by supplementary cementitious materials (SCMs).…”

Section: Introductionmentioning

confidence: 99%

Study of chemical and thermal activations of zeolite-lime blend

et al. 2021

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The advantages of using zeolites are lower costs and better durability, but it requires longer setting time and slower strength development. Chemical and thermal methods have been developed to overcome these disadvantages and to enhance the reactivity of natural zeolite. This paper addressed through a parametric experimental pozzolanic reactivity, the strength and setting time by varying the cure temperature and the amount and type of chemical activators. To this end, several mixtures of natural zeolite-lime pastes were made with two concentrations of chemical activators including 4% and 8% of NaOH, NaCl, and CaSO 4 .2H 2 O. The produced pastes were cured at 20, 40, and 80 °C. The blends were also analyzed by X-ray diffraction and infrared spectroscopy. The results showed that curing at high temperatures accelerated the pozzolanic reactivity and increased the compressive strength. The use of CaSO 4 .2H 2 O led to an increase in the consumption of Ca(OH) 2 and strength. Adding NaCl improved slightly the compressive strength at high curing temperatures. The addition of 8% NaOH at 40 °C significantly improved reactivity and strength. Setting time was accelerated by adding chemical activators to the blends. The raw zeolite had good pozzolanic activity, but the addition of CaSO 4 .2H 2 O enhanced it.

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“…Industrial waste ashes : FA [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ], coal bottom ash [ 28 ], industrials slags [ 3 , 20 , 29 , 30 , 31 , 32 , 33 , 34 ], silica fume [ 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ], artificial pozzolans (calcined clays [ 34 , 43 , 44 , 45 ], ceramic residues [ 46 , 47 ], sedimentary rocks containing clay minerals and burned bauxites [ 48 , 49 , 50 ]), natural pozzolans (volcanic tuffs/zeolites [ 51 , 52 ], siliceous such as opal and diatomaceous earth [ 53 , 54 , 55 , 56 , 57 ], and volcanic glasses such as volcanic ashes [ 58 , 59 , 60 , 61 ,…”

Section: Introductionmentioning

confidence: 99%

Incorporation of Alkali-Activated Municipal Solid Waste Incinerator Bottom Ash in Mortar and Concrete: A Critical Review

Kurda

2020

Materials

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In the light of one of the most common waste management issues in urban areas, namely the elimination of municipal solid waste (MSW; about 486 kg of the waste per capita were generated in the EU in 2017), this study discusses one technique as an outlet in the construction industry for the by-product of the waste’s incineration in energy recovery facilities (i.e., MSW incinerator bottom ash—MIBA). There have been some investigations on the use of MIBA as partial replacement of cement to be used in cementitious composites, such as concrete and mortars. However, the waste’s incorporation ratio is limited since further products of hydration may not be produced after a given replacement level and can lead to an unsustainable decline in performance. In order to maximize the incorporation of MIBA, some research studies have been conducted on the alkali activation of the waste as precursor. Thus, this study presents an extensive literature review of the most relevant investigations on the matter to understand the material’s applicability in construction. It analyses the performance of the alkali-activated MIBA as paste, mortar, and concrete from different perspectives. This literature review was made using search engines of several databases. In each database, the same search options were repeated using combinations of various representative keywords. Furthermore, several boundaries were made to find the most relevant studies for further inspection. The main findings of this review have shown that the chemical composition and reactivity of MIBA vary considerably, which may compromise performance comparison, standardization and commercialization. There are several factors that affect the performance of the material that need to be considered, e.g., type and content of precursor, alkaline activator, curing temperature and time, liquid to solid ratio, among others. MIBA-based alkali-activated materials (AAM) can be produced with a very wide range of compressive strength (0.3–160 MPa). The main factor affecting the performance of this precursor is the existence of metallic aluminum (Al), which leads to damaging expansive reactions and an increase in porosity due to hydrogen gas generation stemming from the reaction with the alkaline activator. Several approaches have been proposed to eliminate this issue. The most effective solution was found to be the removal of Al by means of eddy current electromagnetic separation.

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Evaluation of Portland pozzolan blended cements containing diatomaceous earth

Cited by 13 publications

References 22 publications

Evaluation of the use of silica-alumina refractory waste as a supplementary cementitious material

Evaluation of the use of silica-alumina refractory waste as a supplementary cementitious material

Study of chemical and thermal activations of zeolite-lime blend

Incorporation of Alkali-Activated Municipal Solid Waste Incinerator Bottom Ash in Mortar and Concrete: A Critical Review

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