Quantification of the cement paste and phase’s association in fine recycled aggregates by SEM-based image analysis

Ulsen, Carina; Contessotto, Renato; Macedo, Rafael dos Santos; Kahn, Henrique

doi:10.1016/j.conbuildmat.2021.126206

Cited by 12 publications

(3 citation statements)

References 22 publications

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“…The study also looks at the connection between mineral composition and chemical analysis, finding that products with higher densities have more carbonates and less cement paste. Improving the quality of recycled aggregate is the goal of this study [44]. Zeolite-poor rock and sawdust are being explored as eco-friendly alternatives for clay bricks.…”

Section: Fig1 X-ray Fluorescence and Rietveld Quantitative Phase Anal...mentioning

confidence: 99%

Microstructural Analysis of Stabilized Rammed Earth Using XRD And SEM Methods

Fraz

2024

IJSREM

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The microstructure analysis of stabilized rammed earth (SRE) is crucial for understanding its mechanical properties, durability, and long-term performance. This literature review paper investigates the application of X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) in analyzing the microstructural characteristics of SRE. XRD is employed to identify the crystalline phases present in the material, providing insights into the mineralogical composition and the effects of stabilization agents. SEM offers high-resolution images that reveal the surface morphology, particle distribution, and bonding mechanisms within the stabilized matrix. By synthesizing recent studies, this review highlights the advancements in microstructural analysis techniques and their implications for the optimization of SRE in construction. The findings from XRD and SEM analyses are integrated to present a comprehensive understanding of the microstructure-property relationships in SRE. The literature suggests that stabilization methods, such as the addition of cement, lime, or other additives, significantly influence the crystallinity, particle interlocking, and pore structure of the rammed earth. This review discusses the correlation between microstructural features observed through XRD and SEM and the resulting mechanical properties, such as compressive strength and durability. The paper concludes by identifying gaps in the current research and proposing directions for future studies, emphasizing the need for standardized testing protocols and the exploration of novel stabilization materials to enhance the performance of SRE. Keywords: X-Ray Diffraction, Scanning Electron Microscopy, Energy Dispersive X-Ray Analysis

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Section: Fig1 X-ray Fluorescence and Rietveld Quantitative Phase Anal...mentioning

confidence: 99%

Microstructural Analysis of Stabilized Rammed Earth Using XRD And SEM Methods

Fraz

2024

IJSREM

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“…Indeed, by comparing the chemical compositions of CDWs from the literature [11][12][13][14][15][16][17][18][19][20], a huge compositional variability in the CDWs from different areas is observed. However, in some cases, a compositional affinity has been observed between CDW samples from the same area: in fact, two samples investigated by Abudureheman et al, 2021 [11] and Volpintesta et al, 2023 [19] showed similar CaO contents, despite being sampled years apart and at different recycling centres.…”

Section: Introductionmentioning

confidence: 99%

Compositional Differences in Construction and Demolition Wastes (CDWs) for Geopolymer Mortars: A Comparative Study Using Different Precursors and Alkaline Reagents

Volpintesta,

Finocchiaro,

Barone

et al. 2024

Minerals

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In the view of the recycling and upscaling processes of waste materials, three different precursors, namely metakaolin, fly ash and volcanic ash, were mixed with Na- or K-silicate to produce binders aimed for the synthesis of geopolymer mortars based on construction and demolition wastes (CDWs). These later, used as aggregates in amount of 50 wt.%, were sampled in two geologically different Italian areas. A comparative study was carried out through a multidisciplinary approach using mineralogical–chemical analyses and physical–mechanical tests for the characterization of six binders and twelve mortars. The aim was to verify the effects of CDW interactions on binders as well as the extent of their compositional influences on the final properties. The chemical and mineralogical results evidenced strong compositional differences among the CDWs, differently influencing the physical–mechanical performances (i.e., compressive strength, density, water absorption and porosity) of the mortar samples. Regardless of the types of precursors and CDWs used, a better influence of K-silicate than sodium on the synthetised samples was observed. Furthermore, the higher versatility of metakaolin mortars with any type of CDW used was noted. Contrary, fly ash and volcanic ash mortars showed better properties with CDWs based on their high silica content and volcanic minerals. The study highlighted the critical roles of the CDW composition and precursor selection in mortar production. It confirmed that CDWs can be recycled for geopolymeric synthesis through proper characterisation and binder selection. Optimising these parameters allows for the successful integration of CDWs into geopolymeric materials. This process supports the advancement of a circular economy in the construction industry.

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“…The image analysis method [26] and the linear traverse method [27,28] are suitable for the quantification of residual mortar in coarse RCA. The X-ray SEM-based image analysis developed by Ulsen et al [29] is too long to perform as a statistical approach is needed to obtain reliable results. The deionized water dissolution has the carbonation contamination problem.…”

Section: Introductionmentioning

confidence: 99%

Quantification of the Hardened Cement Paste Content in Fine Recycled Concrete Aggregates by Means of Salicylic Acid Dissolution

et al. 2022

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Adherent hardened cement paste attached to recycled concrete aggregates (RCA) generally presents a higher porosity than natural aggregates, which induces a lower porosity in the properties of RCA. The characterization of the adherent hardened cement paste content (HCPC) in the fine RCA would promote better applications of RCA in concrete, but the determination of HCPC in fine RCA is not well established. A simple method based on salicylic acid dissolution was specifically developed to quantify the HCPC in RCA, especially for RCA containing limestone aggregates. The results demonstrated that the soluble fraction in salicylic acid (SFSA) was equal to the HCPC for white cement and slightly lower for grey Portland cement, which was also confirmed by a theoretical approach using modelling the hydration of cement paste with the chemical equations and the stoichiometric ratios. The physical and mechanical properties of RCA (e.g., water absorption) were strongly correlated to the SFSA. For industrial RCA, SFSA did not give the exact value of HCPC, but it was sufficient to correlate HCPC with the other properties of RCA. The water absorption could be estimated with good accuracy for very fine RCA (laboratory-manufactured RCA or industrial RCA) by extrapolating the relationship between water absorption and HCPC, which is very important for concrete formulation.

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Quantification of the cement paste and phase’s association in fine recycled aggregates by SEM-based image analysis

Cited by 12 publications

References 22 publications

Microstructural Analysis of Stabilized Rammed Earth Using XRD And SEM Methods

Microstructural Analysis of Stabilized Rammed Earth Using XRD And SEM Methods

Compositional Differences in Construction and Demolition Wastes (CDWs) for Geopolymer Mortars: A Comparative Study Using Different Precursors and Alkaline Reagents

Quantification of the Hardened Cement Paste Content in Fine Recycled Concrete Aggregates by Means of Salicylic Acid Dissolution

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