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1

Sustainable deployment of crushed concrete aggregates strengthened with cement and sand

Sharma V., Kumar A., Kaur A.

Archives of Materials Science and Engineering

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2022

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Vol. 113, nr 1

19--34

EN

Purpose: Paper assessed the feasibility of crushed concrete aggregates (CCA), a subsidiary of construction and demolition (C&D) waste, blended with cement and sand to form a composite for civil engineering field applications. Design/methodology/approach: The compaction and strength characteristics of CCA were observed by conducting Proctor compaction and California Bearing Ratio (CBR) tests. Different proportions of CCA, sand and cement were used. Moreover, the effect of curing period (0, 4, 7, 14 and 28 days) was also studied. In addition, regression analyses were performed to develop empirical expressions to predict the compaction and strength characteristics of the CCA composite. Findings: Increasing the CCA content up to 50% increases the maximum dry unit weight (MDUW) and decreases the optimum moisture content (OMC). However, on further increasing its content the MDUW decreases and OMC increases. Percent increase in the CBR value can go up to 412% if the CCA content is increased up to 50%. However, the percent reduction in CBR of about 20% can take place if 100% CCA content is used. Moreover, multiple regression shows that the experimental results are in good agreement with the predicted values. Research limitations/implications: The results obtained are purely dependent on the type of material. However, they are in favour of the used material as a probable option for road sub-base layer, and also for reducing burden on available natural resources. Therefore, it is recommended to conduct some initial tests to confirm the feasibility of the material. Practical implications: The proposed study will guide the design Engineers to choose CCA as one of the potential materials for road construction. Originality/value: It was observed that there is a need to maximize the utilization of C&D waste without making any compromise with its mechanical properties. So keeping that in view, the present study was conducted.

2

Nanoadsorbents for the preconcentration of some toxic substances : a minireview

Kaur A., Saini S. S.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 2

22-35

EN

The development of new sorbents and their application in preconcentration methods for determination of trace analytes is subject of great interest. Sample pretreatment methods, such as separation / preconcentration prior to the determination of metal ions have developed rapidly due to the increasing need for accurate and precise measurements at extremely low levels of ions in diverse matrices. This review summarizes and discusses several analytical methods involving the preparation and use of new solid phase extractant. A literature survey of the last ten years offering a critical review of these new sorbents available for use in trace analyte enrichment is provided.

3

Study of Stannous-Cerium Oxide Nanocomposites as Nanofilm, Nanodot and Nanorod

Budhiraja N, Sharma A., Kumar S., Kaur A., Unikrishnan N. V.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 14

69--79

EN

In the present paper, main emphasis is given to synthesize the Stannous-Cerium oxide nanocomposites in nanofilms, nanodots and nanorods by Chemical bath method, Chemical drop method and Chemical rolling Method. These nanocomposite materials are synthesized on a glass substrate at 100 °C temperature. Crystallography investigation of these materials is done by X-ray diffraction (XRD) which reveals that average grain size is 58.9 nm and 62.3 nm for nanofilms and nanodots on glass substrate respectively whereas XRD diffraction for nanorod on glass substrate reveals that material is amorphous in nature.