Supplementary cementitious materials: New sources, characterization, and performance insights

From dredged sediment to supplementary cementitious material: characterization, treatment, and reuse

Dam siltation is an alarming problem that significantly affects the dam's lifetime and water storage capacity. In Algeria, the removal of dredged sediment has become a significant environmental impact and an economic issue. In this context, the utilization of calcined sediments as an artificial pozzolanic material could reduce greenhouse gas emissions in the cement industry. This paper addresses the objective of valorizing calcined sediments in sustainable mortar production on fresh and hardened states of grouts and mortars. Moreover, three dry curing methods were used to accelerate improving the strength of the different mortars at a rate of 5, 15, and 25% by weight of Portland cement (CEM I 42.5 N). The first method was applied at 10 °C, and the other two at 20 °C and 40 °C. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) analysis showed a real advantage of heat treatment at 750 °C of sediments to acquire pozzolanic behavior. A substitution rate of 25% affected the fluidity of cement grouts with calcined sediments at 60 min with a loss of fluidity, even with a high dosage of plasticizer. Indeed, the best mechanical results of the mortars were observed at cure temperatures of 20 °C and 40 °C. With an acceleration of the pozzolanic activity at 90 days for a cure at 40 °C and 180 days at 20 °C, the development of compressive strength is relatively higher than that of the control mortar. In conclusion, the carbon footprint of the final mortars showed that a high substitution rate reduces CO 2 emissions, representing a reduction of 3%, 10%, and 17% respectively for the formulation of mortars based on 5%, 15%, and 25% calcined sediment.

Reusing calcined sediments from Chorfa II dam as partial replacement of cement for sustainable mortar production

3D acid diffusion model for FRP-strengthened reinforced concrete structures: long-term durability prediction

Life cycle assessment of cementitious materials based on calcined sediments from Chorfa II dam for low carbon binders as sustainable building materials.

Hydraulic facilities are subjected to significant siltation which, in a very short period of time, can render them unusable. In Algeria, the silting-up of a great number of dams, built for drinking water needs and for irrigation, implies the necessity and urgency to take action. Therefore, the maintenance work, which leads to dredging the deposited silt, constitutes an unbearable obligation for the preservation of the environment. Chorfa dam (western Algeria) may be mentioned as a concrete example. This study is part of a long research whose objective is to contribute to the valorization and the optimization of the formulations economically that are easy to implement and which enable to use the dredged materials in the formulation of ordinary concretes by partial substitution to cement (10, 20 and 30%) of dredged sediments, after calcination at 750 °C to make them active. Tests were carried out on concrete that was vibrated in the fresh state (setting time) and hardened state (compressive strengths and durability of concrete exposed to sulfuric acid attack) in order to determine their characteristics. The results obtained confirmed the possibility to develop concretes containing calcined silt, with proportions up to 30%, and which can meet the economic, ecological and technological objectives.

/pdf/valorization-of-dredged-sediments-as-a-component-of-vibrated-4b3wn7zr3z.pdf

Valorization of Dredged Sediments as a Component of Vibrated Concrete: Durability of These Concretes Against Sulfuric Acid Attack

All the dams in the world are exposed to the phenomenon of sedimentation, but with velocities that differ from one region to another. This phenomenon has been widely reported in Algeria. Dredging is a vital activity in the operation of dams, but the amount of sediment discharged by dredging operations downstream of the structure can lead to long-term pollution of the rural environment. This study focuses on the valorization of the vases resulting from these dredging operations at the dams as the case of Chorfa dam (western Algerian). The objective is to propose economically competitive formulations that are easy to implement and which allow these materials to be used in the manufacture of ordinary concretes by partial substitution of cement (10, 20 and 30%). The sludge is treated by calcination at 750°C to make it active. Seawater attack tests were conducted on the concretes to determine their durability. The results obtained confirmed the possibility of developing concretes incorporating the calcinated sludge at dosages of up to 30% without compromising the quality of these concretes in terms of behavior against seawater aggressions meeting the economic, ecological and technological objectives.

/pdf/resistance-of-concrete-based-on-treated-mud-to-sea-water-2vz9ettpg1.pdf

Resistance of concrete based on treated mud to sea water attack

This paper describes the design and simulation of a wide band corrugated conical horn feed for satellite and very small aperture terminal applications dedicated to parabolic reflectors. The design was performed using CST software. The proposed design operates in the frequency range of 12 to 14.25 GHz (Ka band) such as 12 GHz to 13 GHz for the uplink and for the down link from 13.25 GHz to 14.25 GHz. The horn feed is linearly polarized due to the feeding of a rectangular waveguide with TE10 mode. Simulation results show good Ku-band radiation characteristics including S-parameter.

Design of a Ku Band Corrugated Conical Feed Network For Parabolic Antennas

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Omar Safer

Author Tools

Chat about Author

Papers

Valorization of Dredged Sediments as a Component of Vibrated Concrete: Durability of These Concretes Against Sulfuric Acid Attack

Resistance of concrete based on treated mud to sea water attack

Design of a Ku Band Corrugated Conical Feed Network For Parabolic Antennas