Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Hydration of Cement01:24

Hydration of Cement

1.0K
Hydration of cement is a chemical reaction between cement particles and water. This process occurs primarily through two mechanisms: through-solution and topochemical. In the through-solution process, anhydrous compounds dissolve into their constituents, hydrates form in the solution, and then precipitate from the supersaturated solution. The topochemical process involves solid-state reactions at the cement particle surface. The through-solution process dominates the topochemical process at the...
1.0K
Setting Time of Cement01:12

Setting Time of Cement

772
The setting time of cement refers to the process of cement paste transitioning from a plastic state to a solid state. This process is crucial in construction as it dictates the timeframe for concrete placement, compaction, and finishing. The onset of this solidification is termed the initial set, indicating when the paste becomes unworkable. The final set is when the paste has solidified completely, and further handling or manipulation can no longer affect its shape. The cement strength is...
772
Strength and Heat of Hydration01:29

Strength and Heat of Hydration

766
The hydration of cement is an exothermic reaction in which heat is generated as cement hydrates. This heat of hydration is critical to cement's strength development. The rate at which this heat is generated affects the temperature rise, with a majority of the heat being released early in the hydration process, half within the first three days, and about 75% within the first week.
The heat of hydration for each cement compound is significant; for instance, tricalcium aluminate (C3A) and...
766
Pozzolans01:21

Pozzolans

616
Pozzolans are siliceous or aluminous materials blended with Portland cement. They interact with the calcium hydroxide produced during the hydration of Portland cement and contribute to improved strength and durability of concrete. The pozzolanic activity, a measure of a pozzolan's effectiveness, is typically assessed using the strength activity index, as defined in ASTM C 618-93, which calculates the ratio of the compressive strength of cement mixtures with and without pozzolan.
Fly ash is...
616
Transition Zone01:28

Transition Zone

430
The transition zone in concrete is a critical area where aggregate meets cement paste, marked by a distinct porosity and weakness compared to the surrounding material. The adhesion around the aggregates is primarily due to Van Der Waals forces. The voids within this zone influence its robustness; initially, it is less durable than the surrounding bulk mortar due to larger voids. Initially, when concrete is compacted, a higher water-cement ratio near the aggregates leads to the formation of...
430
Types of Cement I01:21

Types of Cement I

428
Portland cement comes in several types, each with distinct properties and applications based on their chemical composition and hydration characteristics:
Type I (Ordinary Portland Cement) is widely used for general construction where special properties are not required. It has moderate sulfate resistance and heat of hydration.
Type II (Modified Cement) offers moderate resistance to sulfate attack and a lower rate of heat development compared to Type I. It is suitable for structures in...
428

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Visualization of the influence of sodium citrate on iron and uranium precipitation in a 2D laboratory scale tank.

Journal of contaminant hydrology·2026
Same author

Correction to "Halloysite/polyaniline Nanocomposites for Enhanced Actinide Sorption".

ACS applied materials & interfaces·2026
Same author

Arthroscopically Resected Ganglion Cyst Arising From the Infrapatellar Fat Pad: A Report of Two Cases.

Cureus·2025
Same author

Multiple Sources of Riparian Wetland Suspended Solids during Episodic Rain Events: Influence on Uranium Transport.

Environmental science & technology·2025
Same author

Evaluation of Cartilage Degeneration Using MRI T1ρ Mapping after Locomotion Training in Patients with Early Knee Osteoarthritis.

Progress in rehabilitation medicine·2025
Same author

Halloysite/polyaniline Nanocomposites for Enhanced Actinide Sorption.

ACS applied materials & interfaces·2025

Related Experiment Video

Updated: Feb 23, 2026

Two-way Valorization of Blast Furnace Slag: Synthesis of Precipitated Calcium Carbonate and Zeolitic Heavy Metal Adsorbent
11:14

Two-way Valorization of Blast Furnace Slag: Synthesis of Precipitated Calcium Carbonate and Zeolitic Heavy Metal Adsorbent

Published on: February 21, 2017

12.9K

Residence time effects on technetium reduction in slag-based cementitious materials.

Yuji Arai1, Brian A Powell2, D I Kaplan3

  • 1Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.

Journal of Hazardous Materials
|September 8, 2017
PubMed
Summary

Long-term disposal of technetium-99 (99Tc) in slag-based grout shows promising stability. Reduced technetium (Tc(IV)) species, stabilized by sulfur compounds, remain intact even after aging, indicating effective immobilization in radioactive waste.

Keywords:
Cementitious materialsGroutImmobilizationReductionSlagTechnetiumXAS

More Related Videos

Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor
15:19

Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor

Published on: October 15, 2015

10.2K
Assessing Disaster Resilience of Concrete with Titanium Dioxide Nanoparticles
05:45

Assessing Disaster Resilience of Concrete with Titanium Dioxide Nanoparticles

Published on: November 14, 2025

362

Related Experiment Videos

Last Updated: Feb 23, 2026

Two-way Valorization of Blast Furnace Slag: Synthesis of Precipitated Calcium Carbonate and Zeolitic Heavy Metal Adsorbent
11:14

Two-way Valorization of Blast Furnace Slag: Synthesis of Precipitated Calcium Carbonate and Zeolitic Heavy Metal Adsorbent

Published on: February 21, 2017

12.9K
Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor
15:19

Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor

Published on: October 15, 2015

10.2K
Assessing Disaster Resilience of Concrete with Titanium Dioxide Nanoparticles
05:45

Assessing Disaster Resilience of Concrete with Titanium Dioxide Nanoparticles

Published on: November 14, 2025

362

Area of Science:

  • Geochemistry
  • Materials Science
  • Environmental Science

Background:

  • Technetium-99 (99Tc) immobilization is crucial for low-level radioactive waste disposal.
  • Slag-based grout, utilizing blast furnace slag, fly ash, and Portland cement, is a potential matrix for 99Tc.
  • Long-term stability of reduced technetium (Tc(IV)) species in grout under oxidizing conditions is not well understood.

Purpose of the Study:

  • To investigate the aging effects on technetium speciation within slag-based grout.
  • To assess the long-term stability of immobilized 99Tc(VII)O4-(aq) as it transforms into Tc(IV) species.
  • To understand the role of sulfur and iron species in stabilizing Tc(IV) over time.

Main Methods:

  • X-ray absorption spectroscopy (XAS) was employed to analyze Tc speciation.
  • Samples were analyzed at various depths (<2.5cm) and aging times (up to 485 days).
  • Changes in iron (Fe) and sulfur (S) speciation were correlated with Tc stability.

Main Results:

  • Iron(II) in the grout was fully oxidized to Iron(III) within 117 days.
  • Elemental sulfur, sulfide, and sulfoxide persisted in the grout up to 8mm depth after 485 days, indicating a reduced zone.
  • Pertechnetate (99Tc(VII)O4-) was reduced to Tc(IV) within 29 days.
  • Distorted, hydrolyzed Tc(IV) octahedral molecules were found to be partially sulfidized and/or polymerized.
  • These Tc(IV) species remained stable in samples aged for 485 days.

Conclusions:

  • Variable sulfur species play a key role in stabilizing partially sulfidized Tc(IV) species within aged slag-based grout.
  • The persistence of reduced sulfur species contributes to maintaining a reductive environment.
  • Slag-based grout demonstrates potential for long-term immobilization of 99Tc in radioactive waste.