Related Experiment Video
Updated: Nov 17, 2025
05:38
Production and Analysis of Sporosarcina pasteurii Biocement Bricks Using Custom 3D-Printed Molds for Unconfined Compression Tests
Published on: March 7, 2025
626
Modified self-healing cementitious materials based on epoxy and calcium nitrate microencapsulation.
Fahimeh Farshi Azhar1, Aylin Ahmadinia1, Alireza Mohammadjafari Sadeghi2
1Applied Polymer Research Laboratory, Department of Chemistry, Faculty of Sciences, Azarbaijan Shahid Madani University, Tabriz, Iran.
Journal of Microencapsulation
|February 15, 2021
Summary
This study developed microcapsules containing epoxy and calcium nitrate to effectively heal micro-cracks in cementitious materials, restoring mechanical properties and enhancing durability.
Area of Science:
- Materials Science
- Civil Engineering
- Nanotechnology
Background:
- Cementitious materials are prone to micro-cracking, compromising their mechanical integrity and durability.
- Effective self-healing systems are crucial for extending the service life of concrete structures.
Purpose of the Study:
- To develop and utilize microencapsulated healing agents for self-healing cementitious materials.
- To investigate the effectiveness of microcapsules in restoring mechanical properties of cracked concrete.
Main Methods:
- Microencapsulation of epoxy and calcium nitrate within a urea-formaldehyde shell.
- Characterization of microcapsules using FTIR, TGA, DSC, FESEM, and EDX.
- Incorporation of microcapsules (0-6% w/w) into cementitious mortar samples.
- Evaluation of healing efficiency based on mechanical property recovery rates.
Main Results:
- Microcapsules exhibited suitable size (1-100 µm), shell thickness (0.2-0.6 µm), and thermal stability up to 260°C.
- Complete healing of micro-cracks was observed in cementitious samples.
- Mechanical properties recovered to over 100% of their original values.
Conclusions:
- The developed microcapsules effectively seal micro-cracks in cementitious materials.
- The self-healing system significantly improves the durability and mechanical performance of concrete.
- The microcapsules also contribute to enhanced thermal stability of the material.
Related Concept Videos
01:21Types of Cement I
236
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...
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...
236
01:22Types of Cement II
252
Portland blast-furnace cement is made by blending Portland cement clinker with granulated blast-furnace slag, which accounts for 25 to 65 percent of the cement's weight. Despite its similarities to ordinary Portland (Type I) cement in terms of fineness and setting times, its early strength is lower, though it achieves comparable strength later on. It's particularly suited for mass concrete structures and marine environments due to its lower heat of hydration and superior sulfate...
252
01:20Curing of Concrete
241
The hydration of cement takes place within the water-filled capillary pores. However, environmental elements can disrupt this process by evaporating water from the concrete surfaces. Sealed concrete with a water-cement ratio below 0.5 experiences self-desiccation, leading to water loss. The water loss in concrete is mitigated by curing. This technique involves keeping the concrete saturated to maintain the necessary temperature and moisture conditions, to optimally fill the spaces in the cement...
241
01:24Hydration of Cement
514
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...
514
01:17Accelerators
150
Accelerators in concrete serve as admixtures to speed up the hardening process, enabling the concrete to achieve early strength faster. Although accelerators do not necessarily impact the time it takes concrete to set, they reduce this time in practice. A common accelerator is calcium chloride, which is particularly useful for hastening early strength development in cold weather or for rapid repair jobs that require quick heat generation after mixing.
The effectiveness of calcium chloride can...
The effectiveness of calcium chloride can...
150
01:25Accelerated Curing of Concrete
321
Accelerating concrete curing is achieved by applying heat and additional moisture. This process accelerates the hydration of the cement, resulting in an earlier strength gain in the concrete. Steam curing is a method wherein the concrete products are either transported through a chamber on a conveyor belt or encased in plastic, allowing steam at atmospheric pressure to circulate freely around them. This process begins with a phase of moist curing that typically lasts between 3 to 5 hours, after...
321