Mechanical Properties and Self-Healing Mechanism of Epoxy Mortar (original) (raw)
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Performance of Epoxy Resin Polymer as Self-Healing Cementitious Materials Agent in Mortar
Materials, 2021
This research investigated the application of epoxy resin polymer as a self-healing strategy for improving the mechanical and durability properties of cement-based mortar. The epoxy resin was added to the concrete mix at various levels (5, 10, 15, and 20% of cement weight), and the effectiveness of healing was evaluated by microstructural analysis, compressive strength, and non-destructive (ultrasonic pulse velocity) tests. Dry and wet-dry conditions were considered for curing, and for generating artificial cracks, specimens at different curing ages (1 and 6 months) were subjected to compressive testing (50 and 80% of specimen’s ultimate compressive strength). The results indicated that the mechanical properties in the specimen prepared by 10% epoxy resin and cured under wet-dry conditions was higher compared to other specimens. The degree of damage and healing efficiency index of this particular mix design were significantly affected by the healing duration and cracking age. An opt...
Investigate The Engineering Properties of Epoxy-Modified Mortars As Self-Healing Materials
The aim of this study as mentioned above is to investigate the properties of Mortars to develop a self-healing polymeric-cementitious material using polymeric admixture, epoxy resin (Diglycidyl Ether of Bisphenol A Type). This study investigates the engineering properties of epoxy-modified mortars as self-healing materials. In this research an epoxy resin (diglycidyl ether of bisphenol A) without any hardener is used as polymeric admixture to prepare polymeric-cementitious materials and their self-healing function is evaluated. Epoxy-modified mortars are prepared with various polymer-cement ratios, subjected to initial wet/dry curing plus long term dry curing and tested for strength properties. The fundamental properties such as workability, influence of curing, strength development and water absorption are investigated. The results show that 10% of polymer - cement and wet dry curing was optimum to modify the strength properties of mortar.
Performance of Epoxy Resin as Self-Healing Agent
Jurnal Teknologi, 2015
Formation of cracks due to the shrinkage effects during curing and mechanical loading can deteriorate the concrete performance especially in terms of durability aspect. Chemical and harsh solutions will easily penetrate into the concrete and cause damage to the concrete. In order to solve this problem, researchers have introduced a selfhealing concrete; the mechanism of automatically repairing concrete cracks without external intervention. Nowadays, the self-healing concrete by using bacteria as a healing agent had gained interest among researchers. In contrast, this paper presents the study on performance of epoxy resin without hardener as a self-healing agent in concrete. Mortar specimens were prepared with mass ratio of 1:3 (cement: fine aggregates), water-cement ratio of 0.48 and 5 to 20% epoxy resin of cement content. All tested specimens were subjected to wet-dry curing; where compressive strength, apparent porosity and self-healing evaluation were measured. Result shows that, the compressive strength of mortar with addition of epoxy resin by 10% increased significantly compared to normal mortar. Epoxy resin as a healing agent was found to be functioned well as the compressive strength and ultrasonic pulse velocity regain the initial reading with prolonged curing time. These results together with microstructure test indicate that epoxy resin can be used as a selfhealing agent.
Synthesis and Characterization of Self-Healing Mortar with Modified Strength
Jurnal teknologi, 2015
Cementitious materials being the most prospective building blocks achieving their absolute strength to avoid the deterioration in the early stage of service life is ever-demanding. Minimizing the labor and capital-intensive maintenance and repair cost is a critical challenge. Thus, self-healing mortars with modified strength are proposed. Lately, selfhealing of micro-cracks by introducing bacteria during the formation of mortar or concrete became attractive. Self-healing with polymeric admixtures is considered to be relatively more durable and faster process. Certainly, the self-healing of synthetic polymeric materials is inspired by biological systems, where the damage triggers an autonomic healing response. This emerging and fascinating research initiative may significantly improve the durability and the safety limit of the polymeric components potential for assorted applications. In this work, using epoxy resin (diglycidyl ether of bisphenol A) without any hardener as admixture polymeric-cementitious materials is prepared. These epoxy-modified mortars are synthesized with various polymer-cement ratios subjected to initial wet/dry curing (WDC) together with long term dry curing (DC). Their self-healing function and hardening effects are evaluated via preloading and drying of the specimens, chemical analysis, and ultrasonic pulse velocity testing. It is demonstrated that 10% of polymer is the best proportion for polymer-cement ratio. Furthermore, the wet/dry curing is established to be superior process for healing hairline cracks present in the mortar. The excellent features of the results suggest that our novel method may constitute a basis for improving the compressive strength and self-healing features of mortars.
Effect of Incorporation of Various Chemicals in Self-Healing Property of Mortar
Concrete is one of the widely used building material in the world and chief agent which does the binding of all the compounds is cement. Deterioration of concrete structure takes place due to cracks in the concrete. In order to minimize the crack formation an attempt is made to incorporate self-healing compound. Few of the self-healing compounds that can be introduced are urea, calcium formate and calcium acetate. Various dosage of urea was added and its effect on three parameters consistency, setting time and compressive strength was evaluated. Optimum dosage of urea was found to be 2.5% beyond which incorporation in cement paste will lead to decrease in compressive strength. Similarly, when 2.5% of cement is replaced by calcium formate and calcium acetate it will lead to significant change in compressive strength.
AN EXPERIMENTAL STUDY ON STRENGTH AND FRACTURE PROPERTIES OF SELF HEALING CONCRETE
Cracking in concrete is irresistible when the load applied is more than its limit and the treatment of cracks is very expensive. This phenomenon also affects the reinforcement in the structure by means of carbon dioxide and water through the cracks. One of the ways to arrest this cracking phenomenon is mixing of bacteria into the concrete. In the present study, an attempt is made to arrest the cracks in concrete using bacteria and calcium lactate. The percentages of bacteria selected for the study are 3.5% and 5% by weight of cement. In addition, calcium lactate was used at 5% and 10% replacement of cement by weight. Bacteria produce calcium carbonate crystals which blocks the micro cracks and pores in the concrete after reacting with calcium lactate. The bacterial selection depends upon the alkaline environment, where bacteria have to survive. This bacterial concrete improves the compressive strength of concrete which was found by experimental study. Bacillus pasteurii is adopted for this study. Various tests such as compressive strength, elastic modulus and fracture of concrete were analyzed in this study.
An experimental study on damaged cementitious mortars repaired by glass/epoxy composite materials
Selected scientific papers, 2020
This paper presents an experimental investigation on the post-repair flexural response of mortars with and without damage. In order to improve the mechanical properties of the damaged mortars, which were subjected to different loads ranging between 40 % and 90 %, the mortars specimens were reinforced and repaired using two different composite materials, the first with only epoxy resin, while the second consisted of a mixture of epoxy resin and glass fiber. The results show a significant improvement in the stiffness damaged. Therefore, the reinforced specimens by a layer of resin on the lower side surface increased the bending strength by 58 %, when compared to those control samples. The reinforcement using composite resin-fiber of glass exhibited considerable increases in the safety of constructions. The SEM images of damaged samples with and without repair, revealed the impact of reinforced glass fibers-mortar on the matrix-mortar by improving theirs mechanical performances.
Research on the production of cement composites with autonomous self-healing performance
MATEC Web of Conferences
In a time when the attention paid to identifying the possibilities of reducing problems due to urban pollution is increasing, the construction industry has a lot to gain if it aligns itself with the new trends of sustainable development in the field. In this context, the objective of obtaining a concrete with self-healing properties of cracks is more than appropriate, becoming a sustainable alternative for reducing the maintenance costs of transport infrastructure by increasing their operating time and by decreasing the need for the volume of repair and maintenance works, thus indirectly contributing to the reduction of environmental pollution. Preliminary results obtained using a cementitious composite with waterproofing admixture content by mass crystallization are encouraging by identifying the existence of an autonomous healing degree (closure of cracks with average opening 20-40 µm) in a proportion of at least 65% after only 96 hours of exposure in a wet-dry environment, respec...
Self-Healing Concrete Mix-Design Based on Engineered Cementitious Composites Principles
The 14th International Conference on Interdisciplinarity in Engineering—INTER-ENG 2020, 2020
Concrete is the most used material in the construction industry, being prone to cracking. Following the action of aggressive external agents, through cracks, access routes to the embedded reinforcement are created. By enclosing in concrete various materials that can induce the self-healing property, by taking actions when the cracks appear, the access of the external aggressive agents to the reinforcement can be stopped, therefore creating more durable materials. The aim of the research is to design a micro concrete with self-healing properties, based on Engineered Cementitious Composites principles from the literature and using local raw materials.
2015
In this research, cementitious hollow tubes were produced by extrusion and used as healing agent containers that were embedded in the mortar matrix to obtain self-healing properties. Based on the results of preliminary mechanical tests, sodium silicate, potassium silicate and Primal (a commercial acrylic resin) were first selected as healing agents. To determine their efficiency, three-point bending test were performed on samples with the different healing agents and load, as well as, stiffness recovery indexes were determined. It was first observed that modulus of rupture and elastic modulus were not affected because of the presence of the capsules inside the samples with respect to plain mortar samples.