An Application of Rice Husk Ash (RHA) and Calcium Carbonate (CaCo3) as Materal for Self-Healing Cement

2016 ◽  
Vol 673 ◽  
pp. 3-12
Author(s):  
Januarti Jaya Ekaputri ◽  
Fahmi Firdaus Alrizal ◽  
Iqbal Husein ◽  
Triwulan ◽  
Mohd Mustafa Al Bakri Abdullah
Keyword(s):  
Calcium Carbonate ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Healing Process ◽  
Crack Depth ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Self Healing ◽  
Concrete Technology

Self-healing cement is a novel topic in concrete technology. Concrete is created to have its own ability to heal cracks. Crack closure is due to the material deposition of the gap so causing the crack closed. Materials used in this paper is mortar composition with ordinary portland cement replaced by calcium carbonate (CaCO3) and rice husk ash. There are three testing presented in this paper. The first is compressive test to determine the compression applied to mortar for initial cracks. The second is an ultrasonic pulse velocity (UPV) test to observe the depth of cracks and density of each composition. The third is macroscopic investigation to observe cracks wide in each mixture. The maximum compressive strength of 22.46 MPa shown by specimens made with 10% rice husk ash and 10% calcium carbonate cement. By the end of healing process, it reached 23.18 MPa. It was also shown that in crack depth decreased from 38 mm to 16 mm. From this analysis, it can be concluded that rice husk ash (RHA) and calcium carbonate (CaCO3) can be utilized as self-healing concrete materials.

scholarly journals Monitoring the Self-healing of Concrete from the Ultrasonic Pulse Velocity

2019 ◽  
Vol 3 (1) ◽  
pp. 16 ◽  
Author(s):  
Letícia Camara ◽  
Mayara Wons ◽  
Ian Esteves ◽  
Ronaldo Medeiros-Junior
Keyword(s):  
Fly Ash ◽  
Healing Process ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Ultrasonic Waves ◽  
The Self ◽  
Self Healing ◽  
Wetting And Drying ◽  
Rate Characteristic

Concrete has the ability to naturally heal its cracks, in a process called self-healing. This article aimed to analyze the self-healing of concretes, evaluating the influence of fly ash and the age of occurrence of cracks. Concrete specimens were submitted to cracking at 7 and 28 days. Subsequently, the samples were exposed to 12 wetting and drying cycles in order to favor the self-healing process. The phenomenon was evaluated through the ultrasonic pulse velocity testing, performed weekly on the specimens from the molding stage until the end of all cycles. The concretes showed a decrease in ultrasonic pulse velocity at the time they were cracked. This is due to the greater difficulty in the propagation of ultrasonic waves in the voids formed during cracking. This drop was higher for concrete with fly ash. Also, the results show that the fly ash concretes presented a more expressive self-healing process when cracked at 28 days, which may be related to the presence of pozzolanic reactions and the presence of more anhydrous particles. The concretes without fly ash had self-healing when they were cracked at 7 days. This is explained by the high hydration rate characteristic of ordinary Portland cement.

scholarly journals Transport Properties and Resistance Improvement of Ultra-High Performance Concrete (UHPC) after Exposure to Elevated Temperatures

Buildings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 416
Author(s):  
Yunfeng Qian ◽  
Dingyi Yang ◽  
Yanghao Xia ◽  
Han Gao ◽  
Zhiming Ma
Keyword(s):  
Compressive Strength ◽  
Transport Properties ◽  
High Temperatures ◽  
High Performance ◽  
High Performance Concrete ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Capillary Absorption ◽  
Self Healing

Ultra-high performance concrete (UHPC) has a high self-healing capacity and is prone to bursting after exposure to high temperatures due to its characteristics. This work evaluates the damage and improvement of UHPC with coarse aggregates through mechanical properties (compressive strength and ultrasonic pulse velocity), transport properties (water absorption and a chloride diffusion test), and micro-properties such as X-ray diffraction (XRD), Mercury intrusion porosimetry (MIP), and Scanning electronic microscopy (SEM). The result demonstrates that polypropylene (PP) fibers are more suitable for high temperature tests than polyacrylonitrile (PAN) fibers. The result shows that 400 °C is the critical temperature point. With the increase in temperature, the hydration becomes significant, and the internal material phase changes accordingly. Although the total pore volume increased, the percentage of various types of pores was optimized within 400 °C. The mass loss gradually increased and the ultrasonic pulse velocity gradually decreased. While the compressive strength first increased and then decreased, and the increase occurred within 25–400 °C. As for the transport properties, the chloride migration coefficient and capillary absorption coefficient both increased dramatically due to the higher sensitivity to temperature changes. The results of the property improvement test showed that at temperatures above 800 °C, the compressive strength recovered by more than 65% and the ultrasonic pulse velocity recovered by more than 75%. In terms of transport properties, compared to the results before self-healing, the chloride migration coefficient decreased by up to 59%, compared with 89% for the capillary absorption coefficient, after self-healing at 800 °C. With respect to the enhancement effect after exposure to high temperatures, the environment of a 5% Na2SO4 solution was not as good as the clean water environment. The corresponding changes in microstructure during the high temperatures and the self-healing process can explain the change in the pattern of macroscopic properties more precisely.

SYNTHESIS AND CHARACTERIZATION OF SELF-HEALING MORTAR WITH MODIFIED STRENGTH

2015 ◽  
Vol 76 (1) ◽  
Author(s):  
Gassan Fahim Huseien ◽  
Jahangir Mirza ◽  
Nur Farhayu Ariffin ◽  
Mohd Warid Hussin
Keyword(s):  
Early Stage ◽  
Polymeric Materials ◽  
Building Blocks ◽  
Ultrasonic Pulse Velocity ◽  
Cementitious Materials ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Diglycidyl Ether ◽  
Self Healing ◽  
Research Initiative

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, self-healing 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.    

Estimating Crack Depth of Concrete Structures Using Ultrasonic Pulse Velocity

2012 ◽  
Vol 496 ◽  
pp. 546-549
Author(s):  
Young S. Cho ◽  
Sang Woo Han ◽  
Hyun Suk Jang ◽  
Sang Ki Baek ◽  
Seong Uk Hong
Keyword(s):  
Human Life ◽  
Crack Depth ◽  
Concrete Structures ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Concrete Crack ◽  
Long Time ◽  
Close Range ◽  
Non Destructive

The concrete structures have the quite close linkage on the human life and it is used for a long time. Therefore, the importance for structure safety had been being continuously increased. The general method in order to measure concrete crack is the non destructive inspection. This method is known efficiently when it is difficult to check the crack through the eyes because of not exposed. Hence, the purpose of this study is measuring a crack depth of concrete by using the ultrasonic pulse velocity. And the Pundit that is one among the supersonic equipment was used in order to proceed with this research. In the first place used the existing methods (Tc-To, BS, T, close range bypass wave) in order to estimate crack depth of concrete. And then new method that the BS method and the T method are combined make an attempt to analyze the error.

scholarly journals Behaviour of Incorporation of Bacteria in Concrete

2021 ◽  
Vol 889 (1) ◽  
pp. 012022
Author(s):  
Aditya Kumar Tiwary
Keyword(s):  
Flexural Strength ◽  
Healing Process ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Conventional Concrete ◽  
Concrete Crack ◽  
Micro Cracks ◽  
Enterobacter Species ◽  
Compressive Strength Of Concrete

Abstract The life of the healing in concrete is many years old and when the study was done on this, outcomes were coinciding with the auto-genus healing process which was capable to heal the micro cracks inside cementitious based materials and hereafter research led to the study of autonomous healing. In the autonomous healing process, the main aim was to fill the cracks and heal the fracture at the macro level. This was possible with the help of bacteria that were embedded in the cementitious based material with different technologies and methods. In this paper, Enterobacter species and Cohnii bacteria were incorporated into concrete. The behaviour of bacterial concrete was investigated in terms of compressive, tensile, flexural strength and ultrasonic pulse velocity. It observed that the compressive strength of concrete was increased by 11.5%, flexural strength increased by 11.9%, tensile strength increased by 12.8% with the replacement of Cohnii bacteria as compare to conventional concrete. These bacteria have been proved a positive approach to the healing process in cementitious based material. Also, the important criterion has been studied which is essential when dealing with the autonomous healing process. Both the bacteria generate the calcite that helps to fill the concrete crack and voids if water come in to contact.

Self-Healing Mortar

2019 ◽  
pp. 135-148
Keyword(s):  
Epoxy Resin ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Experimental Program ◽  
Self Healing ◽  
Repair Materials ◽  
Healing Agent ◽  
The Cost ◽  
Initial Reading

The cost of repairing cracked concrete is expensive as it requires special repair materials and skilled labour. Thus, the developments of new materials, like self-healing materials, are highly needed to repair cracks automatically and to restore or even increase concretes' strength to prolong its service life. The aim of this chapter was to investigate the performance of epoxy resin without hardener as a self-healing agent in mortar. A detailed introduction of self-healing mortar is given followed by a problem statement. The epoxy resin as a self-healing material is also explained briefly. Self-healing concept is also discussed in detail followed by the experimental program. Results revealed that the epoxy resin without hardener as a healing agent performed effectively as the compressive strength and ultrasonic pulse velocity of 365 days old cracked mortar samples regained the initial reading with prolonged curing time.

scholarly journals Performance of Epoxy Resin Polymer as Self-Healing Cementitious Materials Agent in Mortar

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1255 ◽  
Author(s):  
Ghasan Fahim Huseien ◽  
Abdul Rahman Mohd Sam ◽  
Iman Faridmehr ◽  
Mohammad Hajmohammadian Baghban
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Epoxy Resin ◽  
Healing Process ◽  
Microstructural Analysis ◽  
Ultrasonic Pulse Velocity ◽  
Cementitious Materials ◽  
Pulse Velocity ◽  
Self Healing ◽  
Dry Conditions

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 optimized artificial neural network (ANN) combined with a firefly algorithm was developed to estimate these indexes over the self-healing process. Overall, it was concluded that the epoxy resin polymer has high potential as a mechanical properties self-healing agent in cement-based mortar.

Sign in / Sign up

Export Citation Format

Share Document