scholarly journals Self-Healing Performance Evaluation of Concrete Incorporating Inorganic Materials Based on a Water Permeability Test

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3202
Author(s):  
Kwang-Myong Lee ◽  
Hyung-Suk Kim ◽  
Do-Keun Lee ◽  
Kyung-Joon Shin
Keyword(s):  
Water Permeability ◽  
Standardized Test ◽  
Water Flow Rate ◽  
Test Methods ◽  
Inorganic Materials ◽  
Self Healing ◽  
Permeability Test ◽  
Research Activities ◽  
Number Of Factors ◽  
Rational Evaluation

Research activities that have focused on the development and understanding of self-healing concrete have proposed various technologies intended to enhance self-healing capacity. The self-healing performance cannot be identified sufficiently with either a single test or a specific parameter because there are a number of factors that influence the performance of self-healing. Thus, it has become necessary to provide standardized test methods that make it possible to verify and compare the performance of self-healing materials. In this paper, self-healing mortars based on inorganic admixtures, which are developed for sealing 0.3 mm cracks with a healing index of 90%, are produced and used to validate the water permeability test and to propose protocols for the evaluation of self-healing performance. The healing performances of three self-healing mortars and a plain mortar as a reference are evaluated with a comparative study. The equivalent crack width, which can be estimated from the water flow rate, is suggested as a rational evaluation index. Finally, a self-healing performance chart is proposed to comprehensively show the healing performance of cement-based materials.

Comparison of Standardized Test Methods for Determining the Permeability of the Surface Layer of Concrete

2015 ◽  
Vol 1122 ◽  
pp. 141-144
Author(s):  
Tereza Komárková ◽  
Monika Králíková ◽  
Dalibor Kocáb ◽  
Petr Misák ◽  
Tomáš Stavař
Keyword(s):  
Surface Layer ◽  
Water Permeability ◽  
Standardized Test ◽  
Test Methods ◽  
Standardized Assessment ◽  
Depth Of Penetration ◽  
The Individual ◽  
Durability Of Concrete

The durability of concrete can be assessed based on the quality of the surface layer of concrete, for which there are a few standardized assessment test methods. Usually, the quality of the surface layer of concrete is evaluated based on its air and water permeability. The aim of this experiment was to compare the outputs which provide some methods for determining the permeability of the surface layer of concrete (GWT, ISAT, TPT, the depth of penetration of water under pressure). The measured values using the individual methods of assessing the permeability of the surface layer of concrete very closely correspond.

Experimental Full-Scale Test Cell Optimizing for Research of Novel Concepts towards Climatically Active Solar Façade Design

2016 ◽  
Vol 861 ◽  
pp. 213-220 ◽  
Author(s):  
Miroslav Čekon ◽  
Richard Slávik ◽  
Karel Struhala ◽  
Marian Formánek
Keyword(s):  
Numerical Models ◽  
Test Methods ◽  
Full Scale ◽  
Test Cell ◽  
Full Scale Test ◽  
Climate Conditions ◽  
Outdoor Climate ◽  
Research Activities ◽  
Building Components ◽  
Scale Test

The passive solar test facilities have recently been created in many research centers all over the world to analyse dynamic outdoor phenomena on buildings and their components. The main objective of these research activities is primarily to evolve a methodology, improve test methods, validate numerical models and measure real thermodynamic properties of building components under outdoor climate conditions. An integration of advanced material solutions into buildings need to be investigated within specific conditions related specifically to outdoor test methods. A research project on Contemporary concepts of climatically active solar facades at the Brno University of Technology does have an ambition to create an experimental full-scale test cell for research of thermal aspects in progressive advances of future solar façade concepts exposed to the real climate conditions. This paper describes the design optimization phase preceding the test cell assembly. This phase includes the analysis of energy and thermal properties based on parametric study features. Computer simulations based on finite element and volume methods are involved in the optimization process. The proposed optimized test cell design is confronted with parametrization of typical thermal aspects to present final test cell demonstration.

scholarly journals Effect of crack pattern on the self-healing capability in traditional, HPC and UHPFRC concretes measured by water and chloride permeability

2019 ◽  
Vol 289 ◽  
pp. 01006 ◽  
Author(s):  
Alberto Negrini ◽  
Marta Roig-Flores ◽  
Eduardo J. Mezquida-Alcaraz ◽  
Liberato Ferrara ◽  
Pedro Serna
Keyword(s):  
Reinforced Concrete ◽  
Water Permeability ◽  
High Performance ◽  
Water Immersion ◽  
Crack Pattern ◽  
The Self ◽  
Reinforced Concrete Beams ◽  
Multiple Cracks ◽  
Self Healing ◽  
High Performance Fibre

Concrete has a natural self-healing capability to seal small cracks, named autogenous healing, which is mainly produced by continuing hydration and carbonation. This capability is very limited and is activated only when in direct contact with water. High Performance Fibre-Reinforced Concrete and Engineered Cementitious Composites have been reported to heal cracks for low damage levels, due to their crack pattern with multiple cracks and high cement contents. While their superior self-healing behaviour compared to traditional concrete types is frequently assumed, this study aims to have a direct comparison to move a step forward in durability quantification. Reinforced concrete beams made of traditional, high-performance and ultra-high-performance fibre-reinforced concretes were prepared, sized 150×100×750 mm3. These beams were pre-cracked in flexion up to fixed strain levels in the tensioned zone to allow the analysis of the effect of the different cracking patterns on the self-healing capability. Afterwards, water permeability tests were performed before and after healing under water immersion. A modification of the water permeability test was also explored using chlorides to evaluate the potential protection of this healing in chloride-rich environments. The results show the superior durability and self-healing performance of UHPFRC elements.

Alkali Activity of Granite Aggregates and Control in the Concrete of the Three Gorges Project

2013 ◽  
Vol 539 ◽  
pp. 249-254
Author(s):  
Zai Qin Wang ◽  
Chong Xi Liu ◽  
Zi Yun Wen ◽  
Zhen Li ◽  
Liang Xiao
Keyword(s):  
Standardized Test ◽  
Expansion Ratio ◽  
Test Methods ◽  
Observation Time ◽  
Three Gorges Project ◽  
Three Gorges ◽  
Concrete Aggregates ◽  
The Three Gorges ◽  
The Three Gorges Project ◽  
And Control

On the basis of the existing standardized test methods of concrete aggregates alkali activity, the alkali activity of the granite aggregates is studied by extending the observation time. The results showed that the alkali reaction expansion ratio of the fresh granite broke through the 0.1% criterion limit after a decade of time. The reactant microstructure characteristic is similar to the structure of the alkali-silica reaction, the thickness of reaction layer is about 2~4 µm. Controlling the total alkali content of the dam concrete and replacing cement by mixing a certain proportion of fly ash can effectively prevent the occurrence of the AAR in the Three Gorges Project.

scholarly journals Mechanical Recovery of Cracked Fiber-Reinforced Mortar Incorporating Crystalline Admixture, Expansive Agent, and Geomaterial

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Abdul Salam Buller ◽  
Fahad ul Rehman Abro ◽  
Kwang-Myong Lee ◽  
Seung Yup Jang
Keyword(s):  
Water Flow ◽  
Mechanical Performance ◽  
Water Flow Rate ◽  
Self Healing ◽  
Test Results ◽  
Fiber Reinforced ◽  
Dissipation Energy ◽  
Expansive Agent ◽  
Strength Recovery ◽  
Crack Sealing

This research is sought to characterize the stimulated autogenous healing of fiber-reinforced mortars that incorporate healing agents such as crystalline admixtures, expansive agents, and geomaterials. The effects of the healing materials on mechanical performance and water permeability were evaluated experimentally. Furthermore, microscopic and microstructural observations were conducted to investigate the characteristics and physical appearance of healing products within healed cracks. Test results are presented herein regarding index of strength recovery (ISR), index of damage recovery (IDR) and index of dissipation energy gain (IDEG) in relation to crack healing, and reduction of water flow rate. The self-healing capability of the mortars was greater in terms of resisting water flow rather than recovering mechanical performance likely because water flow depends on surface crack sealing, whereas mechanical performance depends on bonding capacity as well as full-depth healing of cracks; thus, mechanical performance may further be improved after longer healing duration.

Novel active crack width control technique to reduce the variation on water permeability results for self-healing concrete

2019 ◽  
Vol 203 ◽  
pp. 541-551 ◽  
Author(s):  
Tim Van Mullem ◽  
Elke Gruyaert ◽  
Brenda Debbaut ◽  
Robby Caspeele ◽  
Nele De Belie
Keyword(s):  
Water Permeability ◽  
Crack Width ◽  
Control Technique ◽  
Self Healing
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