scholarly journals A Study on the Adhesion in the Interfacial Transition Zone Between Glass Fibre Reinforced Rebar and the Cement Matrix

2021 ◽  
Vol 1203 (3) ◽  
pp. 032023
Author(s):  
Grigory Yakovlev ◽  
Zarina Saidova ◽  
Rostislav Drochytka ◽  
Anastasiya Gordina ◽  
Igor Pudov ◽  
...  
Keyword(s):  
Transition Zone ◽  
Interfacial Transition Zone ◽  
Cement Matrix ◽  
Cement Stone ◽  
Hydration Products ◽  
Reinforcing Bar ◽  
Reinforced Polymer ◽  
Structural Density ◽  
Dta Analysis ◽  
Fibre Reinforced Polymer

Abstract This study is aimed at increasing the adhesion of the fibre-reinforced polymer rods to the binder in the cement-based composites in order to eliminate the problem of rod slippage under loading and broaden the application of composite reinforcement in the construction industry. It is assumed that the better adhesion of reinforcement rod to the cement matrix can be provided by increasing the cement stone structural density, and, in particular, by compacting the structure of the hydration products formed on the surface the fibre-reinforced polymer reinforcement rod. Such increase in strength and density can be achieved by adding nanodispersed additives such as metakaolin, the dispersion of carbon black and Peneco Nano Stachema primer into the composition of the cement matrix. Additional adhesion of the cement matrix to the reinforcement is ensured by coating it with the primer, which seals the structure of the cement matrix located in the interfacial transition zone between the reinforcing bar and the cement stone. Experimental study proved that the proposed approach allows the formation of a strong and dense structure in the interfacial transition zone between the cement matrix and the fibre-reinforced polymer reinforcement rod surface. The introduction of metakaolin and a dispersion of technical soot led to an increase in the adhesion strength of fibre-reinforced polymer rod with a cement matrix by 27% and 29%, respectively. The IR spectral analysis and DTA analysis results showed that the mineralogy and morphology of the hydration products was changed due to the addition of the modifying additives, thus improving the adhesion characteristics and corrosion resistance of fibre- reinforced polymer in the cement-based composites.

Interfacial Transition Zone Characteristics of Light-Burnt MgO Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 397-400
Author(s):  
Xia Chen ◽  
Hua Quan Yang ◽  
Yan Shi ◽  
Kai Tao Xiao ◽  
Yu Qiang Lin
Keyword(s):  
Transition Zone ◽  
Interfacial Transition Zone ◽  
Cement Matrix ◽  
Mgo Concrete

The morphology and elements enrichment in the vicinity of interfacial transition zone was investigated with employment of SEM, EDS and BEI. Results indicated that the morphology of products of hydration in ITZ area and cement matrix was similar but differed in amount, size and crystal features. Elements Ca, Si, Al and Mg had tendency to enrich in ITZ zone but differed in accumulation extent in orders. MgO was non-uniformly distributed in concrete, fully mixed in construction though, richer in cement matrix than in ITZ, yet MgO later inclined to migrate to ITZ area and the gap in between was mitigated with in-depth hydration.

Interfacial Transition Zone Meso-Structure of MgO Concrete Loaded to Failure by Computed Tomography

2012 ◽  
Vol 253-255 ◽  
pp. 403-407
Author(s):  
Hua Quan Yang ◽  
Xia Chen ◽  
Yong Zhen Zuo
Keyword(s):  
Computed Tomography ◽  
Transition Zone ◽  
Ultimate Load ◽  
Ct Images ◽  
Interfacial Transition Zone ◽  
Cement Matrix ◽  
Load To Failure ◽  
Mgo Concrete

The computed tomography was introduced to track the development of cracks in cement matrix and interfacial transition zone of MgO concrete under load to failure. Results indicated that some pores were present before concrete was loaded due to none compaction which would tend to initiate cracks expanding. After loading, energy transferring route kept changing and extended towards weak area and it chose to be released through aggregates when concentrated stress on cracks tip surpassed ultimate load with consequences of some cracks getting interconnected with each other through cement matrix. Differentiated and Binarized CT images analysis confirmed that width of cracks was increased and extending routes diversified with loading implemented and interfacial transition zone remained primary choice for cracks development.

Influence of Interfacial Transition Zone on Local and Overall Fracture Response of Cementitious Composites

2018 ◽  
Vol 784 ◽  
pp. 97-102 ◽  
Author(s):  
Vojtěch Zacharda ◽  
Jiří Němeček ◽  
Hana Šimonová ◽  
Barbara Kucharczyková ◽  
Michal Vyhlídal ◽  
...  
Keyword(s):  
Transition Zone ◽  
Interfacial Transition Zone ◽  
Cement Matrix ◽  
Mechanical Fracture ◽  
Three Point Bending ◽  
Fine Grained ◽  
Bulk Matrix ◽  
Electron Microscopes ◽  
Microstructure Measurements ◽  
Good Agreement

Mechanical fracture properties of interfacial transition zone (ITZ) of fine-grained composite based on cement matrix with different types – basalt, granite, marble and amphibolite – of rock inclusion were studied. Specimens with the initial stress concentrator were tested in standard three-point bending configuration. Fracture surfaces were examined with light and electron microscopes. Local ITZ response was characterized by nanoindentation in the vicinity of rock inclusions. Local elasticity, hardness and viscous properties were assessed. It has been shown that the ITZ is mechanically weaker compared to the bulk matrix in the region of ca. 0–20 μm from the inclusion for all specimen’s types. It exhibits gradual increase of elastic modulus and hardness, which can be approximately expressed by a power law. On the other hand, the creep in ITZ was found to be higher compared to the bulk matrix. The results of nanoindentation measurements are in a good agreement with overall mechanical properties, fracture response and microstructure measurements done by scanning electron microscopy.

Perlite Concrete Based on Alkali Activated Cements

2014 ◽  
Vol 897 ◽  
pp. 280-283
Author(s):  
Vít Petranek ◽  
Pavel Krivenko ◽  
Оleg Petropavlovsky ◽  
Sergii Guzii
Keyword(s):  
Transition Zone ◽  
Heat Insulation ◽  
Interfacial Transition Zone ◽  
Cement Stone ◽  
High Durability ◽  
Alkali Activated

The use of the alkali activated cements for the manufacture of perlite concrete pressed and vibro-pressed products for heat insulation intended for various purposes was studied. The interfacial transition zone perlite grain cement stone was examined in order to reveal features of its formation. These features allow to create a dense and strong shell/caging around the perlite grain which helps to avoid its corrosion and produce perlite concretes with high durability.

Nanomechanical Performance of Interfacial Transition Zone in Fiber Reinforced Cement Matrix

2018 ◽  
Vol 760 ◽  
pp. 251-256 ◽  
Author(s):  
Vojtěch Zacharda ◽  
Petr Štemberk ◽  
Jiří Němeček
Keyword(s):  
Elastic Modulus ◽  
Transition Zone ◽  
Cement Paste ◽  
Steel Fiber ◽  
Mechanical Performance ◽  
Creep Compliance ◽  
Interfacial Transition Zone ◽  
Cement Matrix ◽  
Average Value ◽  
Reinforced Cement

This paper shows a micromechanical study of interfacial transition zone (ITZ) around steel fiber in cement paste. It investigates microstructure and mechanical performance of the ITZ by a combination of nanoindentation and scanning electron microscopy (SEM). The investigated specimens were made from cement CEM I 42.5R paste with dispersed reinforcement in the form of steel fiber TriTreg 50 mm. The SEM demonstrated larger porosity and smaller portion of clinkers in the ITZ. Nanoindentation delivered values of elastic modulus, hardness and creep parameters around the fiber. An average value of elastic modulus in ITZ was at the level of 67% in comparison with cement bulk and the width of ITZ was about 40 µm. The value of hardness was found to be 60% of the average hardness of the bulk cement paste. The measured load-displacement curves were used for calculation of creep indentation parameter (CIT) and the creep compliance function. An average value of the creep compliance in the ITZ was found to be two times higher than in the cement bulk.

An Investigation on the Interfacial Transition Zone in Concrete Using SEM

2012 ◽  
Vol 446-449 ◽  
pp. 166-170
Author(s):  
Hsi Chi Yang ◽  
Miao Ying Cheng ◽  
Jung Pin Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transition Zone ◽  
Calcium Ion ◽  
Test Specimen ◽  
Interfacial Transition Zone ◽  
Small Samples ◽  
Hydration Products ◽  
Compressive Test ◽  
Scanning Electron

The technique of linking the SEM (Scanning Electron Microscopy) photographs taken around the interfacial transition zone area is applied to observe the development of hydration products for aggregate and paste at the different curing ages. This research first chooses the aggregate with clay properties not containing the calcium ion, and then observes the hydration products (such as CH, C-S-H) of calcium ion on the aggregate. Finally it assesses if the aggregate will produce ion exchange with cement and generate the hydration products. The very small samples to be observed are taken from the concrete compressive test specimen and must include both aggregate and paste. They are wiped with alcohol to have better pictures before shooting SEM. Initially, the interface of aggregate and paste is sought using 2000x magnification. However, the hydration products on either side of the interface with a range of 50 μm are observed using 10000x magnification. From the results, it is found that aggregate has not interacted with cement paste to produce hydration products and the bond stress of aggregate and paste is controlled by hydration products of paste.

scholarly journals The Effect of Interfacial Transition Zone Properties on the Elastic Properties of Cementitious Nanocomposite Materials

2015 ◽  
Vol 2015 ◽  
pp. 1-13
Author(s):  
Ala G. Abu Taqa ◽  
Rashid K. Abu Al-Rub ◽  
Ahmed Senouci ◽  
Nasser Al-Nuaimi ◽  
Khaldoon A. Bani-Hani
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Elastic Modulus ◽  
Transition Zone ◽  
Parametric Study ◽  
Nanocomposite Materials ◽  
Interfacial Transition Zone ◽  
Cement Matrix ◽  
Reinforced Cement ◽  
Cohesive Surface

A parametric study was conducted to explore the effect of the interfacial transition zone (ITZ or interphase) on the overall elastic modulus of the CNT-reinforced cement. The effect of the ITZ properties on the elastic modulus of the CNT-reinforced cement was investigated using a four-phase axisymmetric model consisting of a single CNT aligned at the center of composite unit cell, an interface, an ITZ (or interphase), and a cement matrix. The CNT and cement matrix were assumed fully elastic while the interface was modeled using a cohesive surface framework. The width and mechanical properties of the ITZ and the interface were found to affect significantly the elastic modulus and the behavior of the composite material.

Influence and Mechanisms of In Situ Toughening Telechelic Polymer on the Microstructure of Concrete

2013 ◽  
Vol 539 ◽  
pp. 259-265
Author(s):  
Xiao Bin Zhu ◽  
Pan Feng ◽  
Jia Ping Liu ◽  
Bei Ding ◽  
Jin Xiang Hong
Keyword(s):  
Transition Zone ◽  
Cement Paste ◽  
Film Formation ◽  
Indentation Test ◽  
Interfacial Transition Zone ◽  
Hydration Products ◽  
Dense Area ◽  
Mutation Pattern ◽  
Micro Structures

To find out the toughening mechanism of in-situ toughening telechelic polymers (ITTP) in concrete, SEM & EDS and Nano indenter were used to research the variation of concrete hydration products and the interfacial transition zone between the cement paste and aggregate. The results indicate that the toughening effect of ITTP is not carried out by film formation. And the proportion of LD C-S-H in cement hydration products increased significantly and the CH content decreased after introducing the ITTP into concrete. Nano indentation test results show that the non-dense area ratio of ITZ decreased, and the CH content in ITZ increased slightly. The Ca/Si blurred from mutation pattern with decreasing the distance to aggregate surface in the region of interfacial transition zone between aggregate and cement paste, and the thickness of ITZ increased. The conclusions show that the ITZ and hydration products are both key micro-structures which affect the toughness of concrete, and it provides us some guidance for realizing concrete toughness ascension through microstructure adjustment.

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