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.

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.

scholarly journals The Effect of Fiber Geometry and Interfacial Properties on the Elastic Properties of Cementitious Nanocomposite Material

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Ala G. Abu Taqa ◽  
Rashid K. Abu Al-Rub ◽  
Ahmed Senouci ◽  
Nasser Al-Nuaimi ◽  
Khaldoon A. Bani-Hani
Keyword(s):  
Elastic Modulus ◽  
Cement Paste ◽  
Parametric Study ◽  
3D Model ◽  
3D Models ◽  
Cement Matrix ◽  
Fiber Waviness ◽  
Axisymmetric Model ◽  
Three Phase ◽  
Reinforced Cement

This paper investigates the elastic (Young’s) modulus of carbon Nanotube- (CNT-) reinforced cement paste using 3D and axisymmetric models using Abaqus software. The behavior of the CNT and the cement matrix was assumed to be fully elastic while the cohesive surface framework was used to model the interface. To investigate the effect of fiber waviness on the value of the elastic modulus, 3D models were developed assuming different distributions of fibers. The results obtained using the 3D model were compared to those obtained using the simplified three-phase axisymmetric model which consists of one single CNT aligned in the center of composite unit cell, an interface, and cement matrix. A parametric study was then carried out using the axisymmetric model to study the role of the interface in the composite elastic modulus without accounting for the presence of the interfacial transition zone (ITZ or interphase). The results showed that the CNTs waviness significantly reduced their reinforcing capability in the cement paste. On the other hand, the results obtained using the axisymmetric model were found to be in good agreement with those obtained using the 3D model. Moreover, the results of the parametric study showed that the interface properties significantly affect the composite elastic modulus and alter its behavior.

scholarly journals Effect of water/cement ratio on micro-nanomechanical properties of the interface between cementitious matrix and steel microfibers in ultra-high performance cementitious composites

2021 ◽  
Vol 14 (4) ◽  
Author(s):  
Vanessa Fernandes Cesari ◽  
Fernando Pelisser ◽  
Philippe Jean Paul Gleize ◽  
Milton Domingos Michel
Keyword(s):  
Transition Zone ◽  
Cement Paste ◽  
Calcium Silicate ◽  
High Performance ◽  
Calcium Silicate Hydrate ◽  
Interfacial Transition Zone ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Nanomechanical Properties ◽  
Cementitious Matrix

abstract: Ultra-high performance concretes with steel microfibers have been studied in depth with the aim of producing more efficient and durable structures. The performance of these materials depends on the characteristics of the interface between microfibers and cementitious matrix. This research investigates the micro-nanomechanical properties of the interfacial transition zone between the steel microfibers and the matrix of ultra-high performance cementitious composite. The effect of the water/cement ratio and distance from the microfiber were analyzed. The results confirm the formation of high-density calcium-silicate-hydrate (HD C-S-H) matrix at higher concentrations than low-density calcium-silicate-hydrate (LD C-S-H) for w/c ratios of 0.2 and 0.3. The properties in cementitious matrix interface with steel microfibers were very similar to that measured for the cement paste, and no significant difference was observed regarding the distance to the microfibers in relation to the elastic modulus, hardness and chemical composition. Thus, the authors can conclude that the formation of a less resistant region does not occur at the interfacial transition zone cement paste/microfibers.

Experimental Study of Diffusivity of the Interfacial Transition Zone between Cement Paste and Aggregate

2016 ◽  
Vol 28 (10) ◽  
pp. 04016109 ◽  
Author(s):  
Zhilu Jiang ◽  
Qinghua Huang ◽  
Yunping Xi ◽  
Xianglin Gu ◽  
Weiping Zhang
Keyword(s):  
Experimental Study ◽  
Transition Zone ◽  
Cement Paste ◽  
Interfacial Transition Zone
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