Micro-Scale Fracture Properties of Cementitious Composites

Kód výsledku v IS VaVaI

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Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Micro-Scale Fracture Properties of Cementitious Composites

Popis výsledku v původním jazyce

This book is focused on the experimental investigation of fracture and related mechanical properties of cementitious composites at micro-level. The measured data are used for a better understanding of microstructure, detailed mechanical characterization of micro-scale material phases and as an input for multi-scale models, which can predict macroscopic mechanical properties. Characterization of mechanical properties (Young's modulus, hardness, creep) of individual hydration products is possible due to advanced experimental technique, nanoindentation. Recently a new nanoindentation mode accelerated property mapping (XPM) was designed to access local mechanical properties map in a few minutes. The mode was compared to standard nanoindentation techniques. Fracture properties (tensile strength and fracture energy) on a micrometer scale were measured for individual hydration products of pure cement paste and for the first time for silica fume blended cement paste and for main reaction products of alkali-activated fly-ash. The experiments were performed on the 14-20 µm long micro-cantilever beams, fabricated by Focused Ion Beam (FIB). Similar values of tensile strength were found for the outer product (~260 MPa) and inner product (~700 MPa) of pure and blended cement pastes. Additionally, the tensile strength of N-A-S-H gel (~340 MPa) was found to be mechanically comparable with the outer product. Moreover, the effects of a high vacuum and FIB milling were studied. The scratch test was used as another technique to access fracture toughness of individual hydration products cement paste. The scratch tests were supported by techniques like Scanning Electron Microscopy and nondestructive acoustic emission method. The fracture toughness results correspond well with micro-cantilever bending results. Lastly, two initial experiments providing preliminary data of multiple phase testing were performed to find the source of the rapid decrease of mechanical properties from micro-scale to meso-scale.

Název v anglickém jazyce

Micro-Scale Fracture Properties of Cementitious Composites

Popis výsledku anglicky

This book is focused on the experimental investigation of fracture and related mechanical properties of cementitious composites at micro-level. The measured data are used for a better understanding of microstructure, detailed mechanical characterization of micro-scale material phases and as an input for multi-scale models, which can predict macroscopic mechanical properties. Characterization of mechanical properties (Young's modulus, hardness, creep) of individual hydration products is possible due to advanced experimental technique, nanoindentation. Recently a new nanoindentation mode accelerated property mapping (XPM) was designed to access local mechanical properties map in a few minutes. The mode was compared to standard nanoindentation techniques. Fracture properties (tensile strength and fracture energy) on a micrometer scale were measured for individual hydration products of pure cement paste and for the first time for silica fume blended cement paste and for main reaction products of alkali-activated fly-ash. The experiments were performed on the 14-20 µm long micro-cantilever beams, fabricated by Focused Ion Beam (FIB). Similar values of tensile strength were found for the outer product (~260 MPa) and inner product (~700 MPa) of pure and blended cement pastes. Additionally, the tensile strength of N-A-S-H gel (~340 MPa) was found to be mechanically comparable with the outer product. Moreover, the effects of a high vacuum and FIB milling were studied. The scratch test was used as another technique to access fracture toughness of individual hydration products cement paste. The scratch tests were supported by techniques like Scanning Electron Microscopy and nondestructive acoustic emission method. The fracture toughness results correspond well with micro-cantilever bending results. Lastly, two initial experiments providing preliminary data of multiple phase testing were performed to find the source of the rapid decrease of mechanical properties from micro-scale to meso-scale.

Druh

B - Odborná kniha

CEP obor

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OECD FORD obor

20101 - Civil engineering

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

ISBN

978-80-01-07241-7

Počet stran knihy

134

Název nakladatele

ČVUT v Praze, Fakulta stavební

Místo vydání

Praha

Kód UT WoS knihy

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