Nanoscale characterization of engineered cementitious composites (ECC)

Sakulich, Aaron R.; Li, Victor C.

doi:10.1016/j.cemconres.2010.11.001

Cited by 132 publications

(54 citation statements)

References 19 publications

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“…Although the technique is very useful, this method has certain limitations, especially for heterogeneous materials such as cementitious ones. These tests are very sensitive to the surface preparation (Trtik et al 2009;Sakulich and Li 2011), as it directly influences the results and reliability of the obtained data. As a consequence, mechanical values obtained by various investigators have a wide variation range.…”

Section: Introductionmentioning

confidence: 99%

“…From the indentation load and displacement measurements, hardness and E modulus of the indented volume are calculated. Indentation tests have been used by a number of researchers: Sakulich and Li (2011) measured mechanical properties of matrix-fibre interface, Zhu and Bartos (1997) used the microindentation method to measure the properties of the interfacial area in aged glass fibre reinforced cement, Wang et al (2009) for interfacial area in steel fibre reinforced mortar and Xiao et al (2013) were studying the interfacial transition zones in recycled aggregate concrete. Although the technique is very useful, this method has certain limitations, especially for heterogeneous materials such as cementitious ones.…”

Section: Introductionmentioning

confidence: 99%

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Micromechanical Study of the Interface Properties in Concrete Repair Systems

Luković

Šavija

Dong

et al. 2014

ACT

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Micromechanical interface properties in a concrete repair system determine the performance and reliability of a repaired structure. In order to characterize these properties, nanoindentation technique was applied. Three different repair material mixtures, based on Portland cement or partial replacement of Portland cement with blast furnace slag, were tested. Hardness and elastic modulus values obtained from the nanoindentation were used directly as input for simulated direct tension test. This way, the fracture behaviour of original microstructure, "mimicked" by Delft lattice model, is analysed. Backscattered electron (BSE) image analysis is utilized to estimate the average size of the interface zone which is distinguished as locally more porous area. This, together with simulation results, is further used for calculation of the interface stiffness. Simulation results enable prediction and better insight into fracture propagation and micromechanical response of the tested zone. They also indicate the ratio between interface and bulk material fracture properties when different types of repair materials are used. Load displacement diagrams of interface, old and new material can serve as an input for numerical modelling and understanding of fracture behaviour of the repair systems at the higher scale. Potentially, this approach may develop as a tool for verifying and engineering interface properties such that desired performance of the repaired structure is achieved.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Micromechanical Study of the Interface Properties in Concrete Repair Systems

Luković

Šavija

Dong

et al. 2014

ACT

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“…The higher porosity of the ITZ can significantly reduce the mechanical properties and durability of cementitious mixtures by allowing easier penetration of aggressive species into the mixtures [9]. Recently, nanoindentation which is a useful tool to derive the local nanomechanical properties of the materials, has been widely used to directly characterize the nanomechanical properties of the interphase region [10][11][12][13][14][15][16]. Although there are a lot of studies which have investigated the microstructure and mechanical properties of interphase region in PCC, studies on investigating chemical properties and integrating with mechanical and microstructural features of this region are limited.…”

Section: Introductionmentioning

confidence: 99%

An integrated microstructural-nanomechanical-chemical approach to examine material-specific characteristics of cementitious interphase regions

Khedmati

Kim

Turner

et al. 2018

Materials Characterization

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Abstract:Effective properties and structural performance of cementitious mixtures are substantially governed by the quality of the interphase region because it acts as a bridge transferring forces between aggregates and a binding matrix and is generally susceptible to damage. As alternative binding agents like alkali-activated precursors have obtained substantial attention in recent years, there is a growing need for fundamental knowledge to uncover interphase formation ACCEPTED MANUSCRIPTA C C E P T E D M A N U S C R I P T mechanisms. In this paper, two different types of binding materials, i.e., fly ash-based geopolymer and ordinary portland cement, were mixed with limestone aggregate to examine and compare the microstructures and nanomechanical properties of interphase region. To this end, microstructural characteristics using scanning microscopies, nanomechanical properties by nanoindentation tests, and spatial mapping of chemical contents based on the energy dispersive spectroscopy were integrated to identify and investigate the interphase region formed by the case-specific interactions between the matrix materials and limestone. The integrated microstructural-nanomechanicalchemical approach was effective to better understand links between material-specific properties of cementing phases. More specifically, the fly ash-based geopolymer paste was usually well bonded to the aggregate surface with a rich formation of N-A-S-H gel, while interfacial debonding was often observed between aggregate surface and paste in ordinary portland cement concrete. However, when a good bonding between aggregate and paste is formed, interphase region in PCC didn't show any considerable difference in nanomechanical properties compared to the bulk paste. ACCEPTED MANUSCRIPT A C C E P T E D M A N U S C R I P T An Integrated Microstructural-Nanomechanical-Chemical Approach to Examine MaterialSpecific Characteristics of Cementitious Interphase Regions Abstract:Effective properties and structural performance of cementitious mixtures are substantially governed by the quality of the interphase region because it acts as a bridge transferring forces between aggregates and a binding matrix and is generally susceptible to damage. As alternative binding agents like alkali-activated precursors have obtained substantial attention in recent years, there is a growing need for fundamental knowledge to uncover interphase formation mechanisms. In this paper, two different types of binding materials, i.e., fly ash-based geopolymer and ordinary portland cement, were mixed with limestone aggregate to examine and compare the microstructures and nanomechanical properties of interphase region. To this end, microstructural characteristics using scanning microscopies, nanomechanical properties by nanoindentation tests, and spatial mapping of chemical contents based on the energy dispersive spectroscopy were integrated to identify and investigate the interphase region formed by the case-specific interactions between the matrix materials and limestone. The...

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“…This work builds upon previous research [1,[11][12][13][14][15][16][17][18][19][20][21][22][23][24] that focused on nanomechanical methods for characterizing cementitious materials.…”

Section: Accepted Manuscriptmentioning

confidence: 98%