Temperature Effects on Local Structure, Phase Transformation, and Mechanical Properties of Calcium Silicate Hydrates

2021 ◽  
Author(s):  
Sumin Im ◽  
Hyeonseok Jee ◽  
Heongwon Suh ◽  
Manabu Kanematsu ◽  
Satoshi Morooka ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Local Structure ◽  
Calcium Silicate ◽  
Temperature Effects ◽  
Calcium Silicate Hydrates ◽  
Structure Phase

scholarly journals Microstructural characteristics of ultra-high performance concrete by grid nanoindentation and statistical analysis

2021 ◽  
Vol 15 (1) ◽  
pp. 90-101
Author(s):  
Pham Thai Hoan ◽  
Ngo Tri Thuong
Keyword(s):  
Mechanical Properties ◽  
Statistical Analysis ◽  
Calcium Silicate ◽  
High Performance ◽  
High Performance Concrete ◽  
Cement Clinker ◽  
Indentation Modulus ◽  
Ultra High Performance Concrete ◽  
Deconvolution Analysis ◽  
Calcium Silicate Hydrates

In this study, grid nanoindentation and statistical deconvolution analysis were applied into a developed Ultra-high performance concrete (UHPC) to broaden the understanding of the microstructure phases and their mechanical properties. A total of 550 nanoindentation tests was carried out on UHPC and the mechanical properties, including indentation modulus and hardness of the indented material were extracted from nanoindentation load-depth curves. The statistical deconvolution analysis was then utilized to analyze the modulus and hardness spectra. The experimental and analysis results revealed that the modulus and hardness data obtained from nanoindentation tests can be used in the accurate and reliable identification of the microstructure phases and their properties in UHPC. For the present UHPC, the microstructure can be characterized into 6 phases with distinguishable mechanical properties, including micro porosity, Low Density Calcium Silicate Hydrates (LD CSH), High Density Calcium Silicate Hydrates (HD CSH), silica powder and sand, and residual cement clinker. The obtained modulus and hardness values of these phases were in the range of various reported ones for cement-based materials and UHPC. Keywords: ultra-high performance concrete; microstructures; micromechanical properties; nanoindentation; statistical analysis.

Disclosing the Mechanical Properties of Green Calcium-Silicate-Hydrates by Statistical Nanoindentation Techniques

2011 ◽  
Vol 409 ◽  
pp. 544-549 ◽  
Author(s):  
Luca Sorelli ◽  
Daniel Vallée ◽  
Aali R. Alizadeh ◽  
James Beaudoin ◽  
Nicholas Randall
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Statistical Analysis ◽  
Calcium Silicate ◽  
Layer Structure ◽  
Cement Industry ◽  
Stoichiometric Ratio ◽  
New Class ◽  
Preliminary Work ◽  
Calcium Silicate Hydrates

In order to reduce CO2emissions, the cement industry has developed a new class cements. The Calcium-Silicate-Hydrates (CSH) that form are generally characterized by a low stoichiometric ratio for CaO and SiO2. This low C/S ratio affects the C-S-H layer structure and has a significant effect on the mechanical properties. This work exploits a novel statistical nanoindentation technique (SNT) to study the effect of the C/S ratio on the mechanical properties of synthetic CSH. Different CSH types were prepared by varying the C/S ratio of the starting materials. After undertaking a grid nanoindentation approach for each sample, the statistical analysis allowed extracting the mechanical properties, such as elastic modulus, hardness and creep. The results of this preliminary work shed new light on the implications of C-S-H stoichiometry on mechanical properties.

scholarly journals Nature of Interatomic Bonding in Controlling the Mechanical Properties of Calcium Silicate Hydrates

2016 ◽  
Vol 99 (6) ◽  
pp. 2120-2130 ◽  
Author(s):  
Chamila Dharmawardhana ◽  
Morayo Bakare ◽  
Anil Misra ◽  
Wai‐Yim Ching
Keyword(s):  
Mechanical Properties ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrates ◽  
Interatomic Bonding

scholarly journals Mechanical properties of calcium silicate hydrates

2010 ◽  
Vol 44 (1) ◽  
pp. 13-28 ◽  
Author(s):  
Rouhollah Alizadeh ◽  
James J. Beaudoin ◽  
Laila Raki
Keyword(s):  
Mechanical Properties ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrates

Research on the Preparation of Carbon Fiber Reinforced Calcium Silicate Hydrates Insulating Material

2014 ◽  
Vol 711 ◽  
pp. 158-161
Author(s):  
Xia Zhang ◽  
Cong Ke Wang ◽  
Rui Zhang ◽  
Chuan Wei Du ◽  
Guo Zhong Li
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Calcium Silicate ◽  
Average Diameter ◽  
Insulation Material ◽  
Micro Structure ◽  
Insulating Material ◽  
Calcium Silicate Hydrates ◽  
The Matrix ◽  
Scanning Electron

In this article, the influence of the churning technology on the average diameter of xonotlite particle and the micro-structure of xonotlite particle during the hydrothermal synthesis progress of the heat insulating material of xonotlite were researched. The influence of fiber adding process on the strength and density of calcium silicate insulation material was studied. The complexity and the macro mechanical properties of the fiber dispersed in the matrix with different fiber adding way were discussed. The microstructure of xonotlite was observed and analyzed by scanning electron microscope and the related mechanisms were studied.

Micro-Mechanical Properties of Individual Phases in Cement Pastes under Brine Solution Using Nanoindentation and Scanning Electron Microscopy

2017 ◽  
Vol 46 ◽  
pp. 31-44 ◽  
Author(s):  
Yue Li ◽  
Wang Peng ◽  
Zhong Zheng Guan ◽  
Qing Jun Ding
Keyword(s):  
Mechanical Properties ◽  
Cement Paste ◽  
Calcium Silicate ◽  
Saline Lake ◽  
Western China ◽  
Indentation Modulus ◽  
Cement Pastes ◽  
Brine Solution ◽  
Calcium Silicate Hydrates ◽  
Scanning Electron

Understanding the micro-mechanical properties and the microstructure of cement-based materials under the saline lake environment in western China can provide a scientific basis for the durability design. In this study, cement pastes ((w/c=0.35) and (w/c=0.53)) were prepared and soaked in brine solution to carry out the dry-wet cycle test, the chemical composition of which is similar to saline lake solution. The micrographs of corroded regions and corrosion products were observed and analyzed under scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). Micro-mechanical properties of different phases were tested by nanoindentation, and multi-peaks fitting was carried out for the experimental frequency distributions of the indentation modulus and indentation hardness by Gaussian function. In the meantime,the statistical distribution of micro-mechanical properties was summarized for the hydrates in corroded cement paste, which has included the low density calcium–silicate–hydrates (LD C-S-H gel), high density calcium–silicate–hydrates (HD C-S-H gel) and calcium hydroxide (CH). The results show that micro mechanical properties of each phase in cement paste after brine corrosion decreased significantly. In addition, the water-cement ratio has little effect on the micro mechanical properties, but much effect on volume fraction of each phase.

scholarly journals Structure, Fractality, Mechanics and Durability of Calcium Silicate Hydrates

2021 ◽  
Vol 5 (2) ◽  
pp. 47
Author(s):  
Shengwen Tang ◽  
Yang Wang ◽  
Zhicheng Geng ◽  
Xiaofei Xu ◽  
Wenzhi Yu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cement Paste ◽  
Calcium Silicate ◽  
Preparation Method ◽  
Point Of View ◽  
Computational Point ◽  
Calcium Silicate Hydrates ◽  
Binding Phase ◽  
Cement Based Materials ◽  
Hydrated Products

Cement-based materials are widely utilized in infrastructure. The main product of hydrated products of cement-based materials is calcium silicate hydrate (C-S-H) gels that are considered as the binding phase of cement paste. C-S-H gels in Portland cement paste account for 60–70% of hydrated products by volume, which has profound influence on the mechanical properties and durability of cement-based materials. The preparation method of C-S-H gels has been well documented, but the quality of the prepared C-S-H affects experimental results; therefore, this review studies the preparation method of C-S-H under different conditions and materials. The progress related to C-S-H microstructure is explored from the theoretical and computational point of view. The fractality of C-S-H is discussed. An evaluation of the mechanical properties of C-S-H has also been included in this review. Finally, there is a discussion of the durability of C-S-H, with special reference to the carbonization and chloride/sulfate attacks.

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