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 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.

Evaluating Mechanical Properties of Cement Materials by Depth-Sensing Indentation Method

2010 ◽  
Vol 44-47 ◽  
pp. 2587-2591
Author(s):  
Xiu Fang Wang ◽  
Yi Wang Bao ◽  
Kun Ming Li ◽  
Yan Qiu ◽  
Xiao Gen Liu
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Energy Dissipation ◽  
Engineering Application ◽  
Calculated Data ◽  
Absorption Capacity ◽  
Cement Industry ◽  
Depth Sensing ◽  
Indentation Method ◽  
Recovery Resistance

The energy consumption of crushing is directly affected by the mechanical properties of cement materials. The elastic modulus, energy dissipation, recovery resistance and other mechanical properties of cement materials are evaluated based on the depth-sensing indentation method in this work. It is significant and efficient for engineering application. In results, the calculated elastic modulus is close to that measured by dynamic method, being used to verify the correctness of the calculated data. And the calculated energy dissipation of clinker is higher than that of limestone and granite, which can partially be used to explain why the grinding of clinker consumes a lot of energy in cement industry. The recovery resistance of clinker is almost identical to that of granite, more than that of limestone. It is found that the clinker, in contrast to granite and limestone, exhibits better plasticity and greater energy absorption capacity.

STRUCTURES AND MECHANICAL PROPERTIES OF MODULATED ZrB2/W AND ZrB2/WNx NANOMULTILAYERS

2010 ◽  
Vol 24 (01n02) ◽  
pp. 34-42 ◽  
Author(s):  
M. TAN ◽  
D. J. LI ◽  
G. Q. LIU ◽  
L. DONG ◽  
X. Y. DENG ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Significant Contribution ◽  
Layer Structure ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Composition Modulation ◽  
Ion Beam Assisted Deposition ◽  
Xrd Patterns

ZrB 2, W , WN x coatings and ZrB 2/ W , ZrB 2/ WN x multilayered coatings have been synthesized by ion beam assisted deposition at room temperature. X-ray diffraction (XRD), XP-2 surface profiler, scanning electron microscopy (SEM) and nano indenter were employed to investigate the influence of modulation periods and N + beam bombardment on microstructure and mechanical properties of the coatings. The low-angle XRD patterns and cross-sectional SEM indicate a well-defined composition modulation and layer structure of the multilayers. The multilayers with modulation periods ranging from 9 to 16 nm without N + bombardment possessed higher hardness and elastic modulus than the rule-of-mixtures value of monolithic ZrB 2 and W coatings. The highest hardness was 24 GPa. N + bombardment to growing multilayers gave a significant contribution to mechanical property enhancement. When modulation period is 9.6 nm, ZrB 2/ WN x multilayer with 200 eV N + bombardment reveals the highest hardness (30.2 GPa) and elastic modulus. This hardest multilayer also showed the improved residual stress and fracture resistance.

Drying of calcium-silicate-hydrates: regeneration of elastic modulus

2015 ◽  
Vol 27 (8) ◽  
pp. 470-476
Author(s):  
P. Pourbeik ◽  
L. Raki ◽  
R. Alizadeh ◽  
J. J. Beaudoin
Keyword(s):  
Elastic Modulus ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrates

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.

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