Evaluating Micro-Structure, Hydration and Thermal Expansions of Cement Containing Nano-Silica

GIS Business ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 158-165 ◽  
Author(s):  
Dr. Sarvesh PS Rajput
Keyword(s):  
Portland Cement ◽  
Mechanical Characteristics ◽  
Microstructural Properties ◽  
Nano Silica ◽  
Micro Structure ◽  
Microstructural Characteristics ◽  
Mechanical And Microstructural Properties

This study reported that the addition of nano-silica enhances the mechanical characteristics of concrete as its compressive, flexural and tensile split strengths are increased. As a comparison mixture to equate it along with nano-modified concrete, ordinary samples of Portland cement (OPC) have been utilized. Herein, upto 6.0 percent of OPC has been substituted by nanosilica. In fact, the introduction of nanosilica improves mechanical and microstructural characteristics of concrete by significantly (28 to 35%). The finding therefore, indicated that partly replacing OPC with up to 5 percent nanosilica increases the mechanical and microstructural properties cured up to ninety days as opposed to the standard OPC mix.

Effect of Boron Carbide Addition on the Physical, Mechanical and Microstructural Properties of Portland Cement Concrete

2011 ◽  
Vol 11 (22) ◽  
pp. 3738-3743 ◽  
Author(s):  
Fatin Nabilah Tajul Arif ◽  
Yusof Abdullah ◽  
Roslinda Shamsudin ◽  
Roszilah Hamid ◽  
Sahrim Haji Ahmad
Keyword(s):  
Portland Cement ◽  
Boron Carbide ◽  
Microstructural Properties ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Mechanical And Microstructural Properties

scholarly journals Microstructural characteristics of mortars prepared by hot lime mix

2020 ◽  
Vol 72 (11) ◽  
pp. 991-1000
Keyword(s):  
Mechanical Properties ◽  
Preparation Method ◽  
Microstructural Properties ◽  
Microstructural Characteristics ◽  
Spongy Texture ◽  
Porous Microstructure ◽  
Mechanical And Microstructural Properties

The effect of lime characteristics and hot lime mix method on hydraulic, microstructural and mechanical properties of mortars is determined by producing mortars from quicklimes of two different marbles and two limestones. Results of SEM-EDS, XRD and TGA analyses reveal that the porous microstructure of mortars and spongy texture of calcite crystals are the indicators of the hot lime mix method. This study shows that characteristics of limestones used for the production of limes, as well as the preparation method, directly affect hydraulic, mechanical and microstructural properties of mortars.

Effects of cellulose nanocrystals as extender on physical and mechanical properties of wood cement composite panels

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8291-8302
Author(s):  
Mona Shayestehkia ◽  
Habibollah Khademieslam ◽  
Behzad Bazyar ◽  
Hossein Rangavar ◽  
Hamid Reza Taghiyari
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Dry Weight ◽  
Cement Composite ◽  
Composite Panels ◽  
Microstructural Properties ◽  
Micro Structure ◽  
Mechanical And Microstructural Properties ◽  
Scanning Electron

The effects of cellulose nanocrystal (CNC) particles were investigated relative to the physical, mechanical, and microstructural properties of wood cement composite panels. Wood and cement were mixed at three ratios of 1:3, 1:3.5, and 1:4. Calcium chloride was added at 3 and 5%. CNC was added to the mixture at five levels (0, 0.1, 0.2, 0.5, and 1%, based on dry weight of cement). The results showed that CNC content of 0.5% had the best impact on the properties. The overall trend showed that with the addition of CNC, tensile, flexural, and physical properties of the composites were considerably enhanced. Scanning electron microscopy demonstrated that the addition of CNC was associated with an improved integrity in the micro-structure of panels.

scholarly journals Investigating the Effects of Polyaluminum Chloride on the Properties of Ordinary Portland Cement

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3290
Author(s):  
Taewan Kim ◽  
Choonghyun Kang ◽  
Sungnam Hong ◽  
Ki-Young Seo
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Chloride Ions ◽  
Aluminum Silicate ◽  
Microstructural Properties ◽  
Sem Images ◽  
Polyaluminum Chloride ◽  
Friedel’S Salt ◽  
Mechanical And Microstructural Properties

This study investigates the mechanical and microstructural properties of paste comprising ordinary Portland cement (OPC) added with polyaluminum chloride (PACl). The properties of the resulting mixture are analyzed using compressive strength, X-ray diffraction, scanning electron microscopy (SEM), mercury intrusion porosimetry, and thermogravimetric analysis. The results show that the addition of PACl improves the mechanical properties of OPC paste, that calcium-(aluminum)-silicate-hydrate (C-(A)-S-H) gel and Friedel’s salt are the major products forming from the reaction with the aluminum and chloride ions in PACl, and that the portlandite content decreases. Moreover, the size and number of micropores decrease, and compressive strength increases. All these phenomena are amplified by increasing PACl content. SEM images confirm these findings by revealing Friedel’s salt in the micropores. Thus, this work confirms that adding PACl to OPC results in a mixture with superior mechanical and microstructural properties.

scholarly journals Enhanced Mechanical and Microstructural Properties of Portland Cement Composites Modified with Submicron Metakaolin

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yaoyu Wang ◽  
Jiye Li ◽  
Lihan Jiang ◽  
Lihua Zhao
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Pore Structure ◽  
Hardened Cement ◽  
Microstructural Properties ◽  
Cement Slurry ◽  
Curing Period ◽  
Practical Engineering ◽  
Mechanical And Microstructural Properties

This work aims to study the influence of submicron metakaolin (SMK) on the mechanical strength, pore structure, and microstructural properties of hardened cement-based slurry (HCS). Portland cement was replaced by SMK at a proportion of 1, 3, 5, and 7 wt%. The compressive strength and flexural strength of the HCS samples were tested at a curing period of 3, 7, 14, and 28 days, and the pore structure of the specimens was analyzed by mercury intrusion porosimetry (MIP) at a curing period of 3 and 28 days. The microstructure characteristics of the hardened samples were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Thermogravimetric analysis (TGA) was also employed to analyze the change in the chemical composition of the HCS. The results showed that the SMK could accelerate the hydration rate of the cement and could improve the mechanical properties of the HCS; the compressive strength and flexural strength of the HCS samples were remarkably enhanced, compared to those of the plain cement, by 67 and 46%, respectively, at a curing period of 3 days and by 33 and 35%, respectively, at a curing period of 28 days. The SMK had a significant impact on the internal pore structure of the hardened samples, and the number of pores with a diameter of larger than 3000 nm significantly decreased. Because the hydration products filled the pores, the microstructure of the HCS was further refined and densified with the addition of SMK. Submicron metakaolin has a simple process and high activity, which can significantly improve the performance of the cement slurry. Therefore, submicron metakaolin has the potential for practical engineering applications.

scholarly journals Characteristics of Ordinary Portland Cement Using the New Colloidal Nano-Silica Mixing Method

2019 ◽  
Vol 9 (20) ◽  
pp. 4358 ◽  
Author(s):  
Taewan Kim ◽  
Sungnam Hong ◽  
Ki-Young Seo ◽  
Choonghyun Kang
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Setting Time ◽  
Sem Analysis ◽  
New Method ◽  
Nano Silica ◽  
Substitution Method ◽  
Replacement Method ◽  
Mechanical And Microstructural Properties ◽  
Mixing Water

This study applies a new method of mixing colloidal nano-silica (CNS). Previous studies have used powdered nano-silica or colloidal nano-silica and applied a binder weight substitution method. In this study, we tried to use ordinary Portland cement (OPC) as a binder and replace CNS with weight of mixing water. CNS was replaced by 10%, 20%, 30%, 40%, and 50% of the mixing water weight. The flow value, setting time, compressive strength, hydration reactant (X-ray diffractometer; XRD), pore structure (mercury intrusion porosimetry; MIP), thermal analysis, and scanning electron microscopy (SEM) analysis were performed. Experimental results show that the new substitution method improves the mechanical and microstructural properties through two effects. One is that the weight substitution of the mixing water shows a homogeneous dispersion effect of the nano-silica particles. The other is the effect of decreasing the w/b ratio when the CNS is substituted because the CNS is more dense than the mixing water. Therefore, we confirmed the applicability of mixing water weight replacement method as a new method of mixing CNS.

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