scholarly journals Utilization of Thermally Treated SiC Nanowhiskers and Superplasticizer for Cementitious Composite Production

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4062
Author(s):  
Nagilla Azevedo ◽  
José Andrade Neto ◽  
Paulo de Matos ◽  
Andrea Betioli ◽  
Maciej Szeląg ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cement Hydration ◽  
Cement Matrix ◽  
Cementitious Composites ◽  
Cementitious Composite ◽  
Beneficial Effects ◽  
Marginal Effects ◽  
Composite Production ◽  
Hardened Properties ◽  
Thermally Treated

Nanomaterials are potential candidates to improve the mechanical properties and durability of cementitious composites. SiC nanowhiskers (NWs) present exceptional mechanical properties and have already been successfully incorporated into different matrices. In this study, cementitious composites were produced with a superplasticizer (SP) and 0–1.0 wt % SiC NWs. Two different NWs were used: untreated (NT-NW) and thermally treated at 500 °C (500-NW). The rheological properties, cement hydration, mechanical properties, and microstructure were evaluated. The results showed that NWs incorporation statistically increased the yield stress of cement paste (by up to 10%) while it led to marginal effects in viscosity. NWs enhanced the early cement hydration, increasing the main heat flow peak. NWs incorporation increased the compressive strength, tensile strength, and thermal conductivity of composites by up to 56%, 66%, and 80%, respectively, while it did not statistically affect the water absorption. Scanning electron microscopy showed a good bond between NWs and cement matrix in addition to the bridging of cracks. Overall, the thermal treatment increased the specific surface area of NWs enhancing their effects on cement properties, while SP improved the NWs dispersion, increasing their beneficial effects on the hardened properties.

scholarly journals Effect of Fibre Types on the Tensile Behaviour of Engineered Cementitious Composites

2021 ◽  
Vol 8 ◽  
Author(s):  
Mingzhang Lan ◽  
Jian Zhou ◽  
Mingfeng Xu
Keyword(s):  
Mechanical Properties ◽  
Experimental Result ◽  
Tensile Behaviour ◽  
Cementitious Composites ◽  
Matrix Interface ◽  
Cementitious Composite ◽  
Engineered Cementitious Composite ◽  
Fibre Bridging ◽  
The Difference ◽  
Fibre Matrix

Engineered cementitious composite (ECC) is a group of ultra-ductile fibre-reinforced cementitious composites, characterised by high ductility and moderate content of short discontinuous fibre. The unique tensile strain-hardening behaviour of ECC results from a deliberate design based on the understanding of micromechanics between fibre, matrix, and fibre–matrix interface. To investigate the effect of fibre properties on the tensile behaviour of ECCs is, therefore, the key to understanding the composite mechanical behaviour of ECCs. This paper presents a study on the fibre-bridging behaviour and composite mechanical properties of ECCs with three types of fibres, including oil-coated polyvinyl alcohol (PVA) fibre, untreated PVA fibre, and polypropylene (PP) fibre. The experimental result reveals that various fibres with different properties result in difference in the fibre-bridging behaviour and composite mechanical properties of ECCs. The difference in the composite mechanical properties of ECCs with different fibres was interpreted by analysing the fibre-bridging behaviour.

scholarly journals Effect of Carbon Nanotube Size on Compressive Strengths of Nanotube Reinforced Cementitious Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Tanvir Manzur ◽  
Nur Yazdani ◽  
Md. Abul Bashar Emon
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotube ◽  
High Performance ◽  
Construction Material ◽  
High Potential ◽  
Cement Matrix ◽  
Cementitious Composites ◽  
Cement Composites ◽  
Nanoscale Science ◽  
20 Nm

Application of nanoscale science to construction material has already begun. In recent times, various nanofibers have raised the interest of researchers due to their exceptional mechanical properties and high potential to be used as reinforcement within cement matrix. Carbon nanotube (CNT) is one of the most important areas of research in the field of nanotechnology. The size and exceptional mechanical properties of CNT show their high potential to be used to produce high performance next generation cementitious composites. In this study, an attempt has been made to investigate the effect of size of CNTs on compressive strengths of CNT reinforced cement composites. Seven different sizes of multiwalled nanotubes (MWNTs) were used to produce MWNT-cement composites. A trend was observed regarding the effect of nanotube size on compressive strength of composites in most cases. MWNT with outside diameter (OD) of 20 nm or less exhibited relatively better performance. Smaller MWNT can be distributed at much finer scale and consequently filling the nanopore space within the cement matrix more efficiently. This in turn resulted in stronger composites.

scholarly journals Effect of Delaminated MXene (Ti3C2) on the Performance of Cement Paste

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jianping Zhu ◽  
Genshen Li ◽  
Chunhua Feng ◽  
Libo Wang ◽  
Wenyan Zhang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Cement Paste ◽  
Cement Hydration ◽  
Hydration Heat ◽  
Hydration Process ◽  
Cement Matrix ◽  
Cement Composites ◽  
Hydrated Cement ◽  
Hydration Products

Delaminated MXene was incorporated into cement to improve the properties of cement composites, and its effects on the hydration process, microstructures, and mechanical properties were investigated, respectively. The investigation results showed that delaminated MXene was well-dispersed in the cement matrix and significantly reinforced the compressive strength of cement, especially when the addition is 0.01 wt%. Meanwhile, the total hydration heat of cement hydration and the quantity of hydration products were increased with the addition of delaminated MXene. In addition, the formation of HD C-S-H gel was promoted, and the microstructure of hydrated cement became more compact.

Mechanical Properties of Engineered Cementitious Composites Mixture

2014 ◽  
Vol 567 ◽  
pp. 428-433 ◽  
Author(s):  
Bashar S. Mohammed ◽  
Muhammad Hafiz Baharun ◽  
Muhd Fadhil Nuruddin ◽  
Odu Paul Duku Erikol ◽  
Nadhir Abdulwahab Murshed
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
The Self ◽  
Cementitious Composite ◽  
Fresh Properties ◽  
Self Compacting Concrete ◽  
Engineered Cementitious Composite ◽  
Hardened Properties ◽  
Pva Fiber

The aim of the research is to develop engineered cementitious composite mixtures satisfying the self-compacting concrete requirements and to evaluate the hardened properties of self-compacted ECC mixtures. To enhance the concrete performance, PVA is used. The PVA improved some characteristics and properties of the concrete. Ten mixes with different Polyvinyl Alcohol (PVA) fiber contents (0.0%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5% and 5.0%) have been prepared. Three cubes (100mm x 100mm x 100mm), three beams (100mm x 100mm x 500mm) and three cylinders (150mm diameter and 300mm height) have been cast for each mix and tested at the age of 7 and 28 days for compressive strength and at age of 28 days for splitting and flexural strength. The V-funnel, L-box and slump test also have been conducted to access the fresh properties like workability and flowability of the concrete. The results indicated the increase in the strength of the concrete and the formulas for predicting the compressive, splitting and flexural strength from PVA (%) has been developed.

scholarly journals Improvement of Flexural and Compressive Strength of Cement Mortar by Graphene Nanoplatelets

2021 ◽  
Vol 15 (1) ◽  
pp. 165-171
Author(s):  
Yu Chen ◽  
Xingchen Li ◽  
Chuangchuang Li ◽  
Nana Zhang ◽  
Ronggui Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Cement Hydration ◽  
Cement Mortar ◽  
Structural Strength ◽  
Graphene Nanoplatelets ◽  
Research Trend ◽  
Cement Matrix ◽  
Cement Composites ◽  
Engineering Structures

Background: In order to provide space for improving the durability of engineering structures by enhancing strength, the addition of nanomaterials has become a research trend in recent years. Graphene and its derivatives have unique properties and have been used in certain fields, which has also stimulated continuous and in-depth research on whether it can improve structural strength. Objective: This paper investigates the mechanical properties and mechanism of cement-based materials reinforced by Graphene Nanoplatelets (GNPs). Methods: Macroscopically, the flexural strength and compressive strengths of cement mortar were tested. Microscopically, the structure and composition were characterized and analyzed by SEM, EDS, and XRD. Results: The results show that the mechanical properties of modified cement mortar are directly related to the GNPs content. When the GNPs content is 0.04wt%, the flexural and compressive strength can still be increased by 12.8% and 33.9% after 28 d. Furthermore, the appropriate content of GNPs dispersed in the cement matrix played a role in promoting cement hydration. The interconnection with hydration products further reduces cracks and pores so that the cement composites form a denser microstructure. Conclusion: The results obtained above would provide references for understanding the reinforcement mechanism of GNPs.

Carbon nanotubes and superplasticizer reinforcing cementitious composite for aerostatic porous bearing

2017 ◽  
Vol 231 (11) ◽  
pp. 1397-1407 ◽  
Author(s):  
Leandro J da Silva ◽  
Tulio H Panzera ◽  
Luciano MG Vieira ◽  
Jaime G Duduch ◽  
Christopher R Bowen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Carbon Nanotube ◽  
Low Cost ◽  
Physical And Mechanical Properties ◽  
Cementitious Composites ◽  
Cementitious Composite ◽  
Thrust Bearings ◽  
Porous Bearing

Cementitious composites are low cost and readily manufactured materials which can be used for specialist applications such as the production of aerostatic porous bearings. A design of experiment was used to identify the effects of superplasticizer additions and carbon nanotube inclusions on the physical and mechanical properties of cementitious composites which can be applied as porous restrictor in aerostatic thrust bearings. The presence of carbon nanotubes was able to increase the bulk density, the compressive strength and the modulus of elasticity, and also decrease the apparent porosity of the composites. The composite made with 0.4 wt.% of superplasticizer and 0.05 wt.% of carbon nanotubes achieved acceptable properties for the use as double-layered porous restrictor in aerostatic thrust bearings.

scholarly journals Application of novel synthesized nanocomposites containing κ-carrageenan/PVA/eggshell in cement mortars

2020 ◽  
Vol 70 (340) ◽  
pp. 235
Author(s):  
I. Sanrı-Karapınar ◽  
A. O. Pehlivan ◽  
S. Karakuş ◽  
A. E. Özsoy-Özbay ◽  
A. U. Yazgan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cement Mortar ◽  
Cement Matrix ◽  
Cementitious Composites ◽  
Triple Combination ◽  
Strain Capacity ◽  
Preliminary Attempt ◽  
Cement Mortars ◽  
Compressive And Flexural Strengths ◽  
First Time

This study is a preliminary attempt to present the preparation and the first time a κ-carrageenan/PVA/eggshell nanostructure is used as a novel biodegradable and homogeneous nanostructure in cement composition. In order to clearly understand the effects these additives have on the mechanical properties of cementitious composites, they were synthesized in double and triple combinations and added into mortar mixtures. Three different cement mortar specimens were prepared by integrating the additives in ratios of 0, 0.1, 0.5 and 1% by cement weight and flexural and compressive strengths of the specimens were determined at the ages of 7 and 28 days. The flowability of the presented nanostructures was also discussed. The results revealed a 10–11% increase in both compressive and flexural strengths for the specimens prepared with the triple combination of the proposed additives. Moreover, strain capacity was enhanced as a result of the efficient dispersion of additives in the cement matrix.

scholarly journals Nanostructure, Self-Assembly, Mechanical Properties, and Antioxidant Activity of a Lupin-Derived Peptide Hydrogel

Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 294
Author(s):  
Raffaele Pugliese ◽  
Anna Arnoldi ◽  
Carmen Lammi
Keyword(s):  
Mechanical Properties ◽  
Antioxidant Activity ◽  
Self Assembly ◽  
Antioxidant Activities ◽  
Functional Materials ◽  
Cd Spectroscopy ◽  
Beneficial Effects ◽  
Naturally Occurring ◽  
New Research ◽  
Peptide Hydrogel

Naturally occurring food peptides are frequently used in the life sciences due to their beneficial effects through their impact on specific biochemical pathways. Furthermore, they are often leveraged for applications in areas as diverse as bioengineering, medicine, agriculture, and even fashion. However, progress toward understanding their self-assembling properties as functional materials are often hindered by their long aromatic and charged residue-enriched sequences encrypted in the parent protein sequence. In this study, we elucidate the nanostructure and the hierarchical self-assembly propensity of a lupin-derived peptide which belongs to the α-conglutin (11S globulin, legumin-like protein), with a straightforward N-terminal biotinylated oligoglycine tag-based methodology for controlling the nanostructures, biomechanics, and biological features. Extensive characterization was performed via Circular Dichroism (CD) spectroscopy, Fourier Transform Infrared spectroscopy (FT-IR), rheological measurements, and Atomic Force Microscopy (AFM) analyses. By using the biotin tag, we obtained a thixotropic lupin-derived peptide hydrogel (named BT13) with tunable mechanical properties (from 2 to 11 kPa), without impairing its spontaneous formation of β-sheet secondary structures. Lastly, we demonstrated that this hydrogel has antioxidant activity. Altogether, our findings address multiple challenges associated with the development of naturally occurring food peptide-based hydrogels, offering a new tool to both fine tune the mechanical properties and tailor the antioxidant activities, providing new research directions across food chemistry, biochemistry, and bioengineering.

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