scholarly journals Peculiarities of hydration of Portland cement with synthetic nano-silica

2017 ◽  
Vol 12 (2) ◽  
pp. 101-106 ◽  
Author(s):  
Galyna Kotsay
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Cement Hydration ◽  
Physical And Mechanical Properties ◽  
The Other ◽  
Nano Materials ◽  
Nano Silica ◽  
Other Hand ◽  
Materials Used

Abstract Application of nano-materials in cement products significantly, improves their properties. Of course, the effectiveness of the materials depends on their quantity and the way they are introduced into the system. So far, amongst nano-materials used in construction, the most preferred was nano-silica. This research investigated the effect of synthetic precipitated nano-silica on the cement hydration as well as, on the physical and mechanical properties of pastes and mortars. Obtained results showed that admixture of nano-silica enhanced flexural and compressive strength of cement after 2 and 28 days, however, only when admixture made up 0.5% and 1.0%. On the other hand, the use of nano-silica in the amount 2% had some limitations, due to its ability to agglomerate, which resulted in deterioration of the rheological and mechanical properties.

Effects of 0-30% Wood Ashes as a Substitute of Cement on the Strength of Concretes

2022 ◽  
Author(s):  
Theodore Gautier Bikoko ◽  
Jean Claude Tchamba ◽  
Valentine Yato Katte ◽  
Divine Kum Deh
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Greenhouse Gases ◽  
Negative Influence ◽  
Wood Ash ◽  
The Other ◽  
Other Hand ◽  
Strength Tests ◽  
Compressive Strength Of Concrete ◽  
Curing Age

To fight against the high cost and the increasing scarcity of cement and at the same time to reduce the CO2 greenhouse gases emission associated with the production of Portland cement, two types of wood ashes as a substitute of cement in the production of concretes were investigated. In this paper, we substituted cement by two types of species of wood ashes namely, avocado and eucalyptus ashes following the proportions ranging from 0% to 30 % on one hand, and on the other hand, we added these two types of species of wood ashes namely, avocado and eucalyptus ashes following the proportions ranging from 0% to 10 % by weight of cement in the concrete samples. After 7, 14 and 28 days of curing, compressive strength tests were conducted on these concrete samples. The findings revealed that using wood ashes as additives/admixtures or as a substitute of cement in the production/manufacturing of concrete decreased the compressive strength of concrete. Hence, it can be said that wood ash has a negative influence on the strength of concrete. At three percent (3%) and ten percent (10%) of addition, the wood ash from eucalyptus specie offers better resistance compared to the wood ash from avocado specie, whereas at five percent (5%) of addition, the wood ash from avocado specie offers better resistance compared to the wood ash from eucalyptus specie. At thirty percent (30%) of substitution, the wood ash from eucalyptus specie offers better resistance compared to the wood ash from avocado specie. The compressive strengths increase with the increase of curing age.

Influence of Portland Cement Addition in the Physical and Mechanical Properties of Epoxy Resin

2015 ◽  
Vol 1088 ◽  
pp. 411-414 ◽  
Author(s):  
Francisco Augusto Zago Marques ◽  
Carlos Eduardo G. da Silva ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr ◽  
Túlio Hallak Panzera ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Composite Material ◽  
Portland Cement ◽  
Physical Properties ◽  
Epoxy Resin ◽  
Modulus Of Elasticity ◽  
Epoxy Matrix ◽  
Physical And Mechanical Properties ◽  
Response Variable

This research evaluated, with the of the analyses of variance (ANOVA), a composite material based on epoxy matrix phase reinforced with Portland cement (CP-II) particles (0%wt [100%wt of resin], 20%wt, 40%wt, 60%wt). The response-variable investigated were modulus of elasticity (E) and compressive strength (S), bulk density (ρB), apparent density (ρA) and porosity (P). The highest values of the modulus of elasticity were provided from the composites manufactured with 40wt% of cement addition. The inclusion of 60% of cement implies in a reduction in the mechanical properties when compared with the results of the composite manufactured with 40% of cement. For the physical properties, the gradually inclusion of cement provides increasing in the density of the composites, and reduce the porosity of the materials manufactured.

Review on the Effect of Bottom Ash in Performance of Portland Cement Mortar

2015 ◽  
Vol 815 ◽  
pp. 164-169
Author(s):  
Ng Hooi Jun ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Husin ◽  
Soo Jin Tan ◽  
Mohd Firdaus Omar
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Mechanical Performance ◽  
Cement Mortar ◽  
Bottom Ash ◽  
The Other ◽  
Other Hand

Utilization and suitability of bottom ash in Portland cement have been increasing significantly in recent year. Bottom ash has substantial effects on mechanical properties with different composition of replacement in mixture of bottom ash and Portland cement. Bottom ash was used to determine the feasibility of the substitution as recycling product from industry depending on the percentage of the bottom ash. On the other hand, bottom ash offers a better solution for maintaining materials characteristic of Portland cement mortar and also provide beneficial mechanical performance. The result of using bottom ash in Portland cement mortar showed that it could make better the mechanical properties and hence disposed bottom ash wastes safely in technical, economic and environmental methods.

scholarly journals Permeation Resistance of Sawdust Ash Blended Cement Laterized Concrete

2019 ◽  
Vol 21 (2) ◽  
pp. 76-83 ◽  
Author(s):  
Samuel Olufemi Folagbade ◽  
Aluko Olawale
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Blended Cement ◽  
The Other ◽  
Partial Replacement ◽  
Initial Surface ◽  
Surface Absorption ◽  
Conventional Concrete ◽  
Other Hand ◽  
Curing Age

This paper compared the initial surface absorption of conventional concrete and laterized concrete containing Portland cement (PC) and sawdust ash (SDA). Laterized concrete was produced at laterite contents of 15 and 30% as partial replacement for sand and SDA contents of 10 and 20% as partial replacement for PC. Compressive strengths at 28 days and initial surface absorption after 10 minutes (ISA-10) at 28, 60 and 90 days were determined at the water/cement ratios of 0.35, 0.50 and 0.65 and assessed at equal 28-day strengths of 25-35 N/mm2. At equal water/cement ratios, compressive strength reduced and ISA-10 increased with increasing content of laterite and SDA. On the other hand, compressive strength and resistance to surface absorption of the blended cement laterized concretes increased with increasing curing age. At equal strengths, all the blended cement laterized concretes have better resistance to surface absorption than the conventional PC concrete.

Effect of Nano-Silica Particles on the Fresh Properties of UHPC

2014 ◽  
Vol 629-630 ◽  
pp. 91-95
Author(s):  
Qian Qian Zhang ◽  
Jian Zhong Liu ◽  
Wei Lin
Keyword(s):  
Mechanical Properties ◽  
Cement Hydration ◽  
Physical And Mechanical Properties ◽  
Heat Evolution ◽  
Fresh Properties ◽  
Nano Silica ◽  
Cement Pastes ◽  
Binder Ratio ◽  
Nanosilica Particles ◽  
Water Binder Ratio

Nanotechnology is being used in UHPC for achieving more dense structural packing and better physical and mechanical properties. In this paper, nanosilica particles (0-1wt %) by cement were incorporated in cement pastes and mortars with water-binder ratio of 0.2, and their effect on fresh properties was addressed. The fresh properties of mixtures were investigated by spread, rheology and cohesiveness. In addition, effect of nanosilica on cement hydration was also investigated. The results show that significant increase of yield stress, viscosity and cohesiveness is observed with nanosilica above 0.005 wt% by cement, but nanosilica with content below 0.005% presents an improvement of workability especially with content of 0.002%. Moreover, the addition of nanosilica in cement pastes obviously accelerates the early cement hydration rate, but does not increase the cumulative heat evolution.

Influence of Nano-SiO2 and Nano-CaCO3 on the Mechanical Properties of Concrete with Different Strength Grades

2011 ◽  
Vol 250-253 ◽  
pp. 480-484 ◽  
Author(s):  
Miao Zhou Huang ◽  
Tao Meng ◽  
Xiao Qian Qian ◽  
Jin Jian Zhang
Keyword(s):  
Mechanical Properties ◽  
The Other ◽  
Early Age ◽  
Nano Materials ◽  
Strength Grade ◽  
Other Hand

The flow ability, mechanical properties and microstructure of concrete with different strength grades affected by nano-SiO2and nano-CaCO3was studied. The experiment results showed that the strength of concrete at early age was increased by adding the nano-materials if the strength grade of concrete was not high. But the strength at the age of 28 days was not affected a lot by adding these nano-materials. On the other hand, it was not useful to the strength if the strength grade of concrete was high.

scholarly journals Influence of Different Nano Materials on Mechanical Properties of Plain Concrete

2019 ◽  
Vol 4 (6) ◽  
pp. 129-134
Author(s):  
Mohamad Farouk Abd-elmagied
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Iron Oxide ◽  
Cement Content ◽  
Plain Concrete ◽  
Nano Materials ◽  
Nano Silica ◽  
Concrete Compressive Strength ◽  
Concrete Mix ◽  
Different Types

This research aims to study the influences of three types of Nano materials on concrete compressive strength, considered Nano types were Nano-Iron Oxide Fe2O3 (NF), Nano-Manganese Oxide Mn2O3 (NM), and Nano-Silica SiO2 (NS). A constant concrete mix and water content were considered. The used percentages of different types of (NF, NM, and NS) that replaced by the cement content were (0.5, 1.0, 2.0, and 5.0%) of mixture weight (wt). The results demonstrated that the (NS) Nano type has better effect than other types on the concrete compressive strength.

Effects of Alloying Elements on Physical and Mechanical Properties of Co-Al-W-Based L12/fcc Two-Phase Alloys

2014 ◽  
Vol 783-786 ◽  
pp. 1195-1200 ◽  
Author(s):  
Katsushi Tanaka ◽  
Haruyuki Inui
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Lattice Mismatch ◽  
Physical And Mechanical Properties ◽  
The Other ◽  
Alloying Elements ◽  
Alloying Element ◽  
Two Phase ◽  
Solvus Temperature ◽  
Other Hand

The changes in the γ’ solvus temperature and the volume fraction of Co-Al-W based alloys with fcc / L12 two-phase microstructures upon alloying with quaternary elements have been investigated. All investigated quaternary elements, except for Fe and Re, increase the γ’ solvus temperatures of Co-Al-W based alloys with varying efficiencies depending on quaternary element. On the other hand, the variation of the γ’ volume fraction with alloying depends on the alloying element. Of the investigated quaternary elements, Ta is found to be the most effective in increasing the γ’ solvus temperature of Co-Al-W based alloys. The lattice mismatch significantly increase upon alloying with Ta of 4at.%, which destroys the coherent cuboidal structure.

scholarly journals Glass Cullet as Additive to New Sustainable Composites Based on Alumina Binder

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3423
Author(s):  
Aleksandra Powęzka ◽  
Paweł Ogrodnik ◽  
Jacek Szulej ◽  
Mariusz Pecio
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physical And Mechanical Properties ◽  
Recycled Aggregate ◽  
Strength Testing ◽  
Glass Cullet ◽  
Construction Engineering ◽  
Hydraulic Binder ◽  
Materials Used ◽  
The Impact

The article investigated the possibility of reusing heat resistant glass cullet to improve the mechanical properties of high-temperature composites. This is an excellent recycled aggregate that may be used as a substitute for alumina cement, and for fine natural aggregate in the production of concrete based on hydraulic binder. The experimental programme comprised of strength testing conducted on 40 × 40 × 160 mm cuboidal samples. The model mixture was modified by filler that comprised glass recyclate, amounting to 5%, 10%, and 15% of the mass of gravel and cement. Given the degree of glass grounding, use was made of two fractions, 0/4 and 0/0.125 mm. Six modified mixtures were produced. Tests were then carried out on their selected physical and mechanical properties as well as the impact of temperature, topography, and chemical composition exerted on the composite. Next, the progress and development of compressive strength and flexural strength after 14 and 28 days of curing were studied. Results showed that concrete with a 5% content of glass dust had a maximum compressive strength at the level of 85.1 MPa. Results also showed that concrete (Zk.I.5) heated at a temperature of 500 °C had a 46% higher compressive strength when compared to basic concrete (Z.I.0). The results show that it is possible to use the described components to obtain a composite that meets requirements imposed on structural materials used in construction engineering.

scholarly journals Development and Evaluation of Nano-Silica Sustainable Concrete

2021 ◽  
Vol 11 (7) ◽  
pp. 3041
Author(s):  
Habib H. Alqamish ◽  
Adil K. Al-Tamimi
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
The Other ◽  
Construction Process ◽  
Nano Silica ◽  
Sem Images ◽  
Granulated Blast Furnace Slag ◽  
Concrete Mixtures ◽  
Other Hand ◽  
Furnace Slag

In the last decade, nanomaterials made a major breakthrough in the concrete industry by providing the concrete with unique properties. Earlier studies have shown improvement in the early strength of concrete that can accelerate the construction process. In this study, 1% and 2% of nano-silica were added to concrete mixtures that contain 30% and 70% ground granulated blast-furnace slag (GGBS). Adding 1% of nano-silica to the 30% GGBS mixture showed an increase in the compressive strength by 13.5%, 7.8%, 8.1%, and 2.2% at one day, three days, seven days, and twenty-eight days, respectively. The 2% of nano-silica increased the 30% GGBS mixture’s compressive strength less effectively by 4.3%, 7.6%, and 4.9% at three days, seven days, and 28 days, respectively, when compared to the 1%. On the other hand, adding 1% and 2% of nano-silica reduced the 70% GGBS mixtures’ compressive strength. Moreover, nano-silica reduced the deformability of the mixtures significantly, which caused the increase in the Young’s modulus. The flexural strength of the 30% GGBS mixtures had similar behavior as the 28-day compressive strength. On the other hand, the flexural strength of the 70% GGBS mixtures increased as the nano-silica increased. Nano-silica addition improved the microstructure and the interface structure of the mixtures due to its high pozzolanic activity and the nano-filler effect, which is confirmed by RCPT results and SEM images.

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