scholarly journals Study on the Effect of Graphene Oxide with Low Oxygen Content on Portland Cement Based Composites

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 802 ◽  
Author(s):  
Andrius Kudžma ◽  
Jelena Škamat ◽  
Rimvydas Stonys ◽  
Andrejs Krasnikovs ◽  
Denis Kuznetsov ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Flexural Strength ◽  
Portland Cement ◽  
Reference Sample ◽  
Strengthening Mechanisms ◽  
Low Oxygen ◽  
Cement Pastes ◽  
Mechanical And Physical Properties ◽  
Oxygen Ratio ◽  
Equal Density

The current study presents research into the effect of graphene oxide (GO) with a carbon to oxygen ratio of 4:1 on the fluidity, hydration, microstructure, mechanical and physical properties of Portland cement pastes and mortars. The amounts of GO investigated were 0.02%, 0.04%, and 0.06% by weight of cement, while for mortars, an extra composition with 0.1% was also prepared. According to the results, the fluidity of cement paste and mortar increased and the hydration process was slightly retarded with the addition of GO. Despite this, improvements in compressive and flexural strength were established in the mortars containing GO. The maximum effects (~22% and ~6%, respectively) were obtained with the addition of 0.06% GO. The calculation of estimated strength proportional to samples of equal density showed that for mortars cured for 7 days the gain in strength was directly related to the gain in density. For mortar samples cured for 28 days, the estimated strength was found to be significantly higher than that of the reference sample, indicating that besides density there are other factors determining the improvement in strength of mortars modified with GO. The possible structure strengthening mechanisms are discussed.

scholarly journals Physical Properties of Concrete Containing Graphene Oxide Nanosheets

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1707 ◽  
Author(s):  
Yu-You Wu ◽  
Longxin Que ◽  
Zhaoyang Cui ◽  
Paul Lambert
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Graphene Oxide ◽  
Flexural Strength ◽  
Portland Cement ◽  
Physical Properties ◽  
Ordinary Portland Cement ◽  
Construction Materials ◽  
Split Tensile Strength ◽  
Cement Pastes

Concrete made from ordinary Portland cement is one of the most widely used construction materials due to its excellent compressive strength. However, concrete lacks ductility resulting in low tensile strength and flexural strength, and poor resistance to crack formation. Studies have demonstrated that the addition of graphene oxide (GO) nanosheet can effectively enhance the compressive and flexural properties of ordinary Portland cement paste, confirming GO nanosheet as an excellent candidate for using as nano-reinforcement in cement-based composites. To date, the majority of studies have focused on cement pastes and mortars. Only limited investigations into concretes incorporating GO nanosheets have been reported. This paper presents an experimental investigation on the slump and physical properties of concrete reinforced with GO nanosheets at additions from 0.00% to 0.08% by weight of cement and a water–cement ratio of 0.5. The study demonstrates that the addition of GO nanosheets improves the compressive strength, flexural strength, and split tensile strength of concrete, whereas the slump of concrete decreases with increasing GO nanosheet content. The results also demonstrate that 0.03% by weight of cement is the optimum value of GO nanosheet dosage for improving the split tensile strength of concrete.

The Flexural Strength and Fracture Toughness of a Normal and a High Strength Polymer Modified Portland Cement

1984 ◽  
Vol 42 ◽  
Author(s):  
N. B. Eden ◽  
J. E. Bailey
Keyword(s):  
Flexural Strength ◽  
Portland Cement ◽  
Interfacial Shear Strength ◽  
Fracture Behaviour ◽  
High Strength ◽  
Interfacial Shear ◽  
Water Soluble ◽  
Water Soluble Polymer ◽  
Cement Pastes ◽  
Cement Ratio

AbstractA model has been developed for the flexural strength of Portland cement pastes, based upon observed fracture behaviour of both normal and high strength pastes. Fibrillar or foil-like elements pull apart at a yield stress which is characteristic of the number of elements and interfacial shear strength. The former can be maximised by using a low water/cement ratio and the latter by inclusion of water-soluble polymer, followed by suitable drying. It is proposed that this is the mechanism by which high strength may be attained in Portland cement.

Controlling Physical Properties of Cementitious Matrixes by Nanomaterials

2010 ◽  
Vol 123-125 ◽  
pp. 639-642 ◽  
Author(s):  
Andrzej Cwirzen
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Flexural Strength ◽  
Portland Cement ◽  
Physical Properties ◽  
Frost Resistance ◽  
Autogenous Shrinkage ◽  
Carbon Nanofibres ◽  
Mechanical And Physical Properties ◽  
New Generation

The majority of concrete used nowadays is based on matrixes formed by hydrating Portland cement. Latest developments in nanosciences introduced a new generation of nano-sized materials possessing often remarkable mechanical and physical properties. These materials can be also used to improve or alter the characteristics of the binder matrixes based on Portland cement. The results showed that mechanical properties such as compressive and flexural strength can be increased by up to 50% by addition of for example 0.23wt% of carbon nanotubes. Carbon nanotubes and carbon nanofibres and/or nanosilica appeared to improve also the frost resistance. Other properties, such as autogenous shrinkage decreased significantly after addition of carbon nanofibres. Nanosilica enabled an immense densification of the hydrated binder matrix, which in turn improved for instance the durability and mechanical properties.

scholarly journals The effect of adding natural wastes on some properties of gypsum: تأثير إضافة المخلفات الطبيعية على بعض خواص الجبس

2021 ◽  
Vol 5 (5) ◽  
pp. 77-65
Author(s):  
Alaa Ahmad Zohir Kattan, Nada Altonji, Fatima Alsaleh Alaa Ahmad Zohir Kattan, Nada Altonji, Fatima Alsaleh
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Physical Properties ◽  
Thermal Insulation ◽  
Building Materials ◽  
Reference Sample ◽  
Basic Material ◽  
Mechanical And Physical Properties ◽  
Peanut Shells

In this research, the effect of adding some natural wastes to gypsum was studied in order to use them as thermal insulation materials in buildings and to recycle these wastes. Thermal insulation panels were installed from gypsum (as a basic material) and natural wastes (sawdust, peanut shells, wheat straw, cottonwood) at percentages (10, 15, 20) %, and some of their mechanical and physical properties, and their thermal conductivity were studied. The results indicated an improvement in some properties of gypsum after adding wastes, and obtaining thermal building materials that have better properties than the reference sample (gypsum) in some cases. Rough sawdust samples (SdR15, SdR20) achieved the highest compressive strength exceeding (4MPa). The flexural strength was for peanut shells samples (P10:1.76 MPa, P15:1.8 MPa), while the most efficient samples as thermal insulation were ground straw and smooth sawdust samples (SdS15, SdS20, GSt15, GSt20) where their thermal conductivity was (0.194-0.141W/m.K), which makes it acceptable according to the Syrian thermal insulation code.

Mechanical and Physical Properties of Early Carbonated High Initial Strength Portland Cement Pastes

2014 ◽  
Vol 634 ◽  
pp. 467-472
Author(s):  
Alex Neves Junior ◽  
Romildo Dias Toledo Filho ◽  
Jo Dweck ◽  
Eduardo de Moraes Rego Fairbairn
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Physical Properties ◽  
Early Age ◽  
Specific Mass ◽  
Silicate Phase ◽  
Cement Pastes ◽  
Initial Strength ◽  
Mechanical And Physical Properties ◽  
Carbonation Curing

After submitted to early age carbonation curing, mechanical and physical properties of high initial strength sulfate resistant Portland cement (HS SR PC) pastes were investigated, which were compared to those of non-carbonated reference pastes. Carbonation was performed for 1 and 24 hours, at the best conditions of CO2capturing, previously determined by the authors. Despite the compressive strength and elastic modulus of the 1h carbonated pastes were slightly higher than those of the reference pastes, their absorbed water content and porosity was slightly higher than that of the reference. In the case of 24h carbonation, its compressive strength decreases significantly because of its much higher porosity, although the new solid carbonated calcium silicate phase presents a much higher specific mass than those of the solid phases of the 1 hour and non-carbonated pastes.

scholarly journals The Influence of Cellulose Nanocrystals on the Hydration and Flexural Strength of Portland Cement Pastes

Polymers ◽  
2017 ◽  
Vol 9 (12) ◽  
pp. 424 ◽  
Author(s):  
Tengfei Fu ◽  
Francisco Montes ◽  
Prannoy Suraneni ◽  
Jeffrey Youngblood ◽  
Jason Weiss
Keyword(s):  
Flexural Strength ◽  
Portland Cement ◽  
Cellulose Nanocrystals ◽  
Cement Pastes

scholarly journals Enhanced flexural properties of aramid fiber/epoxy composites by graphene oxide

2019 ◽  
Vol 8 (1) ◽  
pp. 484-492 ◽  
Author(s):  
Yinqiu Wu ◽  
Bolin Tang ◽  
Kun Liu ◽  
Xiaoling Zeng ◽  
Jingjing Lu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Flexural Strength ◽  
Interfacial Shear Strength ◽  
Flexural Modulus ◽  
Weight Fraction ◽  
Interfacial Shear ◽  
Aramid Fiber ◽  
Epoxy Composites ◽  
Flexural Properties ◽  
Pure Epoxy

Abstract The reinforcing effect of graphene oxide (GO) in enhancing the flexural strength and flexural modulus of aramid fiber (AF)/epoxy composites were investigated with GO-AFs at a weight fraction of 0.1-0.7%. The flexural strength and flexural modulus of the composite reached 87.16 MPa and 1054.7 MPa, respectively, which were about 21.19% and 40.86% higher than those of the pure epoxy resin, respectively. In addition, the flexural properties and interfacial shear strength (IFSS) of composite reinforced by GO-AFs were much higher than the composites reinforced by AFs due to GO improved the interfacial bonding between the reinforcement material and matrix.

Hardened portland cement pastes of low porosity

1973 ◽  
Vol 3 (3) ◽  
pp. 279-293 ◽  
Author(s):  
Stephen Brunauer ◽  
Jan Skalny ◽  
Ivan Odler ◽  
Marvin Yudenfreund
Keyword(s):  
Portland Cement ◽  
Cement Pastes ◽  
Low Porosity

Effect of microcrystalline cellulose on geopolymer and Portland cement pastes mechanical performance

2021 ◽  
Vol 288 ◽  
pp. 123053
Author(s):  
Saulo Rocha Ferreira ◽  
Neven Ukrainczyk ◽  
Keoma Defáveri do Carmo e Silva ◽  
Luiz Eduardo Silva ◽  
Eduardo Koenders
Keyword(s):  
Portland Cement ◽  
Microcrystalline Cellulose ◽  
Mechanical Performance ◽  
Cement Pastes

Study on Waterproof and Water-Resistant Properties of Gypsum

2012 ◽  
Vol 476-478 ◽  
pp. 1585-1588
Author(s):  
Hong Pan ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Ordinary Portland Cement ◽  
Experimental Results ◽  
Softening Coefficient

The comprehensively modified effect of cement, VAE emulsion and self-made acrylic varnish on mechanical and water-resistant properties of gypsum sample was investigated and microstructure of gypsum sample was analyzed. Experimental results exhibit that absolutely dry flexural strength, absolutely dry compressive strength, water absorption and softening coefficient of gypsum specimen with admixture of 10% ordinary Portland cement and 6% VAE emulsion and acrylic varnish coated on its surface can respectively reach to 5.11MPa , 10.49 MPa, 8.32% and 0.63, respectively.

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