scholarly journals Evaluation of Carbon Nanotube Incorporation in Cementitious Composite Materials

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1504 ◽  
Author(s):  
Ana Catarina Jorge Evangelista ◽  
Jorge Fernandes de Morais ◽  
Vivian Tam ◽  
Mahfooz Soomro ◽  
Leandro Torres Di Gregorio ◽  
...  

Over the last decades, new materials with outstanding performance have been introduced in the construction industry. Considering these new technologies, it is worth mentioning that nanotechnology has revolutionized various areas of engineering. In the area of civil engineering and construction, cement is used for various purposes and the search to improve its performance has been receiving growing interest within the scientific community. The objective of this research was to evaluate the behavior of cement mortar produced by the addition of multi-walled carbon nanotubes (MWCNTs) in different concentrations by comparing their physical and mechanical properties with the properties of the nanotube-free composite. Motivated by the lack of consensus in the literature concerning to the optimal dosage of CNTs in cementitious matrices, three different carbon nanotube ratios, 0.20, 0.40 and 0.60 wt % Portland cement, were investigated with the aim of evaluating the mechanical properties. Destructive tests were carried out to determine the compressive strength, flexural strength and split tensile strength. Additionally, a non-destructive test was performed to determine the dynamic elastic modulus and density. Scanning electron microscopy (SEM) images showed the interaction between the MWCNTs and the hydration products of Portland cement mortar. The results indicated the potential contribution of 0.40 wt % cement CNTs to the enhancement of the mechanical properties of the cement composite as a promising construction material.

2020 ◽  
Vol 15 (4) ◽  
pp. 185-197
Author(s):  
Daniel Hatungimana ◽  
Şemsi Yazici ◽  
Şevket Orhan ◽  
Ali Mardani-Aghabaglou

ABSTRACT Portland cement is extensively used as a binder in concrete production. However, with Portland cement production, 5% of the natural resources used in this production are consumed, constituting 5–7% of the total CO2 emission. In order to mitigate the environmental problems associated with cement production, styrene-butadiene rubber latex was used as cement replacement up to 20%. In this study, compressive strength, flexural strength, unit weight, water absorption, open porosity, water sorptivity and the chloride ion permeability of Portland cement mortar mixtures modified by styrene-butadiene rubber (SBR) polymeric latex were investigated. For this purpose, the sand/cement ratio and the water/cement ratio were kept constant as 3/1 and 0.5, respectively. In addition to the control mixture containing no polymer, 1, 2, 3, 5, 10 and 20 wt.% of cement was replaced with SBR. In this way, seven mortar mixtures were prepared. Mixed curing (wet cure and dry cure) method was applied to the mortar specimens. Results showed that up to a 5% replacement level, it is possible to improve the mechanical properties of cement mortars with SBR latex addition. However, at a 10% and 20% replacement level, SBR had a significant detrimental effect on the mechanical properties of polymer modified mortars. However, the transport properties decreased with the incorporation rate of SBR latex and the detrimental effect of SBR replacement was more pronounced in 20% SBR mortar mixtures.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 792 ◽  
Author(s):  
Yaogang Tian ◽  
Dong Lu ◽  
Jianwei Zhou ◽  
Yuxuan Yang ◽  
Zhenjun Wang

This study proposes a new cement mortar incorporating damping aggregate (DA) and investigates the mechanical properties and damping property of the cement mortar. Four types of DA were prepared, lightweight aggregate presaturated water and three types of polymer emulsion. Further, the effects of polypropylene fiber and rubber powder on the performance of the cement mortar were studied. The experimental results showed that the damping ratio of specimens containing 70% DA was approximately three times higher than that of the reference mortar, with a slight decrease in the mechanical properties. Adding fiber was more effective than rubber powder in improving the damping ratio of the cement mortar, and the optimal dosage of fiber was 0.5%.


2015 ◽  
Vol 815 ◽  
pp. 164-169
Author(s):  
Ng Hooi Jun ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Husin ◽  
Soo Jin Tan ◽  
Mohd Firdaus Omar

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.


2021 ◽  
Vol 7 (2) ◽  
pp. 226-235
Author(s):  
Faisal K. Abdulhussein ◽  
Zahraa F. Jawad ◽  
Qais J. Frayah ◽  
ِAwham J. Salman

This paper investigates the effect of nano-papyrus cane ash as an additive on concretes’ mechanical and physical properties. Three types of concrete mixtures, 1:2:4, 1:1.5:3, and 1:1:2 were prepared for each mixture, nano-papyrus ash was added in five different dosages of 0.75, 1.5, 3, 4.5, and 6% by weight of cement; therefore, eighteen mixes would be studied in this work. Physical properties represented by dry density and slump were also measured for each mix. Moreover, to evaluate the mechanical properties development split tensile strength and compressive strength were obtained at age (7 and 28). Results manifested that the adding of nano ash developed the compressive strength and split tensile strength of concrete and the maximum enhancement recognized in the mixes with a content of 4.5% nano-papyrus in each studied mixture in this work. The slump test results indicated that the workability of concrete increased with adding nano-papyrus ash gradually with increasing nanoparticles' content. As well as, dry density was significant increased with nano-papyrus ratio; greater values were recorded in mixtures with 1.5-4.5% content of nano-papyrus. When comparing the concrete mixes used, it was found that the best results were obtained with 1:1:2 mixtures. This remarkable improvement in concrete properties considers the nano-papyrus is considered a cement economical and useful replacement for traditional construction material. Doi: 10.28991/cej-2021-03091649 Full Text: PDF


2015 ◽  
Vol 65 ◽  
pp. 1222-1228 ◽  
Author(s):  
Xiang Shu ◽  
Ryan K. Graham ◽  
Baoshan Huang ◽  
Edwin G. Burdette

2017 ◽  
Vol 21 ◽  
pp. 213-218 ◽  
Author(s):  
Marinela Barbuta ◽  
Adrian Alexandru Şerbănoiu ◽  
Costel Cadere ◽  
Catalina Mihaela Helepciuc

The quantities of wastes, generated in industry are increasing every year. Their utilization became a priority for solving pollution problem and save energy and resources. The wastes are investigated as materials for obtaining new concretes with different applications. Polymer concrete is a composite material, in which the aggregates of different sorts are bound together by a resin. As in the case of cement concrete, different types of wastes (slag, glass, marble, etc.) can replace the aggregates or they can be added in the concrete composition as filler (silica powder, fly ash, calcareous powder, etc). The use of wastes presents some advantages such as: obtaining of new products at lower prices, in some cases with improved properties; consuming of wastes helps to clean the environment; preservation of natural resources which are replaced by wastes; etc.In the experimental study, marble waste is used for obtaining epoxy polymer concrete. The effects of this type of waste on the mechanical properties of polymer concrete were investigated. Two types of concrete were prepared: one with powder of marble as addition and the other type with aggregates of marble waste. The mechanical properties (compressive strength, flexural strength, split tensile strength) were experimentally determined and compared with the characteristics of epoxy polymer concrete (considered as reference mix). The microstructure of polymer concrete with marble waste was analyzed by SEM images. The marble waste influenced the mechanical properties of epoxy polymer concrete. Higher values of mechanical properties were obtained when the marble was used as aggregates. As addition in epoxy polymer concrete, the dosage and finesse of marble had influenced the values of mechanical properties.


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