Effect of dispersibility of carbon nanotubes by silica fume on material properties of cement mortars: Hydration, pore structure, mechanical properties, self-desiccation, and autogenous shrinkage

2020 ◽  
Vol 265 ◽  
pp. 120318 ◽  
Author(s):  
Chiwon Song ◽  
Geuntae Hong ◽  
Seongcheol Choi
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Pore Structure ◽  
Silica Fume ◽  
Material Properties ◽  
Autogenous Shrinkage ◽  
Cement Mortars

Physical and mechanical characteristics of cement mortars and concretes with addition of clinoptilolite from Beli Plast deposit (Bulgaria), silica fume and fly ash

Clay Minerals ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 213-223 ◽  
Author(s):  
V. Lilkov ◽  
I. Rostovsky ◽  
O. Petrov
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Specific Pore Volume ◽  
Cement Mortars ◽  
Physical And Mechanical Characteristics

AbstractCement mortars and concretes incorporating clinoptilolite, silica fume and fly ash were investigated for changes in their physical and mechanical properties. It was found that additions of 10% clinoptilolite and 10% Pozzolite (1:1 mixture of silica fume and fly ash) were optimal for improvement of the quality of the hardened products, giving 8% and 13% increases in flexural and compressive strength respectively. The specific pore volume of the mortars incorporating zeolite decreased between the 28th and 180th day to levels below the values for the control composition due to the fact that clinoptilolite exhibits its pozzolanic activity later in the hydration. In these later stages, pores with radii below 500 nm increased at the expense of larger pores. The change in the pore-size distribution between the first and sixth months of hydration occurs mostly in the mortars with added zeolite.

Multiscale-Based Simulations of Longitudinal Mechanical Behaviors of Single-Walled Carbon Nanotubes Reinforced Polymer Nanocomposites

2013 ◽  
Author(s):  
James Han ◽  
Yu-Fu Ko ◽  
Hsien-Yang Yeh
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Mechanical Behavior ◽  
Polymer Nanocomposites ◽  
Polymer Matrix ◽  
Material Properties ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon ◽  
Reinforced Polymer ◽  
Walled Carbon Nanotubes

Longitudinal elastic mechanical behavior of the armchair and zigzag single-walled carbon nanotubes (SWCNTs) and the SWCNTs reinforced polymer nanocomposites are investigated. Finite element analysis (FEA) models of the SWCNTs and the SWCNTs reinforced polymer nanocomposites are developed utilizing multiscale modeling technique along with molecular structural mechanics (MSM), which provides material properties at molecular scale and establishes relations between the steric potential energy and the classic structural mechanics. Material properties of C-C bond were obtained using multiscale-based modeling method with the consideration of shear deformation. In addition, for the interphase layer interaction between the carbon molecules of SWCNTs and the molecules of polymer matrix, multiscale-based modeling method was utilized to obtain the stiffness of nonlinear spring elements representing the van der Waals interaction. It is observed that the mechanical behavior of the SWCNTs reinforced polymer nanocomposites is dictated by the mechanical behavior of the SWCNTs embedded in the polymer matrix. Furthermore, varying radius and length of the SWCNTs would affect the longitudinal elastic mechanical properties of the SWCNTs reinforced polymer nanocomposites. Specifically, the simulation results had demonstrated that longitudinal elastic mechanical properties of the SWCNTs reinforced polymer nanocomposites would vary due to different loading conditions applied, i.e., discrete and continuous loading conditions.

scholarly journals Estimating the Effect of Chirality and Size on the Mechanical Properties of Carbon Nanotubes Through Finite Element Modelling

2014 ◽  
Author(s):  
Muhammad Jibran Shahzad Zuberi ◽  
Volkan Esat
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Finite Element ◽  
Carbon Nanotube ◽  
Material Properties ◽  
Computational Models ◽  
Computational Modelling ◽  
Thermal And Electrical Properties ◽  
New Generation ◽  
Walled Carbon Nanotubes

Carbon nanotubes (CNTs) are considered to be one of the contemporary materials exhibiting superior mechanical, thermal and electrical properties. A new generation state-of-the-art composite material, carbon nanotube reinforced polymer (CNTRP), utilizes carbon nanotubes as the reinforcing fibre element. CNTRPs are highly promising composite materials possessing the potential to be used in various areas such as automotive, aerospace, defence, and energy sectors. The CNTRP composite owes its frontline mechanical material properties mainly to the improvement provided by the CNT filler. There are challenging issues regarding CNTRPs such as determination of material properties, and effect of chirality and size on the mechanical material properties of carbon nanotube fibres, which warrant development of computational models. Along with the difficulties associated with experimentation on CNTs, there is paucity in the literature on the effects of chirality and size on the mechanical properties of CNTs. Insight into the aforementioned issues may be brought through computational modelling time- and cost-effectively when compared to experimentation. This study aims to investigate the effect of chirality and size of single-walled carbon nanotubes (SWNTs) on its mechanical material properties so that their contribution to the mechanical properties of CNTRP composite may be understood more clearly. Nonlinear finite element models based on molecular mechanics using various element types substituting C-C bond are generated to develop zigzag, armchair and chiral SWNTs over a range of diameters. The predictions collected from simulations are compared to the experimental and computational studies available in the literature.

Piezoresistive Properties of Cement Mortar with Carbon Nanotube

2011 ◽  
Vol 284-286 ◽  
pp. 310-313
Author(s):  
Zhi Gang Liu ◽  
Li Rong Yang ◽  
Jun Cong Wei ◽  
Bao Hui Zhao ◽  
Xiao Xin Feng
Keyword(s):  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Silica Fume ◽  
Electrical Resistance ◽  
Cement Mortar ◽  
Strength Development ◽  
Cement Mortars ◽  
Multi Walled Carbon Nanotubes ◽  
Compressive Strength Development ◽  
Walled Carbon Nanotubes

The compressive strength and piezoresistive property of cement mortar with low adding level of multi-walled carbon nanotubes (MWCNTs) were investigated. Experimental results showed that the compressive strength of the MWCNTs/cement mortars increased with the adding amount of MWCNTs content for all the curing ages. Silica fume promoted the compressive strength development by well bonding with MWCNTs and filling effect. The electrical resistance changed synchronously with the compressive strength and the amount of the changes varied with the stress and MWCNTs addition levels. Higher MWCNTs doping level improved the piezoresistive sensitivity of the mortar. The mortar with silica fume (5-10% by weight of cement) exhibited better piezoresistive response than that without silica fume at the same MWCNTs doping levels.

The Effect of Pozzolanics on the Recycled Aggregates by Surface Treatment

2005 ◽  
Vol 486-487 ◽  
pp. 305-308 ◽  
Author(s):  
Jae Jun Kim ◽  
Sang Heum Youn ◽  
M.J. Cho ◽  
H.T. Shin ◽  
Jeong Bae Yoon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Surface Treatment ◽  
Water Absorption ◽  
Silica Fume ◽  
Recycled Aggregates ◽  
Cement Mortars ◽  
Pozzolanic Materials ◽  
Adsorption Treatment

To improve the mechanical properties of concretes containing recycled aggregates, pozzolanic materials such as Silica Fume and Meta Kaolin were used to decrease the porosity of the recycled aggregates. These pozzolanic aterials were adhered on the surface of recycled aggregates and closed the open pores so that the water absorption was decreased 1~2% as the amount of adsorption was increased. Compressive strength of cement mortars and concretes using surface treated recycled aggregates reached above 95% of the strength of its natural counterparts. Investigation of the microstructures using the scanning lectron micrographs showed the formation of dense interface after the adsorption treatment of pozzolanics to recycled aggregates.

Nanotechnology: The Emerging Field of Civil Engineering Particularly in Developing Countries

2014 ◽  
Vol 974 ◽  
pp. 329-334
Author(s):  
Tanvir Manzur ◽  
Ma Bashar Emon ◽  
Kabirul Islam
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Developing Countries ◽  
Construction Industry ◽  
Silica Fume ◽  
Cement Hydration ◽  
Civil Engineering ◽  
Alkali Silicate ◽  
The World ◽  
Research On Application

Nanotechnology has taken the world of science by a storm and construction industry is no exception. The most important aspect of construction industry that can be influenced by nanotechnology is cement and concrete. Recent research on application of carbon nanotubes (CNT), both single-walled and multi-walled, shows significant increase in mechanical properties of concrete. Other properties of concrete e.g. durability, permeability, cement hydration etc. can be conveniently influenced with the help of Alkali-Silicate Reaction (ASR) studies, nanoScale Silica Fume, integration of nanoParticles in cement-synthesis and a lot other methods. And as a matter of fact, the future of cement based construction industry seems to be shaped by nanotechnology as even developing countries like Bangladesh are coming forward now-a-days to harness the potential of this rapid growing field.

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