scholarly journals IMPACT OF MULTI-WALLED CARBON NANOTUBES ON WOOD SAWDUST EXTRACT CEMENT MORTAR

2019 ◽  
Vol 11 (4) ◽  
pp. 119-124
Author(s):  
Ekaterina Karpova ◽  
Gintautas Skripkiūnas ◽  
Grigory Yakovlev ◽  
Asta Kičaitė
Keyword(s):  
Carbon Nanotubes ◽  
Cement Paste ◽  
Cement Mortar ◽  
Setting Time ◽  
Final Setting Time ◽  
Wood Sawdust ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Mineral Additives ◽  
Time Density

It is well known that organic waste materials deteriorate the performance of concrete. The impregnation of organic aggregates and their application in combination with other chemical admixtures and mineral additives are used in order to improve the concrete properties in case of their modification by organic components. The current research is focused on the evaluation of impact of multi-walled carbon nanotubes (MWCNT) on the properties of cement systems prepared based on wood sawdust extract (WSE). The setting time, density, consistency, flexural and compressive strength, water absorption tests were undertaken. The retardation effect of (WSE) on the initial and final setting time of cement paste was observed. The additional modification of cement paste with WSE by MWCNT in the dosage of 0.005% by weight of cement (bwoc) did not show the significant changes in initial and final setting time. The application of MWCNT in the dosage of 0.005% bwoc contributed to the increase of early strength of cement mortar prepared with WSE.

scholarly journals Effect of Multi-Walled Carbon Nanotubes on Strength and Electrical Properties of Cement Mortar

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 79
Author(s):  
Elena Cerro-Prada ◽  
Rosalía Pacheco-Torres ◽  
Fernando Varela
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Properties ◽  
Flexural Strength ◽  
Mechanical Performance ◽  
Cement Mortar ◽  
Setting Time ◽  
Curing Time ◽  
Conductivity Enhancement ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

This work aims to investigate the effects of multi-walled carbon nanotubes (MWCNTs) on the strength and electrical properties of cement mortar. MWCNTs were added to cement mortar in four different concentrations: 0.00 wt.%, 0.01 wt.%, 0.015 wt.%, and 0.02 wt.% by the mass of cement. The consistency, density, setting time and compressive and flexural strength of mixes were tested and analyzed at 28 and 90 days curing time. Mechanical performance tests confirm an increase of 25% and 20% in the ultimate compressive and flexural strength respectively, which results from MWCNT 0.02 wt.% loading at 90 days curing time. The resistivity measurements in mortars with 0.01 and 0.015 wt.% MWCNT loading result up to 10% decrement at both 28 and 90 days curing. Activation energy calculations show fully accordance with these statements, resuming that 0.01 wt.% MWCNT appears to be the most effective loading scheme to produce certain conductivity enhancement in cement mortar.

scholarly journals Metakaolin Based Geopolymer Mortar Reinforced with Multi-Walled Carbon Nanotubes - A Case Study

2020 ◽  
pp. 47-58
Author(s):  
Pawandeep Kaur ◽  
Jaspal Singh ◽  
Manpreet Kaur ◽  
Ritesh Jain
Keyword(s):  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Sodium Hydroxide ◽  
Cement Mortar ◽  
Sodium Hydroxide Solution ◽  
Absolute Error ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Metakaolin based geopolymer mortars are presently considered as a feasible substitute to Ordinary Portland Cement mortar due to its various benefits. The present experimental investigation is planned by varying the concentrations of sodium hydroxide as 8M, 10M and 12M along with the variation of multi-walled carbon nanotubes (0, 0.25%, 0.50%, 0.75% and 1% by weight of the binder). For each specimen, the compressive strength was determined at the curing ages of 3, 7 and 28 days. The results clearly indicate that the incorporation of multi walled carbon nanotubes (MWCNTs) in the geopolymer matrixes enhances the compressive strength. Transmission electron microscope (TEM) was used to depict the microstructure and morphology of MWCNTs. The ultimate compressive strength was obtained by employing 12M concentrated sodium hydroxide solution along with 0.5% of MWCNTs in geopolymer mortar. The values of integral absolute error were computed for all the curing ages. All the values lie within the acceptable range (0 to 10%).

An Investigation on Behavior of Multi-Wall Carbon Nanotubes as an Additive to Cement

2018 ◽  
Vol 24 (8) ◽  
pp. 5832-5835
Author(s):  
A VijayaBhaskar ◽  
M Shanmugasundaram
Keyword(s):  
Carbon Nanotubes ◽  
Setting Time ◽  
Sem Analysis ◽  
Structural Behavior ◽  
Multi Wall Carbon Nanotubes ◽  
Initial Setting Time ◽  
Initial Setting ◽  
Cement Binder ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

In the present study an attempt was made to study the effect of multi wall carbon nanotubes (MWCNTs) on cement as an additive. The multi-wall carbon nanotubes used in this study has a diameter of 30 nm. This multi walled carbon nanotubes added as additives to cement were in percentage of 0.2, 0.4, 0.6, 0.8, 1.0 and 1.2 to weight of cement. Using this modified cement; Binder pastes and mortars were prepared and tested for its various behaviors. The tests were carried for normal consistency, initial setting time, final setting time and strength developments in MWCNTs modified cements. The mortars specimens were further studied for its micro structural behavior through scanning electron microscopy (SEM) analysis. The results show that multi-wall carbon nanotubes increases the strength parameters and micro structural behavior. There were no considerable changes in terms of to the high cost of multi-wall carbon nanotubes, 0.8 percentage can be the optimal percentage of additive in terms of performance and strength.

Dispersion of Carbon Nanotubes in Cement-Based Composites and Its Influence on the Piezoresistivities of Composites

2009 ◽  
Author(s):  
Baoguo Han ◽  
Xun Yu ◽  
Jinping Ou
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Cement Mortar ◽  
Sodium Dodecyl ◽  
Impulsive Loading ◽  
Repeated Loading ◽  
Sodium Dodecylbenzene Sulfonate ◽  
Dodecylbenzene Sulfonate ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (NaDDBS) are used as surfactants to improve the dispersion of multi-walled carbon nanotubes (MWNTs) in cement mortar and fabricate piezoresistive carbon-nanotube/cement mortar composite. The piezoresistivity of carbon-nanotube/cement mortar composite with different content levels of MWNTs and different surfactants were explored under repeated loading and impulsive loading. Experimental results indicate that NaDDBS has higher efficiency than SDS for the dispersion of MWNTs in cement mortar. The response of the electrical resistance of carbon-nanotube/cement mortar composite with NaDDBS to external force is more stable and sensitive than that of carbon-nanotube/cement mortar composite with SDS. These findings indicate that the use of NaDDBS is an effective way for improving the dispersion of MWNTs in cement-based composite and fabricating MWNTs filled cement-based composite with stable and strong piezoresistive response.

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.

scholarly journals Rheological Properties and Flow Behaviour of Cement-Based Materials Modified by Carbon Nanotubes and Plasticising Admixtures

Fluids ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 169
Author(s):  
Gintautas Skripkiunas ◽  
Ekaterina Karpova ◽  
Joana Bendoraitiene ◽  
Irmantas Barauskas
Keyword(s):  
Carbon Nanotubes ◽  
Rheological Properties ◽  
Yield Stress ◽  
Cement Paste ◽  
Shear Thickening ◽  
Plastic Viscosity ◽  
Flow Behaviour ◽  
Volume Coefficient ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

In this study, the rheological properties of cement paste modified by a suspension containing both multi-walled carbon nanotubes (MWCNT) and carboxymethyl cellulose (CMC) (MWCNT/CMC suspension) with different types of plasticising admixtures (Pl), such as lignosulphonate (LS), sulfonated naphthalene formaldehyde condensate (NF), and polycarboxylate ether (PCE) were evaluated. The increase in yield stress and plastic viscosity up to 20% was established in the case of the modification of cement-based mixtures by MWCNT in the dosage up to 0.24% by weight of cement (bwoc) without Pl and with LS and NF. The complex modification of cement paste by MWCNT and PCE increases the yield stress and plastic viscosity from the MWCNT dosage of 0.06% and 0.015% bwoc, respectively. The yield stress and plastic viscosity of cement paste with PCE enhanced by 265% and 107%, respectively, in a MWCNT dosage of 0.12% bwoc. MWCNT do not have a significant influence on the flow behaviour index of cement paste; however, in the case of usage of PCE, the shear thickening effect decreased from a MWCNT dosage of 0.03% bwoc. The significant reduction in the volume coefficient of water bleeding by 99, 100, and 83% was obtained with LS, NF, and PCE, respectively, with an increase in MWCNT dosage up to 0.24% bwoc.

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