Effect of Nanosilica on Mechanical and Thermal Properties of Cement Composites for Thermal Energy Storage Materials

Jittabut, Pongsak

doi:10.1016/j.egypro.2015.11.454

Cited by 22 publications

(9 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, it was reported that after a cement paste was heated to 350ºC and 900ºC for six hours, the 28 day thermal conductivities of the cement paste mixed with 1-5% wt. nSiO 2 reduced by 38% (range: 0.42 -0.57 W/(m·K)) after heating to 900 °C compared to the paste at ambient temperature [Jittabut, 2015]. The results after heating to 350ºC were very close to those obtained at ambient temperature.…”

Section: Influence Of Nanomaterials On Thermal Conductivitysupporting

confidence: 64%

Influence of nanomaterials on properties of lime and hemp/lime composites for energy efficient wall design

O'Flaherty

Khalaf

Starinieri

2019

Advances in Building Energy Research

View full text Add to dashboard Cite

Section: Influence Of Nanomaterials On Thermal Conductivitysupporting

confidence: 64%

Influence of nanomaterials on properties of lime and hemp/lime composites for energy efficient wall design

O'Flaherty

Khalaf

Starinieri

2019

Advances in Building Energy Research

View full text Add to dashboard Cite

“…Furthermore, it was reported that the 28 day, the cement paste mixed with 1-5% wt. nSiO 2, thermal conductivity reduced by 38% (range: 0.42 -0.57 W/mK) after a cement paste was heated to 350ºC and 900ºC for six hours and then after heating to 900 °C compared to the paste at ambient temperature (Jittabut, 2015). The results after heating to 350ºC were very close to those obtained at ambient temperature.…”

Section: Influence Of Nanomaterials On Thermal Conductivity From Prevsupporting

confidence: 62%

“…The thermal conductivity was reduced 38 % compared with pure cement at 900ºC. The thermal conductivity was in the range 0.42-0.57 W/mK after the composite was heated to 900ºC (Jittabut, 2015). Thermal conductivity of cement decreased by mixing waste glass (replacing the river sand by waste milled glass) and nanosilica (1 and 3 wt.…”

Section: 422mentioning

confidence: 99%

High Performance Reinforced Hemp-Lime Nanocomposite Construction Materials

Khalaf¹

View full text Add to dashboard Cite

The aim of the project is to develop high performance, lightweight, durable, and environmentally friendly construction materials. Construction materials should have high compressive and flexural strength, low porosity, low thermal conductivity, low shrinkage and high water vapour permeability (breathability). The following materials were selected to achieve this aim; lime was selected as the base matrix material with hemp (fibres and shives) and wood glue (Poly vinyl acetate, PVAc). Specially selected nanomaterials were used as fillers. The properties of the developed material were used to design an eco-friendly wall consisting of a central 'Core' which will be the load bearing element, highly insulative layers with low thermal conductivity 'Insulators' and outer rendering materials for enhanced aesthetics purpose and breathability 'Renders'. The research conducted in this project enabled a number of different construction materials to be developed, each exhibiting their own characteristics to enable the aims and objectives of the project to be achieved. A summary of the findings is as follows: A load bearing wall requires relatively high compressive and flexural strengths of about 5 MPa and 4.0 MPa, respectively or higher. The 'Core' material designed consisted of 10 wt. % hemp fibres, 12 % PVAc/L, 4 wt. % nZnO (nanozinc oxide) and lime (NHL5, which its quantity was 1 kg for each batch of 4 samples for the whole project) and prepared using air curing method. The compressive strength was 17.7 MPa and the flexural strength was greater than 7.0 MPa, which were the highest results of strength throughout the project. The same mentioned mixture (10 wt. % hemp fibres, 12 % PVAc/L, 4 wt. % nanozinc oxide of lime) was cured using 'Ovendrying', the strengths in compression and flexure were still considerable, being 10 MPa and 4 MPa respectively which were more than the minimum limit of loadbearing material. This material, therefore, due to its high compressive strength, used as the 'Core' load bearing element of the proposed wall in the absence of a timber framework. The 'Insulator' was developed using a water removal 'Solvent exchange' technique and the mixture was 20 wt. % hemp shives, 12 % PVAc/L, 4 wt. % nanozinc oxide and lime. The thermal conductivity was 0.06 W/mK, much lower than that of pure lime which was 0.16 W/mK. The 'Insulator' will be applied in two layers, one on either side of the 'Core'. The 'Render' was developed using lime and 4 wt. % nanozinc oxide by wt. of lime and cured via air curing. It possessed a low porosity (18 %) in comparison to that of pure lime (36.4 %) and low thermal conductivity,  (0.13 W/mK) in comparison to pure lime 0.16 W/mK cured by solvent exchange. Shrinkage was lowest in a Render material containing 4 % wt. nZnO, averaging 750 microstrain (µs) compared to the control sample (lime only) of 2428 µs. Chopped fibres, PVAc and nanozinc oxide were used for the first time with lime and no other examples of this exist in the literature (in the best knowledge of the researcher). Water ...

show abstract

“…Nonstationary methods can obtain results in minutes, as compared to stationary methods, which can take several hours to do the same. Despite some objections, nonstationary methods are used for the thermal measurements of cement grouts [ 35 ], gypsum [ 5 , 18 , 36 , 37 , 38 ] and concrete modified with aggregates and waste materials [ 17 , 39 , 40 , 41 ]. The above-mentioned short summary of the frequent use of nonstationary measurements of thermal conductivity shows that these methods are growing in popularity, and that they are considered reliable.…”

Section: Resultsmentioning

confidence: 99%

Comparison of the Thermal Properties of Geopolymer and Modified Gypsum

et al. 2021

View full text Add to dashboard Cite

The paper presents the results of research concerning the influence of micromaterials on the heat conductivity coefficient λ, specifically heat Cp and thermal diffusivity a of modified gypsum and geopolymer. Microspheres, hydroxyethyl methylcellulose (HEMC) polymer, and aerogel were used as the gypsum’s modifying materials. The study also investigated an alkali potassium-activated methakaolin-based geopolymer with the addition of aluminium dust. During the measurements of thermal parameters, the nonstationary method was chosen, and an Isomet device—which recorded the required physical quantities—was used. When compared to the reference sample, a decrease in the thermal conductivity and diffusivity of the hardened gypsum— and a simultaneous increase in specific heat—was observed with the addition of micromaterials. The geopolymer sample was characterized by the lowest value of thermal conductivity, equal to 0.1141 W/(m·K). It was over 62% lower than the reference sample containing only gypsum. The experimental values of the thermal conductivity of the gypsum samples with the addition of HEMC, aerogel and microspheres were, respectively, over 23%, 6%, and 8% lower than those of the unmodified gypsum samples. The lowest values of thermal conductivity were observed in the case of the gypsum samples modified with polymer; this resulted from the fact that the polymer caused the greatest change in the structure of the gypsum’s composite, which were expressed by the lowest density and highest porosity.

show abstract

Effect of Nanosilica on Mechanical and Thermal Properties of Cement Composites for Thermal Energy Storage Materials

Cited by 22 publications

References 8 publications

Influence of nanomaterials on properties of lime and hemp/lime composites for energy efficient wall design

Influence of nanomaterials on properties of lime and hemp/lime composites for energy efficient wall design

High Performance Reinforced Hemp-Lime Nanocomposite Construction Materials

Comparison of the Thermal Properties of Geopolymer and Modified Gypsum

Contact Info

Product

Resources

About