Effects of carbon nanotubes on expanded glass and silica aerogel based lightweight concrete

Suman Kumar Adhikary,Simona Tučkutė,Žymantas Rudžionis,Deepankar Kumar Ashish

doi:10.1038/s41598-021-81665-y

Abstract

This study is aimed to investigate the effect of carbon nanotubes on the properties of lightweight aggregate concrete containing expanded glass and silica aerogel. Combinations of expanded glass (55%) and hydrophobic silica aerogel particles (45%) were used as lightweight aggregates. Carbon nanotubes were sonicated in the water with polycarboxylate superplasticizer by ultrasonication energy for 3 min. Study results show that incorporating multi-wall carbon nanotubes significantly influences the compressive strength and microstructural performance of aerogel based lightweight concrete. The addition of carbon nanotubes gained almost 41% improvement in compressive strength. SEM image of lightweight concrete shows a homogeneous dispersal of carbon nanotubes within the concrete structure. SEM image of the composite shows presence of C–S–H gel surrounding the carbon nanotubes, which confirms the cites of nanotubes for the higher growth of C–S–H gel. Besides, agglomeration of carbon nanotubes and the presence of ettringites was observed in the transition zone between the silica aerogel and cementitious materials. Additionally, flowability, water absorption, microscopy, X-ray powder diffraction, and semi-adiabatic calorimetry results were analyzed in this study.

Highlights

This study is aimed to investigate the effect of carbon nanotubes on the properties of lightweight aggregate concrete containing expanded glass and silica aerogel
The results of the present study revealed that the flowability of Carbon nanotubes (CNTs)-LWAC was influenced by the quantity of CNT
Study results analyses the viability of using multiwall carbon nanotube (MWCNT) to improve the compressive strength of lightweight aggregate concrete prepared by silica aerogel and expanded glass aggregates

Summary

Introduction

This study is aimed to investigate the effect of carbon nanotubes on the properties of lightweight aggregate concrete containing expanded glass and silica aerogel. Study results show that incorporating multi-wall carbon nanotubes significantly influences the compressive strength and microstructural performance of aerogel based lightweight concrete. Zou et al.[8] and Collins et al.[10] reported that ultrasonication energy and polycarboxylate-based superplasticizer could significantly influence the mechanical and microstructural properties of CNT incorporated cementitious composites by optimally dispersing the CNTs within a concrete s tructure[8,10]. The main aim was to improve the strength property of aerogel concrete by reducing the separation gaps between silica aerogel and cementitious materials This is the first study that presents the use of CNTs to enhance the compressive strength property of lightweight concrete prepared with expanded glass aggregates and hydrophobic silica aerogel. The study investigates fluidity, water absorption, and microstructural analysis

Objectives

Methods

Results

Conclusion