Experimental Investigation and Image Processing to Predict the Properties of Concrete with the Addition of Nano Silica and Rice Husk Ash

Siva Avudaiappan,Supriya Prakatanoju,Raj Das,Rishi Gupta,Radhamanohar Aepuru,Mugahed Amran,Erick I Saavedra Flores,Nikolai Vatin,Roman Fediuk

doi:10.3390/cryst11101230

Abstract

The use of the combination of ultrafine rice husk ash (RHA) and nano silica (NS) enhances the compactness of hardened concrete, but there is still a lack of studies that address the effects of NS and RHA on the workability, mechanical properties and pore microstructure of concrete. This study mainly aims to investigate the influence of the pore size distribution in multiphysics concrete model modified by NS and RHA and to determine the workability and mechanical properties of concrete with NS and RHA. In this work, NS and RHA were used as 0, 5, 10, 15 and 20% replacements of ordinary Portland cement (OPC) in concrete grade M20. Concrete mixed with NS and RHA showed improved performance for up to 10% addition of NS and RHA. Further addition of NS and RHA showed a decrease in performance at 7, 14 and 28 days. The decrease in concrete porosity was also found to be up to 10% when adding NS and RHA to cement. Image processing was performed on the cement-based materials to describe the microstructure of the targeted material without damage. The results from the experimental and tomography images were utilized to investigate the concrete microstructure and predict its inner properties.

Highlights

nano silica (NS) is manufactured using thermo-decomposition, sol-gel of silica fume and vaporphase reaction
The voids and porosity of concrete were minimized by incorporating the NS and rice husk ash (RHA). − When NS is added to the concrete mix, the amount of CSH gel formed in the matrix increases, which helps to fill the pores in concrete
NS modify concrete is extremely durable. − The mechanical qualities of concrete combined with RHA and NS have improved by up to 10% over the control mix

Summary

Introduction

NS is manufactured using thermo-decomposition, sol-gel of silica fume and vaporphase reaction. The use of admixtures, minerals, or artificial waste materials can provide sustainable concrete with moderate cost and several benefits in terms of avoiding environmental pollution by effectively disposing of waste or by-products, which could pollute lands, water, and air to a large extent [4]. In this investigation, RHA and NS are considered waste, which could potentially be used to partially replace fine aggregate to improve concrete strength. Crystals 2021, 11, 1230 to its porosity, pore size characteristics, cement concentration, aggregate type, exposure conditions, and other factors [17]

Materials

Mix Design and Mixing Procedure

Flexural Strength

Material Properties

Findings

Conclusions