Optimizing Compressive Strength of Micro- and Nano-silica Concrete by Statistical Method

Mahsa Zarehparvar-Shoja,Hamid Eskandari-Naddaf

doi:10.28991/cej-030939

Abstract

In recent years, the use of nano-particles to improve the properties of concrete has created a new perspective on concrete technology. Studies in this field indicate improved concrete properties and higher strength by adding nano and micro silica particles to concrete mixes. In this regard, 12 mixing designs with different amounts of these admixtures with three types of cement strength classes (525,425,325) and 36 cubic samples (10 × 10 × 10) were designed and tested to measure compressive strength, of which we have only used 6 mixing plans in this research. The purpose of this research is to present a new method for concrete mix design by optimizing principles. Therefore, in this paper, the Taguchi statistical methods and the factorial design of the optimal mixing plan for this type of concrete are used to reduce the number of experiments to predict the optimal composition of the materials. The results obtained from the MINITAB software show that the effect of combined micro-silica and nano-silica on the compressive strength is in one direction and the effect of these two factors is more than cement strength grade of the cement and also the optimal value for micro-silica and nano-silica are estimated to have an optimum amount of micro-silica and nano-silica of 95 and 38 grams, respectively.

Highlights

In order to produce a concrete with a particular compressive strength, various factors such as the amount of combinatorial components and its related admixture, as well as the amount and time of rotation of the mixing machine in each step, should be carefully considered [1,2,3,4]
2c, it is concluded that the highest compressive strength is obtained with the amount of nano-silica (38 g) and the amount of micro-silica (95 g)
As we study the two-factor slopes, the changes in micro- and nano-silica on the compressive strength are the same, so their effect is the same

Summary

Introduction

In order to produce a concrete with a particular compressive strength, various factors such as the amount of combinatorial components and its related admixture , as well as the amount and time of rotation of the mixing machine in each step, should be carefully considered [1,2,3,4]. One of the important factors is the rate of admixture in concrete, which we are referring to as micro-silica and nanosilica [5]. Due to the effects of using Nano-silica in concrete, including improving microstructures, reducing permeability, reducing porosity and increasing compressive strength it can be concluded that the use of nano-silica is valuable that Collapardi et al confirm this [6]. Nano-particles have shown special properties in concrete mix design due to their very small particle size and their high surface area [8]. Jo et al (2007) have shown in their experiments that the increase in compressive strength for mortars containing nano-silica is 3 to 12 percent [13]. The use of nano-silica in high-strength concrete can increase short-term and long-term strength

Objectives

Methods

Results

Conclusion