Effect of micro silica on fiber-reinforced self-compacting composites containing ceramic waste

Abstract

This paper aims to evaluate the impact of ceramic waste powder (CWP), micro silica (MS) and steel fiber (SF) on self-compacting mortar. CWP at ratios of 10 and 20%, and MS at 1 and 5% by weight of cement were replaced the cement. Beside, SF was added at ratios of 0.5 and 1% of cement. Mini slump flow diameter and mini V-funnel flow time tests were carried out to determine the workability of fresh composites. Compressive strength, flexural strength, water absorption, electrical resistivity and drying shrinkage tests were performed on hardened mortars. Scanning electron microscope (SEM) technique was employed to assess the microstructure. The results indicated that CWP reduced the mechanical properties by about 20% and increased permeability by about 14%. However, inclusion of micro silica particles improved the properties outstandingly. Compressive strength increased about 30% by inclusion of MS. It was also observed that the addition of fibers from 0.5% to 1% increased the flexural strength. This improvement was more obvious in samples with higher contents of micro silica. It can be reported that by including the both micro silica and steel fibers, the bonding between the cement paste and fibers was developed. Replacement of micro silica led to increase of electrical resistivity by about 99% in samples containing 20% ceramic waste powder. The microstructure studies confirmed the significant increase of density and uniformity of the hydration products in the presence of micro silica particles.

A Critical Review Examining the Characteristics of Modified Concretes with Different Nanomaterials

“…The resulting mixture hardens with the help of a chemical process called hydration and, finally, concrete is produced [35]. During the hydration process, crystals play an important role as they bind together and thus bind the components together to obtain dense concrete [34,36]. Greenhouse gas (GHG) emissions related to construction in Europe [19].…”

Effect of Micro-Silica on Fresh and Hardened Properties of Self-Compacting Concrete Reinforced with Glass and Polyvinyl Alcohol Fibres

“…One of the reasons for the increase in strength of SCC is the result of increase of bonding strength between the cement paste and fibres due to the good pozzolanic activity of micro silica. Due to the lower size of micro silica, the surface is for bonding becomes higher which in turn increases the efficiency of the bond [21]. The inclusion of micro silica also decreases the capillarity and porosity of the concrete mix.…”

“…The bonding strength between cement paste and fibre is one of the elements influencing the amount of stress imparted by the fibres [20][21]. Maximum stress transmitted to the fibres increases with bond strength.…”

“…The efficacy of the fibres is restricted because a good bond cannot be established between synthetic fibres and cementitious matrix. The use of micro silica may be regarded as one of the helpful alternatives to boost the fibre's efficacy in the matrix due to its good pozzolanic activity [21]. Micro-silica, also known as silica fume, is produced in an electric arc furnace while manufacturing elemental silicons or alloys containing silicon.…”

Investigation of Impact Resistance of High-Strength Portland Cement Concrete Containing Steel Fibers

“…Concrete is the most used building material, with an annual consumption of well over 25 billion tons [ 1 , 2 , 3 , 4 , 5 ]. The availability of ingredients, ease of casting in any shape, economy, high compressive strength, as well as good durability in various environmental conditions are the factors that make concrete such a versatile construction material [ 6 , 7 , 8 , 9 ].…”