Modified Nano Silica by Acrylate for High Performance Hard Coating

This research work presents the role of nano silica (NS) on properties of high performance concrete. This study evaluates the influence of nano silica in three percentages (1%, 2%, 3 %,) by weight of cement. Several tests including mechanical properties and flexural test were performed to understand the influence of nano silica on behavior of concrete. It was determined that Portland cement replaced with 3% by weight with nano silica could accelerate C-S-H gel structure at early stage of hydration. In return this increases water permeability resistance of concrete specimens and acts as filler material that enhances micro structure as well as activator to promote pozzolanic activity and this will pave the way for producing good quality concrete

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Matrix Optimization of Ultra High Performance Concrete for Improving Strength and Durability

Materials ◽

10.3390/ma14226944 ◽

2021 ◽

Vol 14 (22) ◽

pp. 6944

Author(s):

Julio A. Paredes ◽

Jaime C. Gálvez ◽

Alejandro Enfedaque ◽

Marcos G. Alberti

Keyword(s):

Silica Fume ◽

High Performance ◽

Mercury Intrusion Porosimetry ◽

High Performance Concrete ◽

Silica Sand ◽

Nano Silica ◽

Ultra High Performance Concrete ◽

Matrix Optimization ◽

Binder Ratio ◽

Strength And Durability

This paper seeks to optimize the mechanical and durability properties of ultra-high performance concrete (UHPC). To meet this objective, concrete specimens were manufactured by using 1100 kg/m3 of binder, water/binder ratio 0.20, silica sand and last generation of superplasticizer. Silica fume, metakaolin and two types of nano silica were used for improving the performances of the concrete. Additional mixtures included 13 mm long OL steel fibers. Compressive strength, electrical resistivity, mercury intrusion porosimetry tests, and differential and thermogravimetric thermal analysis were carried out. The binary combination of nano silica and metakaolin, and the ternary combination of nano silica with metakaolin and silica fume, led to the best performances of the UHPC, both mechanical and durable performances.

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The effect of Vietnam’s nano-silica on mechanical properties of high-performance concrete

Transport and Communication Science Journal ◽

10.47869/tcsj.72.1.9 ◽

2021 ◽

Vol 72 (1) ◽

pp. 76-83

Author(s):

Lam Le Hong ◽

Lam Dao Duy ◽

Huu Pham Duy

Keyword(s):

Compressive Strength ◽

Silica Fume ◽

High Performance ◽

High Performance Concrete ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Nano Silica ◽

Nano Sio2 ◽

Curing Period ◽

Compressive Strength Test

The demand for High Performance Concrete (HPC) is steadily increasing with massive developments. Conventionally, it is possible to use industrial products such as silica fume (SF), fly ash, as supplementary cementitious materials (SCM), to enhance the attributes of HPC. In recent years, nano-silica (NS) is used as an additive in added mainly to fill up the deviation arises with the addition of SF for HPC. This study aims to optimize the proportion of NS (produced in Vietnam) in the mixture used for fabricating 70 MPa high-performance concrete. SiO2 powder with particle size from 10 to 15 nm were used for mixing. A series of compressive strength test of HPC with nano-SiO2 varied from 0 to 2.8 percent of total of all binders (0%, 1.2%, 2%, 2.8%), and the fixed percentage of silica fume at 8% were proposed. Results show compressive strength increases with the increase of nano-SiO2, but this increase stops after reaching 2%. And at day 28 of the curing period, only concrete mixture containing of 8% silica fume and 2% nano-SiO2, had the highest compressive strength.

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