Effects of Modified Metakaolin Using Nano-Silica on the Mechanical Properties and Durability of Concrete

Shafiq, Nasir; Kumar, Rabinder; Zahid, Muhammad; Tufail, Rana Faisal

doi:10.3390/ma12142291

Cited by 53 publications

(18 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Textile reinforced concrete (TRC) has the superior characteristics of crack resistance, impact resistance, and durability properties, which has been widely applied in lightweight thin-walled structures, such as large span arches, shells, and domes [1][2][3]. TRC matrix has a better flowability because of the coarse aggregates completely replaced by the fine aggregates with different gradations, but the strength, stiffness, and elastic modulus of TRC matrix are adversely affected [4,5]. Therefore, developing a fine-grained matrix concrete with good strength and flowability is the first step is to achieve the excellent performance of TRC.…”

Section: Introductionmentioning

confidence: 99%

Flow Mechanism and Strength Characteristics of Textile Reinforced Concrete Mixed with Colloidal Nano-SiO2

Shi

Wang

et al. 2021

Geofluids

View full text Add to dashboard Cite

In order to develop textile reinforced concrete (TRC) with good flowability and strength, colloidal nano-SiO2 (CNS) is adopted to improve the performance of TRC. The flowability, compressive strength, flexural strength, and four-point bending tests of TRC matrix with CNS are carried out, and the changes of internal micromorphological characteristics of TRC matrix are analyzed by combining with scanning electron microscopy. The results show that the CNS has an inhibitory effect on the flowability of TRC matrix, and the greater the amount of admixture is, the smaller the slump expansion of TRC matrix is. The compressive strength and flexural strength of TRC matrix show a trend of increasing and then decreasing as the amount of CNS increases, and the compressive strength reaches the maximum at each age (7 d, 14 d, 28 d) when CNS and silica fume replace 5% cement by 1 : 4 equal mass. The flexural strength reaches the maximum at each age (7 d, 14 d, 28 d) when 5% cement is replaced by CNS and silica fume with 3 : 7 equal mass. The flexural strength increases with the increase of CNS admixture. It is found by electron microscope scanning that the incorporation of CNS consumes more Ca(OH)2, refines the Ca(OH)2 crystal size, and generates more C-S-H gels. These C-S-H gels are distributed in a net-like pattern inside the concrete, filling the internal pores, effectively densifying the interfacial transition zone between the cementitious material and the aggregates, and optimizing the internal structure.

show abstract

Section: Introductionmentioning

confidence: 99%

Flow Mechanism and Strength Characteristics of Textile Reinforced Concrete Mixed with Colloidal Nano-SiO2

Shi

Wang

et al. 2021

Geofluids

View full text Add to dashboard Cite

show abstract

“…Silica fume has a high cost and is mainly used for concrete with high or ultra-high performances, with replacement dosages up to 10% in mass of binder. Metakaolin addition, despite having significant energy footprint and cost associated to its production, is eco-friendlier than Portland cement and it can also improve fresh and hardened properties when used in binary or ternary binder combination [26,27]. Nevertheless, fly ash addition is well known by its fineness and the spherical shape of its particles, which allows high water reductions and the increase of concrete packing density, resulting in significant performance improvements.…”

Section: Introductionmentioning

confidence: 99%

Durability and Time-Dependent Properties of Low-Cement Concrete

et al. 2020

View full text Add to dashboard Cite

The sustainability concerns of concrete construction are focused both on the materials’ eco-efficiency and on the structures’ durability. The present work focuses on the characterization of low cement concrete (LCC), regarding time-dependent and durability properties. LCC studies which explore the influence of the formulation parameters, such as the W/C (water/cement ratio), W/Ceq, (which represents the mass ratio between water and equivalent cement), W/B (water/binder) ratio, and the reference curves, on the aforementioned properties are limited. Thus, several LCC mixtures were formulated considering two dosages of binder powder, 350 and 250 kg/m3, the former with very plastic consistency and the latter with dry consistency, which were combined with a large spectrum of cement replacement rates (up to 70%), through adding fly ash and limestone filler, and with different compactness levels. The main objectives were to study the influence of the formulation parameters on the properties: shrinkage and creep, accelerated carbonation and water absorption, by capillarity, and by immersion. The lifetime of structures produced with the studied LCC was estimated, considering the durability performance, regarding the carbonation effect on the possible corrosion of the steel reinforcement. LCC mixtures with reduced cement dosage and high compactness, despite the high W/C ratios, have low shrinkage and those with higher strength have reduced creep, however depending on W/Ceq ratio. Those mixtures can be formulated and produced presenting good performance regarding carbonation resistance and, consequently, a long lifetime, which is mandatory for a sustainable construction. LCC with 175 kg/m3 of cement dosage is an example with higher lifetime than current concrete with 250 kg/m3 of cement; depending on the XC exposure classes (corrosion induced by carbonation), the amount of cement can be reduced between 37.5% and 42%, since the LCC with 175 kg/m3 of cement allows reducing the concrete cover below the minimum recommended, ensuring simultaneously the required lifetime for current and special structures.

show abstract

“…Recently, significant achievements had been made in the research on nanoparticle-modified cement, concrete, and other traditional building materials [16][17][18][19][20][21], and positive exploration had also been achieved in the modification of soil stabilizers. Shafiq [22] and Murthy et al [23] discussed the influence of nano-SiO 2 on the mechanical properties and durability of concrete. Kong et al [24] found that nano-SiO 2 could effectively improve the unconfined compressive strength of loess and improve pore structure.…”

Section: Introductionmentioning

confidence: 99%

Study on the Mechanism of Nano-SiO2 for Improving the Properties of Cement-Based Soil Stabilizer

et al. 2020

View full text Add to dashboard Cite

A new nano-soil stabilizer (N-MBER, Nanometer Material Becoming Earth into Rock) material was developed in this research by using the high activity and ultrafine properties of nano-SiO2 (NS), which were able to improve the properties of cement-based soil stabilizer and had broad application prospects. The results showed that (1) the strength of N-MBER obeyed a compound function relation with curing period and additive amount of NS. The relationship between strength and curing period obeyed an exponential function when the additive amount was constant. The strength and additive amount were a power function when the curing period was fixed. The compressive strength of N-MBER increased by more than 15% compared with MBER at day 28 of the curing period, and 50% compared with grade 32.5 cement. (2) The pozzolanic catalytic activity of NS significantly increased the amount of calcium silicate hydrate gel (C–S–H) in the N-MBER colloid. NS was also able to make the distribution of the network structure of colloidal space more uniform and improved the fractal dimension of particles by 0.05. The above results provide theoretical data for exploring the mechanism of soil stabilizer strength growth and for promoting the application of solid waste utilization.

show abstract

Effects of Modified Metakaolin Using Nano-Silica on the Mechanical Properties and Durability of Concrete

Cited by 53 publications

References 46 publications

Flow Mechanism and Strength Characteristics of Textile Reinforced Concrete Mixed with Colloidal Nano-SiO2

Flow Mechanism and Strength Characteristics of Textile Reinforced Concrete Mixed with Colloidal Nano-SiO2

Durability and Time-Dependent Properties of Low-Cement Concrete

Study on the Mechanism of Nano-SiO2 for Improving the Properties of Cement-Based Soil Stabilizer

Contact Info

Product

Resources

About