Mechanical properties and durability of concrete specimens containing nano silica in sulfuric acid rain condition

Mahdikhani, Mahdi; Bamshad, Omid; Shirvani, Mohammad Fallah

doi:10.1016/j.conbuildmat.2018.01.137

Cited by 109 publications

(40 citation statements)

References 23 publications

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“…The largest variation occurred for the ethyl silicate mortar with an increase of 30.5 percentage points (pp) (increased from 8.6% at 28 days to 39.2% at 90 days), and the zinc stearate mortar was the least affected with an increase in mass loss of 16.8 points. These results are consistent with those obtained in other studies, where cementitious materials were seen to decrease mass with increase in exposure time [3,10,28].…”

Section: Mass Loss Caused By Sulphuric Acid Exposuresupporting

confidence: 93%

“…However, Qing et al [9] indicate that on using nanosilica as admixture instead of silica fume, a higher compressive strength is obtained, especially in the early stages. Nanosilica is currently being used in cementitious materials to increase: (i) resistance, due to its pozzolanic effect [10,11]; and (ii) durability, due to the reduction of porosity and improvement of the microstructure of cement-basedmaterials [12]. A recent study analysed the effect of nanosilica on concretes exposed to sulphuric acid; the results indicated a better performance of nanosilica concretes, since their compressive strength was greater and mass loss was lower [10].…”

Section: Introductionmentioning

confidence: 99%

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Pore Structure Degradation of Different Cement Mortars Exposed to Sulphuric Acid

et al. 2019

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Acid attack causes the deterioration of construction material surfaces. The objective of this study was to investigate the degradation of different types of cement mortar in terms of variations in pore size distribution obtained by mercury intrusion porosimetry (MIP), mass loss, and compressive strength. The mortars were manufactured with nanosilica, zinc stearate, and an ethyl silicate coating. After curing (28 days), the samples were subjected to acid exposure for 90 days, immersed ina solution (3% w/w) of sulphuric acid (H2SO4). The results indicate that the mortars showed a more refined microstructure, with a higher proportion of smaller pores (<100 nm) compared to the control mortar. The 28-day and 90-day compressive strength variations of mortars were also determined by observing pronounced reduction due to the appearance of expansive compounds responsible for microcracking.

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Section: Mass Loss Caused By Sulphuric Acid Exposuresupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Pore Structure Degradation of Different Cement Mortars Exposed to Sulphuric Acid

et al. 2019

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“…Its good corrosion resistance is due to the Cr2O3-based passive film, the passivity of which is improved by the presence of nickel [1,2]. Reinforced concrete is the most widely used construction material due to its cost effectiveness, versatility and environmental compatibility, as well as its exceptional mechanical characteristics, longevity and corrosion resistance [3,4]. The great resistance to corrosion is owing to the chemical stability of the hydrated Portland cement and the passivity of steel in the highly alkaline pore solution of the concrete, its pH ranging from ~12.5 to ~13.5 [5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Effect of fly ash on the corrosion performance and structural integrity of stainless steel concrete rebars in acid rain and saline environments

Lekatou

Tsouli

Nikolaidis

et al. 2019

Frattura Ed Integrità Strutturale

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The corrosion behavior of 304L stainless steel rebars in an alkaline solution simulating new concrete subjected to acid rain attack and a mildly to slightly acidic solution simulating corroded cover concrete that exposed the reinforcement to direct acid rain attack, was investigated by reverse polarization. Both solutions contained Ca(OH)2 and fly ash (0-25 wt.% of the dry mixture). Concrete cubes containing 0-25 wt.% fly ash and reinforced with 304L rebars were subjected to salt spraying for 4 m. Although the polarization behaviors in the two electrolytes were different, the relative trends with respect to the fly ash contents were similar. The beneficial effect of fly ash (up to 20 wt.%) on the corrosion resistance of 304L rebars was demonstrated. However, a deteriorating effect was realized at 25 wt.% addition. Partial replacement of cement by fly ash did not significantly affect the tensile properties of the 304L rebar before or after 4 m of salt spraying. The elastic modulus and percent elongation presented a slight decrease after 4 m of salt spraying, irrespectively of FA content. Corrosion-wise, 304L can replace 316L stainless steel provided that FA has been added to the concrete mixture, even at low contents (10 or 15 wt.%).

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“…As one of the most used building material, concrete is inevitably exposed to different acidic substances and from this point of view the durability of concrete structures in aggressive environments has become a major concern over the past several decades [1][2][3]. Suitable compressive strength, large resources of concrete components and cost effectiveness are concrete characteristics that are desirable for various applications [4,5]. When concrete is exposed to acidic environments, deterioration of material occurs, because acidic molecules penetrating the concrete reacts with compounds in concrete matrix [4,6].…”

Section: Introductionmentioning

confidence: 99%

“…Suitable compressive strength, large resources of concrete components and cost effectiveness are concrete characteristics that are desirable for various applications [4,5]. When concrete is exposed to acidic environments, deterioration of material occurs, because acidic molecules penetrating the concrete reacts with compounds in concrete matrix [4,6]. British chemist R.A. Smith first observed the pollution of acid rain in 1852, which attracted much attention from researchers, environmentalists and experts from many different fields all over the world [7].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of concrete deterioration under simulated acid rain environment

Smolakova

Estokova

2019

Selected Scientific Papers - Journal of Civil Engineering

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Acid rain is identified as one of the most serious environmental problems nowadays and it is mainly a mixture of sulfuric and nitric acids. Deterioration of concrete structures exposed to aggressive acid rain attack is a key durability issue that affects the performance and maintenance costs of vital civil infrastructures. The motivation for understanding the acid rain corrosion process is high because of the early age deterioration of many concrete structures exposed to acid rain. The main objective of this study was to investigate the durability of concrete specimens with different supplementary cementitious materials, such as fly ash, zeolite and blast furnace slag against acid rain attack. Experiments of acid rain simulation influence on the composites were carried out for 7 weeks and parameters like visual changes, absorbability and leachability of calcium and silicon ions were evaluated. The increase in absorbability was detected for all samples while the sample with blast furnace slag was identified to be the most durable in this point of view. The most durable sample considering leached-out calcium and silicon ions was found to be sample with fly ash.

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Mechanical properties and durability of concrete specimens containing nano silica in sulfuric acid rain condition

Cited by 109 publications

References 23 publications

Pore Structure Degradation of Different Cement Mortars Exposed to Sulphuric Acid

Pore Structure Degradation of Different Cement Mortars Exposed to Sulphuric Acid

Effect of fly ash on the corrosion performance and structural integrity of stainless steel concrete rebars in acid rain and saline environments

Evaluation of concrete deterioration under simulated acid rain environment

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