Aggressive Environment Resistance of Concrete Products Modified With Nano Alumina and Nano Silica

The service life of concrete products with exposure to an aggressive environment has raised great concerns in the past decades. Nanomaterials have been used as a promising approach to improve the environmental resistance of concrete products when exposed to synergistic attacks. The impacts of CaCl2 on nano-modified concrete, especially along with freeze/thaw (F/T) and wet/dry (W/D) cycles, were barely discussed. In this study, the impacts of CaCl2 along with F/T and W/D cycles on the nano SiO2 and Al2O3 modified concrete were investigated. The mass loss, flexural strength, compressive strength, and relative dynamic modulus of elasticity were tested to evaluate the durability of concrete products. The testing results indicate that the addition of nanoparticles has a distinctive effect on the environment resistance enhancement of concrete samples. The microstructure analysis demonstrates that with the addition of nanoparticles, high-density hydration products were formed, which is beneficial to the properties enhancement of concrete products. This study not only provides an approach to realize the nano modification on the durability of concrete products but also helps to design and fabricate environmentally resistant concrete products when exposed to a synergistic aggressive environment.

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Enhancement of concrete performance via mixed limestone and granite powders

10.21203/rs.3.rs-900543/v1 ◽

2021 ◽

Author(s):

Hao Zeng ◽

Jin Zhang ◽

Kai Zhang

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Phase Composition ◽

Synergistic Effect ◽

Environmental Conditions ◽

Erosion Resistance ◽

Hydration Products ◽

Freeze Thaw ◽

Composite Mixture ◽

Durability Of Concrete

Abstract The granite and limestone powders are commonly exploited as a replacement for cement; however, the effects of different mixing dosages of them on the mechanical properties and durability of concrete have not been scrutinized carefully. Under different environmental conditions, the compressive strength of the specimens is measured using cube compressive, splitting tensile, freeze-thaw cycles, and sulfate immersion tests. The phase composition of hydration products and microstructure is evaluated by SEM scanning analysis. The results indicate that the composite mixture of granite and limestone powders shows a complementary synergistic effect and improves the mechanical properties, freeze-thaw resistance, and sulfate erosion resistance of the concrete. The best values for the mechanical properties and freeze-thaw resistance are obtained when the dosages of granite and limestone powders in order are 10% and 5%. For the case of granite and limestone powders equal to 10% and 15%, respectively, the best sulfate erosion resistance is reported.

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Performance Deterioration of High Strength Concrete under Mixed Erosion and Freeze-Thaw Cycling

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.163-167.1655 ◽

2010 ◽

Vol 163-167 ◽

pp. 1655-1660

Author(s):

Jian Zhang ◽

Bo Diao ◽

Xiao Ning Zheng ◽

Yan Dong Li

Keyword(s):

Compressive Strength ◽

Elastic Modulus ◽

Mass Loss ◽

Modulus Of Elasticity ◽

Dynamic Modulus ◽

High Strength Concrete ◽

High Strength ◽

Freeze Thaw ◽

Strength Concrete ◽

Dynamic Modulus Of Elasticity

The mechanical properties of high strength concrete(HSC) were experimentally investigated under mixed erosion and freeze-thaw cycling according to ASTM C666(Procedure B), the erosion solution was mixed by weight of 3% sodium chloride and 5% sodium sulfate. The mass loss, relative dynamic modulus of elasticity, compressive strength, elastic modulus and other relative data were measured. The results showed that with the increasing number of freeze-thaw cycles, the surface scaled more seriously; the mass loss, compressive strength and elastic modulus continued to decrease; the relative dynamic modulus of elasticity increased slightly in the first 225 freeze-thaw cycles, then decreased in the following 75 cycles; the corresponding strain to peak stress decreased with the increase of freeze-thaw cycles. After 200 cycles, the rate of deterioration of concrete accelerated obviously.

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

Materials ◽

10.3390/ma12142291 ◽

2019 ◽

Vol 12 (14) ◽

pp. 2291 ◽

Cited By ~ 12

Author(s):

Nasir Shafiq ◽

Rabinder Kumar ◽

Muhammad Zahid ◽

Rana Faisal Tufail

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Statistical Analysis ◽

Second Phase ◽

Nano Silica ◽

Chloride Permeability ◽

Maximum Compressive Strength ◽

Rapid Chloride Permeability ◽

Anova Technique ◽

Durability Of Concrete

This paper discussed the effects of modified metakaolin (MK) with nano-silica (NS) on the mechanical properties and durability of concrete. In the first phase, trial mixes of concrete were prepared for achieving the desired value of the 28 days compressive strength, and the charge passed in rapid chloride permeability test (RCPT). In the second phase, statistical analysis was performed on the experimental results using the response surface method (RSM). The RSM was applied for optimizing the mix proportions for the required performance by exploiting the relationship between the mix characteristics and the corresponding test results. A blend of 10% MK + 1% NS as part of cement replacement exhibited the highest mechanical properties and durability characteristics of concrete; concrete mix showed that the 28-days compressive strength (CS) was 103 MPa, which was 15% greater than the CS of the control mix without MK or NS. The same mix showed more than 40% higher flexural and split-tensile strength than the control mix; also it resulted in a reduction of 73% in the rapid chloride permeability value. ANOVA technique was used for optimizing the nano-silica and metakaolin content for achieving maximum compressive strength and minimum RCPT value. Statistical analysis using ANOVA technique showed that the maximum compressive strength and lowest RCPT value could be achieved with a blend of 10% MK and 1.55% NS.

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The Synergistic Effects of Freeze-Thaw, Salt Attack and Bending Stress on Behavior of Reinforced Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.633.313 ◽

2014 ◽

Vol 633 ◽

pp. 313-321

Author(s):

Peng Fei Huang ◽

Yi Wang Bao

Keyword(s):

Compressive Strength ◽

Reinforced Concrete ◽

Dynamic Modulus ◽

Synergistic Effects ◽

High Strength ◽

Bending Stress ◽

Freeze Thaw ◽

Strength Concrete ◽

Damage Rate ◽

Normal Strength

The damage experiments of reinforced concrete (RC) samples under synergistic effects of cyclic freeze-thaw, deicing-salt attack, rebar corrosion and bending stress were investigated using a comprehensive experimental method. Synergistic effects of these factors on the damage evolvement of RC were studied by measuring the change of dynamic modulus of concrete, rebar strain and concrete strain. Experimental results showed similar rule in damage evolvement but different damage rate between the normal-strength concrete (C45, the 28-day compressive strength of 52 MPa) and the high-strength concrete (C70, the 28-day compressive strength of 77 MPa). The dynamic modulus of the reinforced concrete degraded with increasing effecting factors.

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Experimental Study of Compression and Carbonation in Concrete Subjected to Freeze-Thaw Environment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.887-888.814 ◽

2014 ◽

Vol 887-888 ◽

pp. 814-818

Author(s):

Li Xue Wang ◽

Xiao Ting Shan ◽

Yu Qing Zhang ◽

Chun Sheng Li ◽

Zai Xing Wang ◽

...

Keyword(s):

Experimental Study ◽

Compressive Strength ◽

Modulus Of Elasticity ◽

Dynamic Modulus ◽

Test Method ◽

Carbonation Depth ◽

Cement Ratio ◽

Water Cement Ratio ◽

Freeze Thaw ◽

Concrete Properties

In order to research the changes of concrete properties in freeze-thaw environment, five concrete samples with water-cement ratio respectively equal to 0.60, 0.65, 0.70, 0.75 and 0.80 were tested in freeze-thaw environment according to GB/T50082-2009 concrete rapid freeze-thaw cycles test method. Five samples were carried out 0, 25, 50, 75, 100 times faster freeze-thaw cycles test. With the increasing number of freeze-thaw cycles, the concrete relative dynamic modulus of elasticity loss rises, the compressive strength drops, and the carbonation depth increases. The greater the water-cement ratio of concrete specimens with freeze-thaw cycles, the greater the degree of damage increases.

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An Experimental Study on the Frost Resistance of High Performance Concrete Using Fly-Ash and Agent

Materials Science Forum ◽

10.4028/www.scientific.net/msf.904.179 ◽

2017 ◽

Vol 904 ◽

pp. 179-184

Author(s):

Seung Jo Lee

Keyword(s):

Experimental Study ◽

Compressive Strength ◽

Fly Ash ◽

Modulus Of Elasticity ◽

Dynamic Modulus ◽

Frost Resistance ◽

High Performance ◽

High Performance Concrete ◽

Strength Increase ◽

Freeze Thaw

The purpose of this study is to investigate the freeze-thaw resistance, one of the most important durability indicators, of high-performance concrete made of fibers (nylon and polypropylene), AE agent, viscosity agent, and fly ash, an industrial by-product. While FN-1 showed the best freeze-thaw resistance with an about 2.8% relative dynamic modulus of elasticity, PV-2 showed the worst results, with an about 7.4% modulus, in comparison tests with GC. Most of the test samples showed better compressive strength than GC. Especially, N-1 showed the greatest compressive strength increase of 8%. Also, the test samples mixed with FA and PP showed a 2-4% compressive strength increase effect.

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Durability Properties of Concrete Supplemented with Recycled CRT Glass as Cementitious Material

Materials ◽

10.3390/ma14164421 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4421

Author(s):

Dušan Zoran Grdić ◽

Gordana Aleksandar Topličić-Ćurčić ◽

Zoran Jure Grdić ◽

Nenad Srboljub Ristić

Keyword(s):

Compressive Strength ◽

Experimental Testing ◽

Salt Resistance ◽

Sulfate Attack ◽

Mineral Admixtures ◽

Partial Replacement ◽

Concrete Durability ◽

Freeze Thaw ◽

Resistance To Wear ◽

Durability Of Concrete

This paper presents the testing of the durability of concrete where a part of cement was replaced with ground panel cathode ray tube glass (CRT) finer than 63 µm. The percentage of cement replaced with glass is 5%, 10%, 15%, 20%, and 35%, by mass. The highest percent share of mineral admixtures in CEM II (Portland-composiste cement) cement was chosen as the top limit of replacement of cement with glass. In terms of the concrete durability, the following tests are performed: freeze-thaw resistance, freeze-thaw resistance with de-icing salts-scaling, resistance to wear according to the Böhme test, sulfate attack resistance, and resistance to penetration of water under pressure. A compressive strength test is performed, and shrinkage of concrete is monitored. In order to determine the microstructure of concrete, SEM (Scanning Electron Microscopy) and EDS (Energy Dispersive X-ray Spectroscopy) analyses were performed. The obtained research results indicate that the replacement of a part of cement with finely ground CRT glass up to 15% by mass has a positive effect on the compressive strength of concrete in terms of its increase without compromising the durability of concrete. The results obtained by experimental testing unequivocally show that concrete mixtures made with partial replacement (up to 15%) of cement with finely ground CRT glass have the same freeze-thaw resistance, resistance to freeze/thaw with de-icing salt, resistance to wear by abrasion, and resistance to sulfate attack as the reference concrete. In terms of environmental protection, the use of CRT glass as a component for making concrete is also very significant.

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DURABILITY PROPERTIES OF RECYCLED CONCRETE WITH LITHIUM SLAG UNDER FREEZE-THAW CYCLES

Materiali in tehnologije ◽

10.17222/mit.2020.126 ◽

2021 ◽

Vol 55 (2) ◽

pp. 171-181

Author(s):

Yongjun Qin ◽

Jiejing Chen ◽

Ke Liu ◽

Yi Lu

Keyword(s):

Compressive Strength ◽

Modulus Of Elasticity ◽

Dynamic Modulus ◽

Damage Mechanism ◽

Recycled Concrete ◽

Freeze Thaw ◽

Dynamic Modulus Of Elasticity ◽

Thaw Cycle ◽

Freeze Thaw Cycle ◽

Lithium Slag

A water freeze-thaw cycle and sulfate freeze-thaw coupling cycle were explored experimentally to evaluate the durability of recycled concrete with lithium slag (LS). The damage-deterioration law was studied from the aspects of mass-change rate, relative dynamic modulus of elasticity, and cube’s compressive strength. Based on the relative dynamic modulus of elasticity, the damage-degree equation of the concrete was fitted, and a mechanical-attenuation model related to this parameter and the cube’s compressive strength was established and verified. The damage mechanism under the action of the sulfate freeze-thaw cycle was revealed through scanning electron microscopy (SEM). The combination of recycled coarse aggregate (RCA) and LS was beneficial to the anti-deterioration ability of the concrete. During the cycle experiments, the mass and relative dynamic modulus of elasticity increased initially and then decreased, while the cube’s compressive strength declined continually. The concrete with a 30 % RCA substitution rate and 20 % LS exhibited the optimal comprehensive durability, and specimens with excessive LS showed more susceptibility to sulfate erosion. The residual compressive strength of concrete structures can be evaluated by measuring the relative dynamic modulus of elasticity as the two parameters are ideally correlated.

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