Chloride resistance of concrete containing nanoparticle-modified polymer cementitious coatings

2021 ◽  
Vol 299 ◽  
pp. 123736
Author(s):  
Guo Li ◽  
Yi Ding ◽  
Tianyu Gao ◽  
Yiming Qin ◽  
Yajun Lv ◽  
...  
Keyword(s):  
Modified Polymer ◽  
Chloride Resistance

scholarly journals Improvements of Nano-TiO2 on the Long-Term Chloride Resistance of Concrete with Polymer Coatings

Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 323 ◽  
Author(s):  
Guo Li ◽  
Hangyuan Cui ◽  
Jiacheng Zhou ◽  
Weijian Hu
Keyword(s):  
Accelerated Aging ◽  
Polymer Coatings ◽  
Coating Films ◽  
Nano Tio2 ◽  
Modified Polymer ◽  
Chloride Resistance ◽  
Before And After ◽  
Electric Flux ◽  
Ultraviolet Aging

The long-term chloride resistance of concrete treated with nano-TiO2-modified polymer coatings was studied. Three types of organic film-forming paints: polyurethane, epoxy resin, and chlorinated rubber were selected, and concrete specimens with nano-TiO2-modified coatings were fabricated. Then, specimens were subjected to periodical ultraviolet-accelerated aging and subsequent Coulomb electric flux experiments. Nanomodified coatings before and after ultraviolet aging were observed through scanning electron microcopy. Results indicate that the nano-TiO2 particles can effectively reduce the microdefects in coating films and alleviate damages due to aging. As a result, nano-TiO2 can significantly reduce the Coulomb fluxes of coated concrete before and after coating aging, and the average reduction amplitudes reached 66% and 44%. That is, nano-TiO2 can remarkably improve the long-term chloride resistance of coated concrete. In addition, we established the development models of the ultraviolet aging and chloride resistance of coated concrete according to an S-shaped curve.

Physical and technological basics and new generation technology of radiation- modified polymer concrete

2015 ◽  
Vol 37 (0) ◽  
pp. 116-122
Author(s):  
T. V. Kovalinska ◽  
А. G. Zelinskyi ◽  
V. I. Sakhno ◽  
О. М. Fainleib ◽  
D. Yu. Kolesnik ◽  
...  
Keyword(s):  
Polymer Concrete ◽  
Modified Polymer ◽  
New Generation ◽  
Generation Technology

scholarly journals Experimental Study and Simulation Calculation of the Chloride Resistance of Concrete under Multiple Factors

2021 ◽  
Vol 11 (12) ◽  
pp. 5322
Author(s):  
Yang Ding ◽  
Tong-Lin Yang ◽  
Hui Liu ◽  
Zhen Han ◽  
Shuang-Xi Zhou ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Penetration Depth ◽  
Chloride Ion ◽  
Cementitious Materials ◽  
Chloride Ions ◽  
Finite Element Software ◽  
Chloride Resistance ◽  
Simulation Calculation ◽  
Marine Concrete ◽  
Resistance Performance

Cement is widely used in marine concrete, and its resistance to chloride ion corrosion has been widely considered. In this paper, based on a laboratory test, the influence of different hydrostatic pressures, coarse aggregate contents and w/c ratios on the chloride resistance performance is analyzed. Based on COMSOL finite element software, a two-dimensional cementitious materials model is established, and the simulation results are compared with the experimental results. The results show that the penetration depth of chloride ions in cement increases with the increase of the w/c ratio. Under the hydrostatic pressure of 0 MPa, when the w/c ratio is 0.35, the penetration depth of chloride ions is 7.4 mm, and the simulation result is 8.0 mm. When the w/c ratio is 0.45, the penetration depth of chloride ions is 9.3 mm, and the simulation result is 9.9 mm. When the w/c ratio is 0.55, the penetration depth of chloride ions is 12.9 mm, and the simulation result is 12.1 mm. Under different hydrostatic pressures, the penetration depth of chloride ions obviously changes, and with the increase in hydrostatic pressure, the penetration depth of chloride ions deepens. Under the w/c ratio of 0.35, when the hydrostatic pressure is 0.5 MPa, the penetration depth of chloride ions is 11.3 mm, and the simulation result is 12.1 mm. When the hydrostatic pressure is 1.0 MPa, the penetration depth of chloride ions is 16.2 mm, and the simulation result is 17.5 mm.

scholarly journals Surface modification of YS-20 with polydopamine for improving the tribological properties of polyimide composites

Friction ◽  
2021 ◽  
Author(s):  
Liangfei Wu ◽  
Zhaozhu Zhang ◽  
Mingming Yang ◽  
Junya Yuan ◽  
Peilong Li ◽  
...  
Keyword(s):  
Polymer Composites ◽  
Tribological Properties ◽  
Metallic Copper ◽  
Great Effort ◽  
Modified Polymer ◽  
Milling Method ◽  
Multi Walled Carbon Nanotubes ◽  
Mixing Method ◽  
Walled Carbon Nanotubes ◽  
Polymer Powders

AbstractRecently, great effort has been devoted to prepare various reinforce fillers to improve polymer performances, but ignoring the importance of raw polymer powders which are indispensable parts of hot-pressed polymer composites. Herein, we engineer raw polyimide (PI) powders with the assistance of polydopamine (PDA) in aqueous solutions. After the modification, polymer powders change from hydrophobic to hydrophilic, which makes it is possible to further modification of polymer powders in liquid phase. During the curing process of modified polymer powders, the partial dehydration of the catechol groups and crosslinking of PDA via C-O-C bonds are confirmed. Based on the features of PDA, a non-destructive mixing method is utilized to realize homogeneous dispersion of multi-walled carbon nanotubes (MWCNTs) in polymer matrix. In comparison with ball milling method, this way can preserve the integrated innate structure of MWCNTs effectively. Besides, by taking full advantage of the reducing and metal-coordination capability of PDA, Cu2+ is successfully loaded onto the surfaces of polymer powders. The related characterizations demonstrate that Cu2+in situ converts to metallic copper rather than copper oxide during the hot pressing process. The tribological properties of corresponding polymer composites are also studied. These results indicate that modifying polymer powders with PDA is multi-profit and presents practical application prospect.

High selective gas sensors based on surface modified polymer transistor

2021 ◽  
Vol 91 ◽  
pp. 106083
Author(s):  
Ruxin Song ◽  
Xu Zhou ◽  
Zi Wang ◽  
Lunan Zhu ◽  
Jie Lu ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Modified Polymer ◽  
Surface Modified

scholarly journals Enhancing carbonation and chloride resistance of autoclaved concrete by incorporating nano-CaCO3

2020 ◽  
Vol 9 (1) ◽  
pp. 998-1008
Author(s):  
Guo Li ◽  
Zheng Zhuang ◽  
Yajun Lv ◽  
Kejin Wang ◽  
David Hui
Keyword(s):  
Cement Hydration ◽  
Mercury Intrusion Porosimetry ◽  
Hardened Concrete ◽  
Optimal Dosage ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Carbonation Depth ◽  
X Ray ◽  
Chloride Resistance

AbstractThree nano-CaCO3 (NC) replacement levels of 1, 2, and 3% (by weight of cement) were utilized in autoclaved concrete. The accelerated carbonation depth and Coulomb electric fluxes of the hardened concrete were tested periodically at the ages of 28, 90, 180, and 300 days. In addition, X-ray diffraction, thermogravimetry, and mercury intrusion porosimetry were also performed to study changes in the hydration products of cement and microscopic pore structure of concrete under autoclave curing. Results indicated that a suitable level of NC replacement exerts filling and accelerating effects, promotes the generation of cement hydration products, reduces porosity, and refines the micropores of autoclaved concrete. These effects substantially enhanced the carbonation and chloride resistance of the autoclaved concrete and endowed the material with resistances approaching or exceeding that of standard cured concrete. Among the three NC replacement ratios, the 3% NC replacement was the optimal dosage for improving the long-term carbonation and chloride resistance of concrete.

scholarly journals Preliminary Study on the Utilization of RHA as a Performance Enhancer for Rubber Mortar

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3216
Author(s):  
Jin Li ◽  
Peiyuan Chen ◽  
Haibing Cai ◽  
Ying Xu ◽  
Chunchao Li
Keyword(s):  
Compressive Strength ◽  
Mechanical Strength ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Capillary Absorption ◽  
Optimal Dosage ◽  
Positive Effects ◽  
Waste Rubber ◽  
Chloride Resistance ◽  
Preliminary Study

In this study, rice husk ash (RHA) was explored as a strength enhancer for mortars containing waste rubber. The effects of RHA on the flow, mechanical strength, chloride resistance, and capillary absorption of rubber mortar were investigated by substituting up to 20% cement with RHA. The experimental results showed that the incorporation of rubber into mortar could be safely achieved by adding RHA as a cement substitute by up to 20% without compromising the compressive strength of mortar. Moreover, the RHA also exerted positive effects on the enhancement of the chloride resistance as well as the capillary absorption of rubber mortars, for which 15% RHA was found to be the optimal dosage.

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