scholarly journals Influence of Super Absorbent Polymer on the Sulfate Resistance of Cement Mortar

2021 ◽  
Vol 2101 (1) ◽  
pp. 012076
Author(s):  
Meiyan Hang ◽  
Yubin Yang ◽  
Minghui Jiang ◽  
Chenggong Wang ◽  
Teng Cheng ◽  
...  

Abstract Structures are easily corroded in the Salt Lake areas of China, especially in sulfate solution. This study was intended to settle the problem of sulfate corrosion failure of concrete structures, the influences of different contents of super absorbent polymer (abbreviated as SAP) on the working performance, mechanical properties, corrosion resistance and expansion performance of cement mortar were studied. The mechanism of SAP in mortar was analyzed and studied by SEM. The results showed that although SAP could slightly decrease the fluidity and strength of cement mortar, but it could remarkably improve the coefficient of resistance erosion of specimens and the inflation coefficient of cement paste. When the content of SAP was 0.3%, the sulfate corrosion resistance and expansion performance of specimens showed the best (the coefficient of resistance erosion and inflation coefficient of mortar specimens were 0.95 and 0.97, respectively). Besides, SAP could release much water in the hydration process, form irregular holes, and increase the porosity of mortar specimens. There would more hydration products generated and filled in the pores during the hydration process, thereby improving the sulfate resistance of mortar specimens. Therefore, this research provides theoretical guidance and basis for the study of sulfate corrosion damage of concrete structures in the future.

2011 ◽  
Vol 477 ◽  
pp. 200-204 ◽  
Author(s):  
Lu Feng Pang ◽  
Shi Ye Ruan ◽  
Yong Tao Cai

This paper focuses on the shrinkage of concrete, influenced by the different mixing amount of super absorbent polymer—SAP and extra-water. The experiment showed that the SAP-cement-mortar shrinkage is reduced greatly by mixing SAP. Extra-water can improve the function of reducing shrinkage of SAP. When the amount is 20, the shrinkage is lest, account for 57% of blank group’s. The SAP has well effect on the cement mortar shrinkage. Besides, we found that the strength of this group account for 89% of blank group. So the proper amount of SAP and extra-water has poorly influence on the strength of concrete.


2020 ◽  
Vol 6 (11) ◽  
pp. 2231-2244
Author(s):  
Md Mahfuzur Rahman ◽  
Laila Tul Zannat Jyoti ◽  
Snahashish Paul ◽  
Al- Ishmam ◽  
Md Akhtar Hossain

Super Absorbent Polymer (SAP) is a favorable admixture which can influence various properties of cementitious materials. It mainly improves the water retaining properties of cement-based construction materials. In this paper, an experimental program was carried out to determine the mechanical and thermal performance of cement plaster containing SAP. Firstly, the absorption capacity of SAP was determined in different loading conditions and chloride solutions. Thereafter, the optimum dosage of SAP for cement plaster was also determined from five different proportions of SAP (0.05, 0.1, 0.3, 0.5 and 1% of cement mass) based on the compressive strength test results. The mortar incorporating 0.05% SAP of cement mass was selected as the optimum dosage, which yielded the highest compressive strength. Two slabs of 1×1×25 mm with 0.05% SAP and two slabs of 1×1×25 mm without SAP were cast to determine the thermal performance of the cement mortar with and without SAP. For this purpose, a wooden chamber of 2×1×1 m was constructed and the slab was placed in the middle of this chamber to carry out the thermal performance test of cement mortar. The slabs with 0.05% SAP showed promising results for acting as a thermal barrier in buildings compared to slabs without SAP. Doi: 10.28991/cej-2020-03091614 Full Text: PDF


2014 ◽  
Vol 501-504 ◽  
pp. 2116-2119 ◽  
Author(s):  
Shuang Jun Xing ◽  
Hai Chao Fan ◽  
Jun Zheng ◽  
Bin Jun Guan

Through the mechanical properties experiments and analyses of ordinary marine concrete and marine concrete with fly ash added, it was thought that the proper content of SAP added could release free water for cement particles to continue hydrating during the curing stage, guarantee adequate water. So, SAP could significantly improve the performances of marine concrete. As to marine concrete with fly ash added, because part of fly ash took part in hydration process of cement particles and another part filled in gap structure of concrete, the appropriate content of SAP added was different from ordinary marine concrete and it should be according to the amount of fly ash added.


2020 ◽  
Vol 25 (2) ◽  
pp. 66-71
Author(s):  
A.B. Drovosekov

Corrosion resistance properties, such as porosity, stability in the atmosphere of NaCl mist, and anodic electrochemical activity in a sulfuric acid solution are studied and compared for Ni-W-P and Ni-P coatings obtained by electroless deposition. The studied coatings were obtained from solutions with glycine as the main ligand and contained 10.2 to 15.6 at.% of phosphorus and up to 3.3 at.% of tungsten. It is shown that Ni-W-P coatings with a tungsten content of 2.3 to 3.3 at.% and a thickness of 15 μm have a significantly lower porosity as compared with nickel-phosphorus coatings of the same thickness. Also, significantly better stability of Ni-W-P coatings in a NaCl mist atmosphere was observed, their corrosion damage degree is less than that of Ni-P coatings, and relatively little depends on the duration of exposure in a corrosive environment. Analysis of anodic polarization curves showed an almost similar electrochemical activity upon dissolution of Ni-P and Ni-W-P coatings in sulfuric acid. Both these types of electroless coatings showed a markedly better tendency to anodic dissolution than pure nickel. Taking into account the obtained experimental data, a conclusion is made as to the better protective characteristics of Ni-W-P coatings in comparison with nickel-phosphorus coatings. The main reason of the inferior protective properties of Ni-P coatings is their relatively high porosity.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 543
Author(s):  
Ketan Kumar Sandhi ◽  
Jerzy Szpunar

Nickel superalloy Hastelloy-N, alloy X-750, stainless steel 316 (SS316), and stainless steel 304 (SS304) are among the alloys used in the construction of molten salt reactor (MSR). These alloys were analyzed for their corrosion resistance behavior in molten fluoride salt, a coolant used in MSR reactors with 46.5% LiF+ 11.5% NaF+ 42% KF. The corrosion tests were run at 700 °C for 100 h under the Ar cover gas. After corrosion, significant weight loss was observed in the alloy X750. Weight loss registered in SS316 and SS304 was also high. However, Hastelloy-N gained weight after exposure to molten salt corrosion. This could be attributed to electrochemical plating of corrosion products from other alloys on Hastelloy-N surface. SEM–energy-dispersive X-ray spectroscopy (EDXS) scans of cross-section of alloys revealed maximum corrosion damage to the depth of 250 µm in X750, in contrast to only 20 µm on Hastelloy-N. XPS wide survey scans revealed the presence of Fe, Cr, and Ni elements on the surface of all corroded alloys. In addition, Cr clusters were formed at the triple junctions of grains, as confirmed by SEM–EBSD (Electron Back Scattered Diffraction) analysis. The order of corrosion resistance in FLiNaK environment was X750 < SS316 < SS304 < Hastelloy-N.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 663
Author(s):  
Jung Soo Kim ◽  
Dong Hyun Kim ◽  
Youn Suk Lee

In this study, a superabsorbent polymer (SAP) comprising poly (IA-co-cellulose-co-VSA-co-AA; ICVA) core-SAP (CSAP) was synthesized through radical polymerization using itaconic acid (IA), acrylic acid (AA), cellulose, and vinyl sulfonic acid (VSA) as monomers. The absorption performances and relative biodegradability of various compositions prepared by adjusting the amounts of cellulose and VSA with constant IA and AA content were compared. Increasing the cellulose content in CSAP contributed to improved biodegradation of the surface-crosslinked SAP (SSAP) and gel strength, although the free absorbency (FA) and centrifuge retention capacity (CRC) decreased. Increasing the VSA content resulted in strong anionicity, which enables the absorption of large amounts of water. Surface-crosslinking technology was applied to the CSAP synthesized with the optimal composition ratio to increase its absorption performance and gel strength. Improved performance of the synthesized SSAP (a CRC of 30.4 g/g, absorbency under load (AUL) of 23.3 g/g, and permeability of 55 s) was achieved by selecting the optimal surface-crosslinking treatment time and the amount of distilled water in the surface-crosslinking solution: as the latter was increased in the surface-crosslinking solution, the AUL and permeability of the SSAP were improved, and its biodegradability was found to be 54% compared to the 100% biodegradable cellulose hydrogel in the control group.


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