Water Resistance Modification of Magnesium Oxychloride Cement with H3PO4/Na2O·xSiO2·nH2O

2019 ◽  
Vol 814 ◽  
pp. 393-398
Author(s):  
Tian Ben Fan ◽  
Ya Fei Hao ◽  
Ling Xiao Li ◽  
Feng Qing Zhao
Keyword(s):  
Water Resistance ◽  
Moisture Absorption ◽  
Low Cost ◽  
Cost Effective ◽  
High Mechanical Strength ◽  
Magnesium Oxychloride ◽  
Magnesium Oxychloride Cement ◽  
Softening Coefficient ◽  
Hydrolysis Of ◽  
Oxychloride Cement

Magnesium oxychloride cement (MOC) possesses rapid hardening, high mechanical strength, abrasion resistance, low alkali and low corrosive performances. However, its disadvantages of poor water resistance, easily deformation, moisture absorption and halogenations limit the application. A low cost-effective modifier H3PO4/Na2O·xSiO2·nH2O was designed for MOC system. The results showed that the softening coefficient of the modified MOC reaches 0.988 by adding appropriate dosage of the modifier. Gelatinous substances in the modified MOC was produced after soaking in water, which effectively inhibit the hydrolysis of phase 5 (5Mg (OH)2·MgCl2·8H2O) and the formation of Mg (OH)2, thus improving the water resistance of MOC system. Keywords: Magnesium oxychloride cement; Water resistance; Phosphoric acid

scholarly journals Study on Preparation and Properties of Intrinsic Super-Hydrophobic Foamed Magnesium Oxychloride Cement Material

2020 ◽  
Vol 10 (22) ◽  
pp. 8134
Author(s):  
Jiaxin Huang ◽  
Shaojin Ge ◽  
Hongning Wang ◽  
Ruoyu Chen
Keyword(s):  
Compressive Strength ◽  
Absorption Rate ◽  
Water Resistance ◽  
Moisture Absorption ◽  
Engineering Application ◽  
Chemical Corrosion ◽  
Cement Material ◽  
Magnesium Oxychloride ◽  
Magnesium Oxychloride Cement ◽  
Oxychloride Cement

As we all know, magnesium oxychloride foamed cement material has poor water resistance, leading to a decline in application value. In our research, tetraethylorthosilicate (TEOS) and triethoxy-1H, 1H, 2H, 2H-tridecylfluoro-n-octylsilane (FAS) were pre-cohydrolyzed to prepare the overall super hydrophobic magnesium oxychloride cement (MOC) foamed material, and its structure and performances were systematically studied. The results show that adding organosilane can make it have overall hydrophobicity under the premise of maintaining the compressive strength. Mechanical abrading and chemical corrosion tests show its good engineering durability. The maximum moisture absorption rate dropped by 16.2%, and the quality can be restored to 98.1% of the original quality after dehumidification. All these properties show that the hydrophobic foamed magnesium oxychloride cement has potential engineering application value.

Effect of hydroxyacetic acid on the water resistance of magnesium oxychloride cement

2020 ◽  
Vol 246 ◽  
pp. 118428 ◽  
Author(s):  
Xueru Luo ◽  
Wenqiang Fan ◽  
Chunqing Li ◽  
Yong Wang ◽  
Hongjian Yang ◽  
...  
Keyword(s):  
Water Resistance ◽  
Magnesium Oxychloride ◽  
Magnesium Oxychloride Cement ◽  
Hydroxyacetic Acid ◽  
Oxychloride Cement

Experimental Study on Desulfurized Gypsum Modified Magnesium Oxychloride Cement

2011 ◽  
Vol 236-238 ◽  
pp. 1554-1558
Author(s):  
Zhi Jie Zhang ◽  
Tao Li ◽  
Ping An Liu
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Abrasion Loss ◽  
Magnesium Oxychloride ◽  
Abrasive Tools ◽  
Magnesium Oxychloride Cement ◽  
Softening Coefficient ◽  
Oxychloride Cement

The influences of desulfurization gypsum on the properties of both Magnesium oxychloride cement (MOC) pastes and MOC abrasive tools were investigated in this study. By incorporating desulfurization gypsum in the MOC pastes, the compressive strength of MOC paste improved slightly. With 5% gypsum addition, the flexural strength of MOC pastes increased by 36%, the abrasion loss of MOC abrasive tools decreased by 35%, the strength softening coefficient greatly increased. The mechanism maybe due to the microstructure of the MOC pastes became more compact with gypsum adding, the rate of hydrolyzation reaction of MOC phases would be postponed.

Influence of Calcium Added Slag on the Strength and Water-Repellency of Magnesium Oxychloride Cement

2013 ◽  
Vol 278-280 ◽  
pp. 437-439
Author(s):  
Yu Jie Jin ◽  
Li Guang Xiao ◽  
Feng Luo
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Water Repellency ◽  
Magnesium Oxychloride ◽  
Magnesium Oxychloride Cement ◽  
Softening Coefficient ◽  
Oxychloride Cement

The influence of dosage of calcium added slag on the strength and water-repellency of Magnesium oxychloride cement was studied in this paper. The results indicated that the compressive strength of magnesium oxychloride cement enhanced while the flexural strength remained unchanged when the dosage of calcium added slag between 5%-30%. The compressive strength of magnesium oxychloride cement was 110.0 MPa when the dosage of Calcium added slag was 20%, which increased the strength of 17%. The calcium added slag significantly improved the water-repellency of Magnesium oxychloride cement. The softening coefficient of magnesium oxychloride cement was more than 0.82, and the highest is 1.07.

Influence of Admixture on the Properties of Magnesium Oxychloride Cement

2013 ◽  
Vol 662 ◽  
pp. 402-405
Author(s):  
Yu Jie Jin ◽  
Li Guang Xiao ◽  
Feng Luo
Keyword(s):  
Phosphoric Acid ◽  
Water Repellency ◽  
Magnesium Oxychloride ◽  
Magnesium Oxychloride Cement ◽  
Softening Coefficient ◽  
Oxychloride Cement

The influence of phosphoric acid and iron vitriol on the properties of magnesium oxychloride cement is studied in this paper. The experiment indicated that phosphoric acid and iron vitriol can improve the water-repellency of magnesium oxychloride cement. The softening coefficient is about 1.014 when the dosage of phosphoric acid is 1% and the softening coefficient is about 0.77 when the dosage of iron vitriol is 4%.

Magnesium Oxychloride Cement Modified by Aluminum-Leached Coal Fly Ash

2012 ◽  
Vol 174-177 ◽  
pp. 1026-1029 ◽  
Author(s):  
Cheng You Wu ◽  
Hui Fang Zhang ◽  
Hong Fa Yu
Keyword(s):  
Fly Ash ◽  
Compression Strength ◽  
Water Resistance ◽  
Coal Fly Ash ◽  
Filling Material ◽  
High Compression ◽  
Magnesium Oxychloride ◽  
Magnesium Oxychloride Cement ◽  
Ash Residue ◽  
Oxychloride Cement

Effects of aluminum-leached coal fly ash residue on water-resistance, compression strength and efflorescence of MOC cement have been investigated. The results show that the compression strength of MOC cement curried for 28 days increases with the dosage of ACFAR. The water resistance of MOC cement can be improved obviously. This study has proved that aluminum-leached coal fly ash residue can be used as the filling material of MOC cement with high compression strength and good water-resistance.

Improved Magnesium Cement for Durable Hemp Composite Boards

2022 ◽  
Author(s):  
Jelizaveta Zorica ◽  
Maris Sinka ◽  
Genadijs Sahmenko ◽  
Diana Bajare
Keyword(s):  
Compressive Strength ◽  
Water Resistance ◽  
Chemical Reactivity ◽  
Ease Of Use ◽  
Lower Amount ◽  
Insulation Material ◽  
Magnesium Oxychloride ◽  
Magnesium Oxychloride Cement ◽  
Cement Board ◽  
Oxychloride Cement

Hemp concrete is a well-known bio-based building material, but due to its relatively low compressive strength is mainly used as an insulation material with a load-bearing wooden frame. There are possibilities to expand hemp concrete application in construction by substituting traditional lime with magnesium cement. Magnesium oxychloride cement is a material already known for some time and nowadays used in building board production. Strength, lightweight, ease of use are advantages that highlight relatively new magnesium oxychloride type boards compared to traditional sheeting materials such as plywood, gypsum plasterboard and fibre-cement board. Therefore, similar parameters are thought to be reached by producing magnesium oxychloride hemp board. In this work, magnesium cement water resistance was studied and possibilities to improve it was examined by adding fly ash and nanosilica. Among the nanomaterials used in building materials, nanosilica has gained significant interest by performing a beneficial effect in improving the mechanical properties of concretes. In addition, due to its ultrafine size and high chemical reactivity, the performance of nanosilica is much better with a lower amount of admixture required. Results show that applied nanosilica slightly reduced the compressive strength of magnesium cement in a dry state, but at the same time significantly increased its water resistance. Hemp magnesium oxychloride cement board prototype samples were produced and demonstrate promising results for further manufacturing of hemp composite boards.

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