新型抗水氯氧镁水泥防渗渠在自然环境的水化产物、相转变规律及其对强度的影响

The Hydration Product Phase Transition Rule and its Influence on the Strength of a New Type of Water-resistant Magnesium Oxychloride Cement Cut-off in Natural Environment

氯氧镁水泥(Magnesium oxychloride cement,MOC)具有快凝、早强、高强、防火和不腐蚀玻璃纤维等优点,非常适合于制作玻璃纤维增强薄壁制品,在农业灌溉工程中具有良好的应用前景。采用XRD和TOPAS分析了新型抗水氯氧镁水泥制成内蒙古防渗渠的物相组成,探讨了氯氧镁水泥制品在自然环境的水化产物与相转变规律、以及相组成对强度的影响。结果表明,在水分缺少的条件下,氯氧镁水泥的水化产物主要为5Mg(OH)_(2)·MgCl_(2)·8H_(2)O(5·1·8)和Mg(OH)_(2);在水分充足的条件下,水化产物主要为Mg(OH)_(2)和5·1·8,碳化产物为碳化氯氧化镁Mg(OH)_(2)·MgCl_(2)·2MgCO_(3)·6H_(2)O(1·1·2·6)和水菱镁矿4MgCO_(3)·Mg(OH)_(2)·4H_(2)O(4·1·4)。水化产物对强度有促进作用,而碳化产物会降低强度。通过10年的工程环境考验,证明新型氯氧镁水泥制品在环境中能够保持主要强度相5·1·8的稳定性,具有良好的长期力学性能。

Magnesium oxychloride cement(MOC)has the advantages of early strength,high strength,fire prevention and non-corrosion of glass fiber.It is very suitble for making glass fiber reinforced thin-walled products and has good application prospect in agricultural irrigation engineering.In this paper,XRD and TOPAS are used to analyze the phase composition of the new type of water-resistant magnesium oxychloride cement made into the Inner Mongolia anti-seepage canal,and the hydration products and phase transition law of magnesium oxychloride cement products in the natural environment,as well as the influence of phase composition on the strength are discussed.The results showed that the hydration products of magnesium oxychloride cement were mainly 5Mg(OH)_(2)·MgCl_(2)·8H_(2)O(5·1·8)and Mg(OH)_(2)under the condition of lack of water.Under the condition of sufficient moisture,the hydration products are mainly Mg(OH)_(2),5·1·8,and the carbonization products are magnesium chloride oxide Mg(OH)_(2)·MgCl_(2)·2MgCO_(3)·6H_(2)O(1·1·2·6)and hydromagnesite 4MgCO_(3)·Mg(OH)_(2)·4H_(2)O(4·1·4).Hydration products promote strength while carbonation products reduce it.