两种离子侵蚀抑制剂对水泥水化过程及产物的影响

Effects of two type erosion inhibitors on cement hydration and products

内掺离子侵蚀抑制剂(TIA)抵抗环境腐蚀、离子侵蚀混凝土是提升混凝土耐久性的有效的方法之一,但掺入离子侵蚀抑制剂会降低水泥复合材料基体的强度。通过微量热、X射线衍射、红外光谱、电子显微技术研究了2种TIA对砂浆和净浆的界面、水化程度、水化产物的生成量和水化产物形貌的影响。试验发现,2种TIA均会降低水泥基材料的早期抗压强度。TIA对界面、水化程度和水化产物未产生明显的影响;稀溶液中TIA对水泥水化和氢氧化钙成核生长过程的影响试验发现,羧酸钙优先于氢氧化钙的生成,羧酸钙具有强的疏水性会均匀地分布在水溶液中,羧酸钙会影响不同水化产物之间的搭接;羧酸钙生成的疏松浆体微结构,导致次生应力产生,降低了水泥浆体的开裂应力和极限应力,且抑制剂的碳链越长对微结构负面影响越大。

Erosion inhibitor addition(TIA)to resist environmental corrosion ion attack of concrete is one of the effective methods to improve concrete durability,but the addition of inhibitors will reduce the strength of the cement composite matrix.The effects of two erosion inhibitors on the ITZ,hydration degree,hydration product generation and hydration product morphology of mortar and slurry were studied by calorimetry,X-ray diffraction,infrared spectroscopy and electron microscopy.It has been found that both of inhibitors would reduce the early compressive strength of the cementitious material although they have different influences on the air content.In addition,the inhibitors have no obvious effect on the degree of cement hydration degree,the amount of hydration products and the chemical bond.The effects of TIA on cement hydration and calcium hydroxide nucleation growth process in the dilute solution show that that calcium carboxylate with strong hydrophobicity is prior to the formation of CH which will affect the overlap between different hydration products,the formation of calcium carboxylate loose slurry microstructure,resulting in secondary stress to reduce the ultimate stress.In addition,the longer carbon chains of inhibitors cause the greater negative impact on the microstructure.