1.University of Science and Technology Liaoning;2.Nanjing University of Aeronautics and Astronautics
旨在缩短硫氧镁水泥（MOSC）的凝结时间，提高MOSC的早期力学性能，以蔗糖作为分散剂，利用不同活性氧化镁（MgO）粉制备MOSC，分析了蔗糖对MOSC凝结时间、水化行为、抗压强度、相组成、微观形貌和孔结构的影响. 结果表明：较活性为65.5%的MgO粉，利用活性为75.0%的MgO粉制备的MOSC凝结时间更短，早期抗压强度更高. 蔗糖作为分散剂更适用于利用高活性MgO粉制备的MOSC，其可在MOSC体系中发挥空间位阻效应，改善MOSC浆体的流动度，延长MOSC的初、终凝时间，抑制Mg(OH)2的生长，降低MOSC孔隙率，提高MOSC的28-d抗压强度. 此外，蔗糖可促进MOSC体系吸收大气中的CO2形成MgCO3晶体.
To shorten the setting time and enhance the early compressive strength of magnesium oxysulfate cement (MOSC), the MOSC was prepared using magnesia (MgO) powder with different activities, and sucrose was used as a dispersing agent. The effect of sucrose on the setting time, hydration behavior, compressive strength, phase composition, microstructure and pore structure of MOSC prepared using MgO powder with different activities was investigated. The results show that, compared with MgO powder with 65.5% hydration activity, the setting time of MOSC prepared using MgO powder with 75.0% hydration activity is shorter and the early compressive strength is higher. Sucrose is a better choice for MOSC prepared using MgO powder with 75.0% hydration activity. The sucrose with sterically hindered effect improves the fluidity of MOSC slurry, prolongs the initial and final setting time, inhibits the formation of Mg(OH)2, reduces the total porosity and enhances the 28-d compressive strength of MOSC. In addition, the addition of sucrose is beneficial for the MOSC system to absorb CO2 in the atmosphere to form MgCO3 crystals.