室外环境下不同尺寸混凝土中膨胀剂的应用效果研究

Research on Application Effect of Expansion Agent in Concrete of Different Sizes in Outdoor Environment

依据结构特点选用适宜的膨胀剂可以降低混凝土开裂风险,提升工程质量。通过分析实际环境下混凝土的温度和应变,研究了钙质膨胀剂(AC)和镁质膨胀剂(MZ)对不同尺寸混凝土温度和应变的影响。结果表明:混凝土尺寸越大,混凝土中心温度越高,降温速率越慢,AC和MZ对不同尺寸混凝土的温度变化进程影响均较小;AC和MZ均能补偿混凝土的收缩,随着混凝土尺寸的增加,AC补偿收缩量降低,MZ补偿收缩量增加,其中混凝土尺寸为500 mm时AC的补偿收缩效果更好,1500 mm时AC和MZ补偿的收缩量相差不大,3000 mm时MZ的补偿收缩效果更好。

According to the characteristics of concrete,the selection of appropriate expansion agent can reduce the risk of concrete cracking and improve the quality of the project.By analyzing the temperature and strain of concrete in the actual environment,the influence of calcium expansion agent(AC)and magnesium expansion agent(MZ)on the temperature and strain of concrete of different sizes was studied.The results show that,the larger the size of the concrete,the higher the temperature at the center of the concrete and the slower the cooling rate.AC and MZ have less influence on the temperature change process of different sizes of concrete;both AC and MZ can compensate for the shrinkage of the concrete,as the size of the concrete increases,AC compensation shrinkage is reduced,MZ compensation shrinkage is increased,among which AC compensation shrinkage is more effective under 500 mm size,AC and MZ compensation shrinkage is not much different under 1500 mm size,and MZ compensation shrinkage is more effective under 3000 mm size.