JM-Ⅱ外加剂在某高层建筑施工中的应用

在高层钢筋混凝土结构工程中，混凝土性能的优异是确保工程质量的前提。混凝土外加剂用量虽少，但其对混凝土性能影响较大。结合JM—Ⅱ外加剂在某高层建筑施工中的实例，通过试验，研究JM—Ⅱ外加剂的不同掺量对混凝土的和易性、抗压强度、含气量、坍落度损失、凝结时间、泌水率、水化热等性能的影响，同时研究JM—Ⅱ外加剂在不同水灰比情况下，对混凝土的抗渗、抗冻等耐久性的影响。结果表明，JM—Ⅱ外加剂能使混凝土便于浇灌且提高强度，降低水化热，显著提高混凝土的抗渗、抗冻等耐久性能。

The Application of JM-Ⅱ Admixture to the Construction of High-storeyed Buildings

For high-storeyed projects of reinforced concrete structure, the good performance of reinforced concrete is the prerequisite that guarantees their quality. Although the amount of reinforced concrete admixture used in engineering projects is small, it exerts a great influence on concrete performance. A case study is made in this paper on the application of JM-II admixture to a high-storeyed building. Tests are made to obtain the effect of different admixture amounts on the concrete's coagulation, compressive strength, air content, loss of collapse, coagulation time, water secreting rate, the heat of hydration and other parameters. Besides, research is made into the effect of JM-II admixture on the imperviousness and anti-freezing property of concrete in accordance with the differences in water-dust proportions. Results indicate that the application of JM-II admixture can obtain excellent effects. It makes the concrete easy to water, improves its intensity, reduces the heat of hydration and upgrades its impervious and anti-freezing durability.