Standard specification for water vapor retarders used in contact with soil or granular fill under concrete slabs 混凝土板下土壤或粒状填料接触的水蒸气缓凝剂用标准规范
The paper studies on the principal technologies on coal desulfurization and retardant mechanism of cement retarder and active mechanism of cement mixed material 摘要介绍了煤炭脱硫产物和它们作水泥缓凝剂、水泥混合材的研究。
In this paper , the effects of common set - retarders and early - age curing on properties of concrete are studied so as to control the quality of concrete 为此，本论文研究了常用缓凝剂和早期养护条件对混凝土性能的影响，以期对混凝土工程质量控制具有一定的指导作用。
Three kinds of grout with phosphate as their retarder are screened out by orthogonal experiment according to engineering requirement . their performance and feature are introduced 针对工程实际的要求，筛选了以磷酸盐为缓凝剂的3种类型的注浆浆液，采用正交法进行试验研究，并介绍了它们各自的性能特点。
The effects of various set - retarders on strength of concrete are different . 28 - day strength of concrete decrease in different degree with amount of ca - lignosulphonate , ca - solassate and sucrose increase 常用缓凝剂对混凝土强度的影响差异较大，木钙、糖钙和蔗糖掺量过大，混凝土28d强度都有不同程度的下降。
Furthermore , by testing the supersaturation of liquid phase , hydration rate , hydration temperature as hydration of gypsum with the retarders , the effect of retarders on the hydration process is found out 通过对掺加缓凝剂后对石膏水化过程中的液相过饱和度、水化率和水化温度的测试，了解缓凝剂对石膏水化进程的影响。
The effects of five common set - retarders on setting time of cement paste and concrete and strength of concrete are studied . to cement paste , amount of set - retarders added in cement has a critical value 论文分别研究了木钙、糖钙、酒石酸、焦磷酸钠和蔗糖共五种常用缓凝剂对水泥净浆凝结时间、混凝土凝结时间及强度的影响。
Results of experiment show that the reason of strength decreasing of gypsum added with retarders is that the retarders reduce the supersaturation of liquid phase , and makes the crystal grain largen , and pore is followed to worsen , which lead to the strength drop to a large degree 实验结果分析表明：在掺加缓凝剂后石膏硬化体强度下降的原因在于缓凝剂降低了石膏的液相过饱和度，使结晶颗粒变大，使石膏的孔结构恶化，最终导致了宏观强度大幅度下降。
The scanning electron micrographs and the data of pore structure of gypsum and gypsum with the retarders also make us known the influence of retarders on the crystal morphology and pore structure , from which transformation of microstructure induced by retarders and the reason of which makes the strength drop a re analyzed . combined with the xps spectrum , the mechanism of action with the retarders are finally proposed 继而通过对孔结构和石膏硬化体晶体扫描电镜照片的观测，获得缓凝剂对石膏硬化体晶体形貌的影响和对孔结构的改变的信息，分析缓凝剂的带来石膏的微结构的变化，以及掺加缓凝剂带来石膏强度下降的原因所在。
