37种试剂对木材-水泥混合物水化的影响

利用改进的sandermann方法评价了37种化学试剂对木材-水泥混合物水化过程的促进作用。根据实验结果,将所用试剂分为两类:第Ⅰ类试剂可使木材-水泥混合物具有与纯水泥相似的水化温度曲线,当试剂加入量为水泥重量的4％时,CaCl_2,SnCl_2及Zn(NO_3)_2可使混合物的最高水化温度达到54.3～48.5℃,是有效的促凝剂;第Ⅱ类试剂使到达最高水化温度的时间提前,在加水后半小时内出现,以二乙醇胺的效果最好,其最高水化温度达50.3℃,对试剂的促凝作用机理提出了初步解释。

Influence of 37 Chemicals on the Hydration of Wood-Cement Mixtures

The ability of 37 chemicals to overcome the inhibition effect of birch dust on the hydration rate of ordinary Portland cement 425~# was investigated by measuring hydration temperature. The compounds tested were divided into two types dependent on the shape of hydration temperature curve over 24 hours. The cement-wood mixture with each of 13 chemicals included in type I produced a two-peak temperature curve similar to that of neat cement. CaCl_2, SnCl_2 and Zn(No_3)_2 reached the highest temperature (54.3～48.5℃).In type Ⅱ, were included 24 compounds in which the mixture offered only a one-peak hydration temperature curve. Ten of the compounds caused an obvious increase of rtempeature at the beginning of the reaction. The most significant effect produced was with the addition of diethanolamine. Based on the results of the study, an explanation is given of the interaction between the chemicals and cement-wood mixture.