沸石岩火山灰活性的研究

STUDIES ON POZZOLANIC ACTIVITY OF ZEOLITE-TUFF

用化学的、物理的和物化的方法证明 ,沸石凝灰岩中的沸石是热力学稳定的物质 ,硅酸盐水泥中碱度在常温下不足以破坏沸石的结构。沸石凝灰岩的火山灰活性来自凝灰岩中无定性的SiO2 和Al2 O3。含有结晶态沸石的凝灰岩之所以有比非晶态火山灰高的活性 ,是因为沸石特殊的结构所起的“水气交换”作用以及其晶体颗粒调节浆体中微结构的作用。沸石含量不同的沸石凝灰岩在水泥中的掺量以 5 %～ 2 0 %为宜 。

By experiment of chemical, physical and physical chemistry method, it is proved that zeolite in tuff is stable in thermodynamics. Structure of zeolite cannot be destroyed by alkalinity in portland cement paste at normal temperature, pozzolanic activity of zeolite_tuff is from amorphous SiO 2 and Al 2O 3 therein. What activity of tuff containing crystalline zeolite is higher than that of uncrystalline materials is because of function of water-air exchange by the special structure of zeolite as well as effect of adjusting grading of micro-grain by crystalline zeolite. The suitable blended amount of zeolite_tuff in cement is 5%-20% depending on zeolite content in tuff. The suitable type of zeolite in tuff used for portland cement is clinoptilolite or mordenite of calcium_type and sodium_type.