【作者】 张向华；

【导师】 陈吉春；

【作者基本信息】 武汉理工大学 ， 环境工程， 2007， 硕士

【摘要】 我国硬石膏资源非常丰富。近年来，国内外对于硬石膏的胶凝性能的研究已经取得较大突破，从而为资源丰富的硬石膏应用于更多领域提供了可能。硬石膏制品是一种多孔材料，吸水能力非常强。石膏硬化体中吸收的水分会使结晶接触点发生溶解和再结晶，从而导致石膏制品强度降低。论文以降低硬石膏制品吸水率为研究目标，旨在提高硬石膏制品的强度，扩大硬石膏的应用范围。论文首先以液体石蜡和松香为原料，采用聚氧化乙烯(20)失水山梨醇单月桂酸酯(吐温20)和失水山梨醇单油酸酯(斯盘80)作为乳化剂，十二烷基苯磺酸钠(SDBS)作为助乳剂，通过正交实验优化了改性石蜡乳液的制备工艺。在HLB值为11，乳化剂用量15％，搅拌速度600r／min，水油比为3∶1，反应时间为15min，且石蜡和松香按照3∶2的比例在65℃的时候采用常压逆转工艺的条件下，所制备的改性石蜡乳液颜色呈蓝白色，粒径在0.1～1μm之间，粘结力为1350N，并且其粘度较低，仅为0.2Pa·s。以改性石蜡乳液作为防水剂内掺到硬石膏制品中，当剂水比为3∶20时，硬石膏制品的软化系数为0.58，制品吸水率为17.5％，与内掺1∶5的剂水比相比，其软化系数变化不大，而初终凝时间分别下降了为5min和5.5min，即12min和16.5min。可以认为，将改性石蜡乳液作为硬石膏制品的防水剂，不仅可以有效地改善硬石膏制品的防水性能，而且有助于硬石膏胶凝性能的提高。在上述研究的基础上，本文进一步研究了水泥、矿渣、粉煤灰对于硬石膏制品的防水性能及胶凝性能影响。结果表明：水泥、矿渣、粉煤灰对于硬石膏制品的吸水性能的改善是有限的，吸水率仍在20％以上，但制品抗压强度提高很大。当粉煤灰含量为15％，矿渣含量为25％时，制品的软化系数为0.77。这三种成分之所以能够降低硬石膏制品的吸水率并提高其抗压强度，是因为它们都能不同程度的提高硬石膏制品的密实度。更多还原

【Abstract】 The anhydrite resources of our country are very abundant. In recent years, the domestic and international experts have made great break-through on the study of clotted capability of anhydrite, which made it possible for anhydrite to be used in more fields. Anhydrite products are lacunaris materials, proning to absorb water. The water absorbed by anhydrite products can make crystalloid touch point to be dissolved and separated out again, deceasing the intensity of the anhydrite products. The main purpose of this study is to research how to decrease the absorbing water rate of anhydrite products, improve the intensity of anhydrite products and expand the range of application of anhydrite.In this study, liquid paraffin and rosin are used as raw materials, Tween-20 and Span-80 as emulsifier, SDBS as assistant emulsifier. And the synthesis conditions of modified paraffin emulsion is optimized through orthogonal experiments. When the HLB value of emulsifier is 11, the dosage of emulsifier is 15%, the speed of stir is 600r/min, the ratio of water and oil is 3:1, the time of reaction is 15min and paraffin and rosin that is mixed by the ratio of 3:2 are prepared modified paraffin emulsion at 65℃by the techniques of normal air pressure and reversion, we can obtain a kind of emulsion which have the character of a sort of blue and white liquid with the particle diameter range from 0.1 to 1μm, the felting strength of 1350N and the lower viscosity of 0.2Pa·s.Added in as waterproofing agent, modified paraffin emulsion can be joined into anhydrite products. The softening coefficient of anhydrite products is 0.58 and the absorbing water rate of anhydrite products is 17.5% when the ratio of emulsion and water is 3:20. Compared with the ratio of emulsion and water which is 1:5, the softening coefficient of anhydrite products has changed little, but the inchoate and final coagulate time of anhydrite has been reduced for 5min and 5.5min separately, i.e. 12min and 16.5min. So not only the waterproofing capability of anhydrite products can be effectively improved, but also the clotted capability is enhanced, when modified paraffin emulsion is used as waterproofing agent of anhydrite productsThis thesis, based on above research, further studies the effect of cement, slag and pulverous coal on waterproofing capability and clotted capability of anhydrite products. The results show that it is limited for cement slag and pulverous coal to improve waterproofing capability and clotted capability of anhydrite products, since the absorbing water rate of anhydrite products is still above 20%. But the compressive strength of anhydrite products increases greatly. The softening coefficient of anhydrite products is 0.77 when the content of pulverous coal is 15% and the content slag is 25%. These three components can reduce the absorbing water rate of anhydrite products and enhance its intensity, because they can increase the density of anhydrite products in varying degrees.更多还原