【作者】 刘先锋；

【导师】 杨长辉；

【作者基本信息】 重庆大学 ， 材料科学与工程， 2006， 硕士

【摘要】 碱矿渣水泥是用碱金属的碱性化合物激发矿渣(铝硅酸盐组分)形成的胶凝材料,以之为基础的碱矿渣混凝土具有高强、快硬、低水化热、耐久等优良性能。目前,已有研究主要集中在碱矿渣水泥及混凝土的激发剂、耐久性、凝结性能方面,取得了较多成果。但是,这些研究和应用主要基于塑性和低塑性碱矿渣混凝土。通常水胶比条件下,碱矿渣混凝土拌合物粘度大,施工较困难,难以适应现代施工技术的发展,并且成为制约碱矿渣水泥及混凝土应用发展的关键技术。掺用表面活性剂是解决上述问题的重要技术途径之一,但是迄今为止,对表面活性剂在碱矿渣水泥及混凝土中作用机理的系统研究较少。表面活性剂在碱矿渣水泥及混凝土的作用机理研究是确立适合碱矿渣水泥这一特殊胶凝材料专用塑化剂的重要理论基础,对促进其应用具有深远意义。本文通过表面张力、吸附量、动电电位(ζ电位)、水泥净浆流动度试验,分析了表面活性剂品种、掺量、激发剂品种、掺量等对碱溶液表面张力、表面活性剂在矿渣表面的吸附量、矿渣颗粒动电电位和碱矿渣净浆流动性的影响。以此对表面活性剂在碱矿渣水泥系统中的作用机理进行研究。结果表明:(1) NaOH、Na2CO3和水玻璃均能降低水的表面张力。其中水玻璃降低水的表面张力效力最好,当水玻璃(M=1.5)浓度按Na2O计为8%时,表面张力为39.9mN/m,降低了33 mN/m。阴离子表面活性剂萘系减水剂、氨基磺酸盐减水剂和聚羧酸盐减水剂降低水的表面张力幅度较小;阳离子表面活性剂十二烷基三甲基氯化铵、双癸基二甲基氯化铵和非离子表面活性剂十二烷基聚氧乙烯醚能显著降低水的表面张力。其中双癸基二甲基氯化铵降低水的表面张力效力最好,当浓度为50g/L时,表面张力为32.5 mN/m,降低了35.3 mN/m。(2)表面活性剂和碱对水表面张力的协同作用较复杂。阳离子表面活性剂能降低NaOH溶液的表面张力;表面活性剂在水玻璃溶液中对降低表面张力的作用甚微。(3)阴离子表面活性剂萘系减水剂和非离子表面活性剂十二烷基聚氧乙烯醚的吸附量较小,阴离子表面活性剂氨基磺酸盐减水剂和聚羧酸盐减水剂的吸附量最小,阳离子表面活性剂十二烷基三甲基氯化铵的吸附量最大,饱和吸附量为12.8 mg/g。(4)碱对表面活性剂在矿渣表面吸附的影响较复杂。加入碱后阴离子表面活性剂在矿渣颗粒表面的吸附量减小,阳离子表面活性剂在矿渣颗粒表面的吸附量增大,非离子表面活性剂的吸附量变化较小。更多还原

【Abstract】 Alkali-activated slag cement is a type of binding material using basic compound of alkali metal to activate slag(aluminosilicate), and Alkali-activated slag concrete based on which has many excellent performance, such as high strength, rapid hardening, low heat of hydration, good durability and so on. Many research achievement have been acquired mainly on the studies of activator, durability and setting time of alkali-activated slag cement and concrete. The researches and applications have be based on bad workability alkali-activated slag concrete until now. It is a mostly problem to embarrass application of alkali-activated slag cement and concrete that is big viscosity and bad workability of the new mixture with conventionality water-cement ratio. Adulterating surfactant is an important techno-means to solve the problem. Up to now, no systematic study has been done on effect mechanism of surfactant on alkali-activated slag cement and concrete. The study is an important theory foundation of researching plasticizers on alkali-activated slag cement and concrete, and has far-reaching significance to accelerate application of alkali-activated slag cement and concrete.By surface tension test, adsorbed amount test,ζpotential test and fluidity test for cement paste, the paper discusses the effect of variety surfactant and activator on surface tension, adsorbed amount,ζpotential and fluidity. Based on these, the effect mechanism of surfactant on alkali-activated slag cement and concrete has been studied. The research results can be concluded as following: (1) NaOH , Na2CO3 and Na2O·nSiO2 all debase the surface tension of water. Of which, water-glass has the best efficacity. When the modulus of water-glass is 1.5 and dosage of water-glass by Na2O is 8%, the surface tension is 39.9mN/m and reduces 33 mN/m. Naphthalene plasticizer, sulphamate plasticizer and polycarboxylate plasticizer reduce the surface tension of water less, [CH3(CH2)11N(CH3)3]Cl,[CH3(CH2)9]2N(CH3)2Cl and CH3(CH2)11(C2H4O)nH can reduce the surface tension of water better. Of which, [CH3(CH2)9]2N(CH3)2Cl has the best efficacity. When the concentration of [CH3(CH2)9]2N(CH3)2Cl is 50g/L, the surface tension is 32.5 mN/m and reduces 35.3 mN/m.(2) The effect of surfactant and alkali together on the the surface tension of water is complex. The cationic surfactants can debase the surface tension of NaOH solution.更多还原