摘要
二十世纪末,干混砂浆作为一种新型建筑材料出现在我国建筑业市场。相对于传统现场拌制砂浆而言,干混砂浆有更加精确的配比、更加合适的外加剂,具有优良的工作性能和良好的质量保证。干混砂浆能利用大量的粉煤灰、脱硫石膏、矿渣等工业废料,减轻环境压力,为施工现场节约材料堆放场地,提高施工效率。我国通用硅酸盐水泥的最低强度等级为32.5MPa,而干混砂浆(如抹灰砂浆的强度等级为M5、M10、M15和M20)的强度等级偏低。目前我国市场上没有专用砂浆水泥,建筑施工现场用通用硅酸盐水泥(即纯水泥)直接配制砂浆,这导致水泥的浪费和砂浆质量问题的频频发生;干混砂浆企业采用通用硅酸盐水泥配制砂浆、同时大掺量粉煤灰调节强度等级。如何发挥干混砂浆中粉煤灰的胶凝作用,进一步降低干混砂浆中水泥掺量,从而进一步降低成本和改善砂浆的质量,这是砂浆企业急需解决的问题。
本论文以郑州电厂原状粉煤灰、郑州电厂磨细粉煤灰、洛阳低钙粉煤灰和郑州电厂脱硫石膏与水泥为主要原材料,采用固定变量的研究方法,对“低水泥大掺量粉煤灰和烟气脱硫石膏”的胶凝性进行了系统研究。研究结果表明:郑州电厂原状粉煤灰的性能指标达不到Ⅲ级灰指标,但经过磨细处理,达到Ⅱ级灰的指标,磨细灰可以完全代替Ⅱ级洛阳低钙粉煤灰配制干混抹灰砂浆,并且配制的砂浆各项性能指标更好;“低水泥大掺量粉煤灰和烟气脱硫石膏”的胶砂强度随水泥掺量增加而提高,与烟气脱硫石膏的掺量有一个较优比例,例如当水泥掺量20%和30%、烟气脱硫石膏30%时,“低水泥大掺量磨细粉煤灰和烟气脱硫石膏”的胶砂强度分别为19.3MPa和24.6MPa,达到我国砌筑水泥12.5和22.5强度等级;“低水泥大掺量粉煤灰和烟气脱硫石膏”的胶凝材料体积收缩率随水泥掺量增加而加大、随烟气脱硫石膏的掺量增加而减小,掺磨细粉煤灰的干混砂浆专用胶凝材料体积收缩率比原状粉煤灰略小。
本文采用扫描电镜(SEM)和X射线衍射(XRD)分析表明:与原状粉煤灰相比,磨细粉煤灰由于表面经过机械活化作用,在水泥和脱硫石膏的双重激发作用下,磨细粉煤灰水化硬化速度更快、微观结构更致密、硬化体强度更高。
The end of the twentieth century, dry-mixed mortar was introduced in our country's construction market as a newly building. This mortar has more accurate proportion, more proper additives, it has excellent workability and better quality assurance after experimental demonstration, it can also use a large number of fly ash, gypsum, slag and other industrial waste and relieve environmental pressure, save material stacking sites for the construction site, improve construction efficiency etc. Minimum strength grade of our common Portland cement is32.5MPa, and dry mixed mortar (such as grade of plastering mortar strength is M5, M10, M15and M20) Strength is relatively low. At present there is no special mortar cement in our market, general Portland cement (i.e. pure cement mortar) formulated mortar directly in the construction, which led to the waste of cement and mortar quality problems occurred frequently, Dry mixed mortar enterprises use common Portland cement mixing of mortar, and mixed with large amount of fly ash by modulating the intensity grade. How to play the cementitious role of fly ash in dry mixed mortar, further reduce the cement content of dry mixed mortar to reduce the cost and improve the quality of mortar, which is in need of the problem of solving by mortar enterprises.
The original fly ash and ground fly ash of Zhengzhou power plant, Luoyang low calcium fly ash, desulfurization gypsum in Zhengzhou power plant as main raw materials were taken in this paper. The study method of fixed variables was used, the cementitious material of " low cement content with a large volume of fly ash and flue gas desulfurization gypsum " was studied systematically in this paper. The results showed that:Zhengzhou power plant fly ash performance indicators are not up to class Ⅲ ash index, but after ground treatment, which achieves class Ⅱ ash index. Ground ash can completely replace the grade Ⅱ Luoyang low calcium fly ash in dry mixed plastering mortar, and the performances of producing mortar are better; The compressive strengths of the mortar produced by " low cement content with a large volume of fly ash and flue gas desulfurization gypsum " increase with the cement content increase, and there is an optimal value of compressive strengths with the increase of the gas desulfurization gypsum content. For example, when the cement content is of20%and30%and flue gas desulfurization gypsum is of30%in " low cement mixed with large amount of ground fly ash and flue gas desulfurization gypsum ", the compressive strengths of producing mortars are19.3MPa and24.6MPa, this value reaches our country masonry cement strength grade of12.5and22.5; The volume shrinkage of the mortar produced by " low cement content with a ground of fly ash and flue gas desulfurization gypsum" increase with cement content increase and reduce with flue gas desulfurization gypsum content increase, and the volume shrinkage of the mortar with pulverized fly ash is smaller than that of the mortar with original fly ash.
The scanning electron microscope (SEM) and Ⅹ ray diffraction (XRD) analysis were used in this paper, the results showed that compared with original fly ash, the ground fly-ash has faster speed of hydration hardening and more compact microstructure and higher strength of hardened paste because of the surface of mechanical activation and cement and gypsum double excitation.
引文
[1]丁健一,王新民,武美燕.我国预拌砂浆行业改革与发展行业研究报告[M].商品砂浆研究进展.北京:机械工业出版社,2007.10,3-5
[2]汪友双.预拌砂浆对节能减排的贡献不容忽视[J].预拌砂浆.2011.4,47-48
[3]刘慧明.推广预拌砂浆促进建筑节能[J].散装水泥.2010.6,44-45
[4]叶蓓红,谈晓青.我国脱硫石膏与脱硫建筑石膏质量问题及成因分析[J].粉煤灰.2009.6,38-39
[5]王培铭,张国防.干混砂浆的研究进展[M].商品砂浆的研究与应用.北京:机械工业出版社,2006.1,3-5
[6]郑厚斌.2007年我国预拌砂浆产业发展状况及未来发展趋势分析[C].2008年第三届国际建筑干混砂浆生产应用技术研讨会论文集.北京,2008.4,1-3
[7]Johann Plank. Effects of the chemical structure on the properties of polycarboxylate-type super plasticizer. Cement and Concrete Research, February,2000.30(2):P 197-207.
[8]M.Guld. Produktion und Verarbeitung von werktrockenmorteln. ZKG, 52,1999,628-631
[9]Chai Jaturapitakkul. Use of ground fly ash as a replacement of condensed silica fume in producing high-strength concrete [J]. C.C.R,2003, (4):549-555.
[10]王子明.商品砂浆用化学外加剂[M].商品砂浆的研究与应用.北京:机械工业出版社,2006.1,88-95
[11]林瑞,张鸿毓,张环宇等.系列商品砂浆专用外加剂的研制与应用[M].商品砂浆的研究与应用.北京:机械工业出版社,2006.1,105-111
[12]强卫,曹春,黄聪华等.KJ-5RL高效减水剂在商品砂浆中的应用[M].商品砂浆的研究与应用.北京:机械工业出版社,2006.1,133-135
[13]陈益兰,李毅,尤卫玲.商品砂浆中保水增稠材料的研究[M].商品砂浆的研究与应用.北京:机械工业出版社,2006.1,256-260
[14]段鹏选,宋作宝,苗元超.低成本保水增稠剂在普通干混砂浆工业化生产中的应用[C].2008年第三届国际建筑干混砂浆生产应用技术研讨会论文集.北京,2008.4,83-98
[15]陈晓业,王培明,张国防.憎水剂对水泥力学胶砂性能和吸水性的影响[M].商品砂浆的研究进展.北京:机械工业出版社,2007.10,110-116
[16]蹇守卫,马保国,马玲等.高效释水材料在干混砂浆中的作用与机理[M].商品砂浆的研究进展.北京:机械工业出版社,2007.10,117-122
[17]马保国,张风臣,马玲等.低成本高效抗裂砂浆外加剂的研究[M].商品砂浆的研究进展.北京:机械工业出版社,2007.10,133-138
[18]张承志,王爱勤,董芹芹.乳胶粉对硬化水泥石干缩变形和失水过程的影响[M].商品砂浆的研究进展.北京:机械工业出版社,2007.10,51-56
[19]钟志锦,庄绪生,李国忠等.聚丙烯纤维聚合物砂浆的基本性能研究[M].商品砂浆的研究进展.北京:机械工业出版社,2007.10,144-152
[20]庄梓豪,于其俊,韦江雄.矿物掺合料对干混砂浆性能的影响及配比的优化[M].商品砂 浆的研究进展.北京:机械工业出版社,2007.10,179-189
[21]潘钢华,夏艺,王然良.凹凸棒土对干混砂浆性能影响机理的研究[M].商品砂浆的研究进展.北京:机械工业出版社,2007.10,165-170
[22]毛永琳,刘建忠,刘加平.聚合物改性水泥基干混防水砂浆的研究[M].商品砂浆的研究进展.北京:机械工业出版社,2007.10,220-224
[23]约翰·舒尔茨.可再分散乳胶粉在砂浆中的主要作用[M].商品砂浆的研究进展.北京:机械工业出版社,2007.10,309-320
[24]高英力,陈瑜,王迪等.脱硫石膏—粉煤灰活性掺合料设计及水化特性[J].四川大学学报,2010.3(2)225-228.
[25]陈金平.化学激发粉煤灰-水泥体系的膨胀和抗侵蚀性研究[J].粉煤灰综合利用,2010.1,37-39
[26]栾晓风,潘志华,王冬冬.粉煤灰水泥体系中粉煤灰活性的化学激发[J].硅酸盐通报,2010.8,4(29),757-761
[27]刘宝举,梁慧,杨元霞.复合激发剂对粉煤灰的活性激发作用[J].铁道科学与工程学报,2008.12,5(6),6-9
[28]乔宏霞,王永亮,余红发.矿物掺合料细度对水泥胶砂力学性能的火出灰效应[J].粉煤灰综合利用,2010.2,14-19
[29]杨久俊,张茂亮.粉煤灰活性激发影响因素研究[J].粉煤灰综合利用,2007.5,15-17
[30]位建强,刘巧玲,曹明莉.脱硫石膏-粉煤灰-矿粉复合胶结材改性研究[J].新型建筑材料,2010.4,9-12
[31]WALLAH S E, RANGAN B V. Low-calcium fl y ash-based geo-polymer concrete: long-term properties [R]. Research Report GC 2, Faculty of Engineering, Cumin University of Technology, Perth, Australia,2006.
[32]郑权.当前预拌砂浆面临的发展机遇与挑战[C].2010年第四届国际建筑干混砂浆生产应用技术研讨会论文集.北京,2010,1-3
[33]怀思.专家谈我国干混砂浆发展现状及发展趋势[J].商品砂浆,2006.8,21-23
[34]武美燕.我国预拌砂浆纵谈[J].商品砂浆散装水泥,2008(3),23-26
[35]孔安,高全胜.我国预拌砂浆的发展趋势[C].2010第四届国际建筑干混砂浆生产应用技术研讨会论文集,2010,30-36
[36]赵越群,樊钧,陈宁.预拌砂浆质量通病原因分析及对策[C].2010第四届国际建筑干混砂浆生产应用技术研讨会论文集,2010,37-41
[37]付文瑞.干混砂浆市场现状及发展趋势[J].新型建材与施工技术,2010.2,51-52
[38]张斌.从使用环节入手加强预拌砂浆推广力度[C].2010第四届国际建筑干混砂浆生产应用技术研讨会论文集,2010,53-59
[39]王培铭,张国防.干混砂浆的应用研究进展及发展对策[C].2010第四届国际建筑干混砂浆生产应用技术研讨会论文集,2010,12-15
[40]张裕民,董猛,孔岩涛.试论我国建筑砂浆发展的儿个问题[C].2010第四届国际建筑干混砂浆生产应用技术研讨会论文集,2010,26-29
[41]ZHUTOVSKY S, KOVLER K, BENTUR A. Efficiency of lightweight aggregates for internal curing of high strength concrete for eliminate autogenously shrinkage[J].Materials and Structures,2002 (35):97-101.
[42]马保国,李相国,何真.碱对水泥基材料收缩性能的影响[J].武汉理工大学学报.2005.1,27(1):33-34
[43]LURA P, BENTZ D P, LANGE D A, et al. Measurement of water transport from saturated pumice aggregates to hardening cement paste[J].Materials and Structures,2006 (39) 861-868.
[44]LURA P, JENSEN, IGARASHI S. Experimental observation of internal water curing of concrete[J].Materials and Structures,2007 (40):211-220.
[45]周万良,詹炳根,龙靖华.粉煤灰-石灰-二水石膏胶凝材料的体积稳定性及水化产物的性能[J].粉煤灰.2010.1;8-10
[46]FERNANDEZ-JIMENEZ A, PALOMO J, SOBRADOS I, et al. The role played by reactive alumina content in the alkaline activation of fl y ashes[J]. Micro or Mater.2006.91: 111-119.
[47]SUN Peijiang. Fly ash based organic polymeric building material [D].Wayne State University, Detroit, Michigan,2005.
[48]BUCHWALD A, DOMBROWSKI K, WEIL M. The influence of calcium content on the performance of geo-polymeric binder especially the resistance against acids [A]//4th International Conference on Geo-polymers [C], St Quentin, France.
[49]栾晓风,潘志华,王冬冬.粉煤灰水泥体系中粉煤灰活性的化学激发[J].硅酸盐通报,2010.8,29(4),757-761
[50]陶文宏,刘宗明,张明星.脱硫石膏-石灰-粉煤灰体系胶凝性及水化机理[J].济南大学学报,2010.7,23(3),233-237
[51]王磊,何真,张博等.粉煤灰-水泥水化的核磁共振定量分析[J].硅酸盐学报,2010,38(11)
[52]张燕迟、钱文勋、蔡跃波等.激发剂对高掺量粉煤灰早期水化的作用机理[J].武汉理工:大学学报,2010.4,32(7),44-47
[53]徐子芳,张明旭,许海仙.石灰-石膏-粉煤灰水泥浆体的水化机理研究[J].环境工程学报.2009.10,10(3),1879-1884