粉煤灰在砌筑砂浆中的应用（摘要）

粉煤灰在砌筑砂浆中的应用（摘要）沈振岳，殷济波（中建七局二公司）在砌筑砂浆中掺入原状粉煤灰，不仅可以收到节约水泥，取代部份石灰膏，降低成本的效果，而且使砂浆的和易性也得到改善，我们采用芜湖发电厂的原状粉煤灰，进行了粉煤灰水泥砂浆和粉煤灰石灰混合砂浆的...     

高强高性能大掺量粉煤灰砂浆试验研究

在论述我国粉煤灰开发利用的基础上，总结了大掺量粉煤灰建筑砂浆，高强高性能粉煤灰砌筑砂浆试验研究成果。     

原状粉煤灰代砂砌筑砂浆的研究

建筑工程需要大量砌筑砂浆,用原状粉煤灰代砂配制砌筑砂浆能改善砌筑砂浆性能、降低砂浆造价。 1、原材料粉煤灰采用江阴市周庄电厂干排灰。水泥用无锡市水泥厂和宜兴市十里牌水泥厂生产的425~#普通硅酸盐水泥。石灰膏为市场上出售的石灰膏,砂为一般中砂。 2、粉煤灰代砂砌筑砂浆性能对比试验试验分两次进行,第一次采用无锡市水泥厂水泥,第二次采用宜兴市十里牌水泥厂水泥,配制比较有代表性的Mu5.0级混合砌筑砂浆进行性能对比。试验结果列于表1。砂浆试块在标准养护室内空气养护,相对湿度80～90％。     

粉煤灰砌筑砂浆和粉煤灰抹灰砂浆应用实例

我国研究应用粉煤灰砌筑砂浆和粉煤灰抹灰砂浆已有数十年历史。在砌筑砂浆中适量掺入粉煤灰,对于改善砂浆性能、保证工程质量、节约水泥、降低成本及保护环境、节约土地等均有明显效益。而绝大多数建筑工程都要抹灰,在抹灰砂浆中掺用粉煤灰,是一项技术成熟效益显著的用...     

粉煤灰砂浆在砌筑工程的试验研究

粉煤灰砌筑砂浆是由粉煤灰、325~#矿渣水泥、废型砂、石粉、石屑等原料配制而成,是一种具有水泥混合砂浆使用性能的砌筑砂浆。徐州市对生产粉煤灰砂浆,经过中试、批量生产,现已进入建筑工程应用。本文仅就粉煤灰砌筑砂浆的砖砌体强度及砂浆的耐水性、抗冻性在建筑工程上应用试验作一探讨。 1.砖砌体试验 1.1 试验方法 1.1.1 试件:用配好的干拌50~#(M5)、100~#(M10)粉煤灰砂浆,在砌筑现场加水拌合,试件全部采用整砖砌筑并按《GBJ3—73》附录四要求制作。     

混凝土空心砌块用大掺量粉煤灰砌筑砂浆的研制

开发了一种非引气型砂浆增塑剂,它可用于普通水泥砂浆或水泥石灰混合砂浆,也可用于粉煤灰掺量为50%的水泥砂浆中.开发的混凝土空心砌块砌筑砂浆可用于多孔砖等块体墙材的砌筑.     

复合矿物掺和料对薄灰缝砌筑砂浆强度影响的研究

在宏观层面上进行了关于粉煤灰、矿渣两种矿物掺和料对薄灰缝砌筑砂浆不同龄期(7,28 d)抗折、抗压强度影响规律的研究。其中,研究变量包括两种掺和料单、双掺时等质量替代水泥的掺量及双掺时两者之间相互比例、各自细度等因素。结果表明,单掺时仅10%掺量的粉煤灰能略提高砂浆强度,约提高5%;相同粉煤灰掺量下,粉煤灰研磨细度对提升砂浆强度有促进作用。砂浆各龄期强度随矿渣单掺量增加而持续下降。当粉煤灰、矿渣混掺时,两者特定比例(15%研磨20 min粉煤灰+15%研磨40 min矿渣)组合能较大幅度提升薄灰缝砌筑砂浆抗压强度,最高可提高19%。在微观层面上从各种颗粒的微观形态、尺寸及级配等因素角度出发进行了解释并对水泥-粉煤灰-矿渣三维胶凝体系进行了分析。     

粉煤灰对混凝土小型空心砌块专用砌筑砂浆性能影响研究

砌筑砂浆是影响混凝土小型空心砌块房屋产生裂缝的重要原因,而粉煤灰是影响砂浆性能的很重要的一个因素.试验研究了粉煤灰对混凝土小型空心砌块砌筑砂浆性能的影响,获得比较理想的灰砂比以进一步研制专用砌筑砂浆.     

煤气化渣玻化微珠制备保温砂浆

利用煤气化渣合成的玻化微珠(VM-CGS)作为保温骨料制备保温砂浆,研究了VM-CGS粒径和掺量、粉煤灰替代水泥量以及憎水剂添加量对保温砂浆性能的影响.实验结果表明,VM-CGS是一种内部呈蜂窝状骨架结构,以闭孔为主的轻质保温骨料.由3～5mm粒径的VM-CGS制备的保温砂浆性能最优.VM-CGS掺量增加虽然可以降低样品导热系数,但样品的其他性能会随之减弱.粉煤灰替代10％(质量分数)的水泥可以提高保温砂浆整体性能,憎水剂掺量达到水泥质量0.8％以后才能实现有效憎水.利用VM-CGS可制备出满足GB/T 20473-2006《建筑保温砂浆》的Ⅰ型保温砂浆.     

高掺量粉煤灰试制砌筑水泥的试制研究

对于用粉煤灰试制和生产砌筑水泥,一些同行们相继作了研究,我们所进行的用粉煤灰试制砌筑水泥的研究,是期望尽可能多用粉煤灰,试制出符合《GB3183—82》标准规定的砌筑水泥,为粉煤灰的充分利用开辟途径。试验结果表明,在所试制的125标号砌筑水泥中粉煤灰的掺入量达到75—80%,它可用于工业与民用建筑的砌筑砂浆和内外墙抹面砂浆。     

粉煤灰掺量对矿渣-水泥胶砂耐磨性和强度的影响

研究了粉煤灰掺量对矿渣-水泥胶砂28 d、45 d和350 d耐磨性和强度的影响.在矿渣-水泥胶砂中掺入10%的粉煤灰后胶砂28 d、45 d和350 d耐磨性可增大也可减小,但当粉煤灰掺量≥20%时,均降低,且随粉煤灰掺量继续增加,不断降低.在矿渣-水泥胶砂中掺入10%粉煤灰后胶砂28 d、45 d强度减小,且随粉煤灰掺量继续增加,不断减小.在矿渣-水泥胶砂中掺入粉煤灰后,胶砂350 d强度可增加也可降低,取决于粉煤灰掺量和矿渣取代水泥量.随掺粉煤灰的矿渣-水泥胶砂强度增大,胶砂磨损率总体趋势减小,但并不单调减小.     

基于粉煤灰掺量的砂浆塑性收缩开裂本构关系的研究

研究了粉煤灰掺量对于砂浆塑性收缩性能和塑性粘度的影响。试验表明,随着粉煤灰掺量的增加,砂浆抗裂指数增大,开裂所需时间增加,塑性粘度降低;建立了粉煤灰掺量与砂浆抗裂指数、开裂时间的本构关系,及掺加粉煤灰后砂浆塑性粘度与抗裂指数的本构关系。     

分选与磨细粉煤灰对水泥胶砂性能的影响

研究了分选与磨细粉煤灰的颗粒分布与形貌的差异及对水泥胶砂性能的影响。研究结果表明:当勃氏比表面积相近,磨细粉煤灰的中位粒径大于分选细粉煤灰,其圆珠状颗粒较少,表面较为粗糙。在相同水胶比的条件下,掺分选粗粉煤灰的水泥胶砂流动度及强度均低;分选粗粉煤灰磨细后,不仅减少了颗粒的粘连,增加了比表面积,而且提高了粉煤灰的反应活性和水泥胶砂流动度及强度,虽其水泥胶砂流动度仍小于掺分选细粉煤灰的水泥,3d水泥胶砂强度也略低,但其28d水泥胶砂强度略高于掺分选细粉煤灰的水泥;在相同水泥胶砂流动度的条件下,掺磨细粉煤灰配制的水泥胶砂3d强度低于掺分选细粉煤灰的水泥,但随着水化龄期的增长,其差距逐步缩小,至60d时可超过后者。     

砂浆中粉煤灰的最佳掺量

分别以砂浆抗压强度、粉煤灰单位强度因子为指标研究了砂浆体系中粉煤灰的最佳掺量范围.并结合实验探讨了充分水化条件下,水胶比、粉煤灰种类等因素对砂浆体系中粉煤灰最佳掺量的影响规律.结果表明:水胶比、粉煤灰种类对砂浆中粉煤灰的最佳掺量存在较大影响.在所调查的实验条件下,粉煤灰的最佳掺量范围为20%～30%(质量分数).砂浆抗压强度最高值和粉煤灰单位强度因子最大值处分别所对应的粉煤灰最佳掺量并不相同.     

Packing effect and pozzolanic reaction of fly ash in mortar

This research is to study the effect of particle size of fly ash on packing effect and pozzolanic reaction of mortar when 20% of fly ash is used to replace Portland cement type I. Both effects can be determined by using fly ash and insoluble material which have almost the same particle size to replace Portland cement type I. Normally, the compressive strength of fly ash mortar is contributed from hydration reaction, packing effect, and pozzolanic reaction. For mortar mixed with insoluble material, the compressive strength is due to hydration reaction and packing effect. Thus, compressive strength due to pozzolanic reaction can be determined from the difference in compressive strength between fly ash mortar and insoluble material mortar. The results show that the strength activity index of fly ash mortar depends on the median particle size of fly ash and curing ages of mortar samples. At early ages, the strength activity index of fly ash mortar due to packing effect is higher than that due to pozzolanic reaction. At the ages of 3 to 90 days, the difference in strength activity index due to packing effect of fly ashes with median particle size of 2.7 and 160 μm is almost constant about 22% of the strength of standard mortar (STD). The differences in strength activity index due to pozzolanic reaction of fly ashes with median particle size of 2.7 and 160 μm are 3%, 20%, and 27%, respectively, at the ages of 3, 28, and 90 days.     

矿物掺合料细度对水泥胶砂力学性能的火山灰效应

通过分析单掺矿粉、单掺不同磨细程度的粉煤灰及复掺粉煤灰和矿粉的胶砂早期强度的变化规律,得出粉煤灰的磨细程度及粉煤灰与矿粉的复掺比例会影响胶砂的早期强度。粉煤灰越细,越有利于提高胶砂早期强度,复合掺合料之间各成分的最佳配合比可以充分发挥各自的活性,从而提高胶砂早期力学性能。     

粉煤灰-矿渣微粉复合双掺对水泥砂浆抗酸雨侵蚀性能的影响

研究了粉煤灰、矿渣微粉复合双掺时对水泥砂浆的强度以及抗模拟酸雨侵蚀性能的影响。通过试验发现:随着粉煤灰、矿渣微粉总掺量的不断增加,砂浆强度逐渐下降;各不同配比的砂浆经pH值为4.0的模拟酸雨干湿交替循环腐蚀后的强度变化规律为先升高后下降;与纯水泥砂浆试件相比,如粉煤灰、矿渣微粉的掺入过高,则会降低试件的强度值,但是如以强度增长率来评价砂浆的抗酸雨侵蚀能力,则各不同比例的粉煤灰、矿渣微粉复合双掺等量取代水泥配制的砂浆的强度增长率均优于同等条件下纯水泥砂浆试件,即粉煤灰、矿渣微粉复合双掺对水泥砂浆试件在模拟酸雨条件下的强度发展有改善作用。     

Influence of fly ash fineness on strength, drying shrinkage and sulfate resistance of blended cement mortar

In this paper, the influence of fineness of fly ash on water demand and some of the properties of hardened mortar are examined. In addition to the original fly ash (OFA), five different fineness values of fly ash were obtained by sieving and by using an air separator. Two sieves, Nos. 200 and 325, were used to obtain two lots of graded fine fly ash. For the classification using air separator, the OFA was separated into fine, medium and coarse portions. The fly ash dosage of 40% by weight of binder was used throughout the experiment. From the tests, it was found that the compressive strength of mortar depended on the fineness of fly ash. The strength of mortar containing fine fly ash was better than that of OFA mortar at all ages with the very fine fly ash giving the highest strength. The use of all fly ashes resulted in significant improvement in drying shrinkage with the coarse fly ash showing the least improvement owing primarily to the high water to binder ratio (W/B) of the mix. Significant improvement of resistance to sulfate expansion was obtained for all fineness values except for the coarse fly ash where greater expansion was observed. The resistance to sulfuric acid attack was also improved with the incorporation of all fly ashes. In this case the coarse fly ash gave the best performance with the lowest rate of the weight loss owing probably to the better bonding of the coarse fly ash particles to the cement matrix and less hydration products. It is suggested that the fine fly ash is more reactive and its use resulted in a denser cement matrix and better mechanical properties of mortar.     

粉煤灰掺量对碱激发矿渣砂浆减缩特性研究

研究粉煤灰掺量对碱激发矿渣砂浆的凝结时间、抗压强度、化学收缩和自收缩的影响因素和影响规律.结果表明,加入粉煤灰不仅能有效改善碱激发矿渣砂浆凝结快,收缩变形大的问题,同时也能够解决碱激发粉煤灰砂浆在常温条件下早期强度低和强度发展缓慢等问题.配比不同掺量的粉煤灰,以寻求最佳的掺量,在保证碱激发矿渣砂浆强度的同时提高减缩效果.     

粉煤灰对UEA膨胀性能的影响

研究了不同掺灰量对UEA膨胀剂水泥砂浆和混凝土膨胀性能的影响。结果表明 ,原状灰对UEA膨胀剂的膨胀性能基本没有影响 ,而磨细灰则有较大的影响 ,掺灰量越大 ,影响越大。当磨细灰掺量超过 10 %时 ,UEA的膨胀性能受到削弱