粉煤灰PRC材料的制备

PRC（Pore Reduced Cement)是一种高性能水泥材料，它在工艺、性能、用途等方面有许多特有的优点，本文利用粉煤灰作为材料的组成部分，测试其力学性能.研究表明粉煤灰的最佳掺量为30％，粉煤灰PRC材料的微观结构显示，粉煤灰在PRC材料体系中主要是微集料作用。     

高性能高掺量粉煤灰蒸压砖的研究和应用

利用粉煤灰可以制造各种建筑材料.目前,已有的产品总体上可以分为四类:一是粉煤灰混凝土和粉煤灰砂浆;二是粉煤灰墙体材料;三是粉煤灰屋面材料;四是粉煤灰功能材料.由于粉煤灰所具有的独特的物理、化学性能,使粉煤灰建筑材料有着其他相关材料无法比拟的优势.例如,掺有粉煤灰的优质混凝土,其耐久性大大优于普通混凝土,在大体积混凝土建筑中,粉煤灰是浇注料中的不可缺少的组分.至于粉煤灰墙体材料更是改革开放以来尤其是近几年来国家大力倡导的新型墙体材料.高掺量粉煤灰蒸压砖是指以粉煤灰为主要原料(粉煤灰重量比掺量≥60%),掺加适量激发材料和骨料,经坯料制备、压制成型、高压蒸汽养护而成的新型墙体材料.按其外形可以分为实心标砖:规格:240×115×53mm、盲孔砖及空心砖(孔洞率≥25%)等.     

PRC低水胶比体系硅酸盐水泥水化特性与力学性能研究

本文研究了PRC（Pore Reduced Cement)材料的成型压力和养护龄期对水泥强度发展的影响和成型工艺与材料力学性能之间的联系，探讨了在PRC低水胶比体系中水泥的水化程度随龄期变化的规律和水泥水化产物微观形貌特点以及优化成型工艺来提高材料性能。     

英国粉煤灰在灌浆材料中的应用

本文介绍粉煤灰的一种新用途,即在灌浆材料中应用粉煤灰。文中除了介绍粉煤灰用于灌浆材料的种类和在灌浆材料中应用粉煤灰的优点外,还介绍粉煤灰水泥灌浆材料的生产、质量控制和该种材料的性能、配合比以及施工工艺。     

粉煤灰在建筑材料中的应用

粉煤灰作为一种电厂排放的大宗固体废弃物,具有特殊的化学活性,其综合利用是近年来研究的热点。本文结合粉煤灰的性质特点,综述了粉煤灰在高活性粉煤灰水泥混合材料、绿色高性能高掺量粉煤灰混凝土、高掺量粉煤灰烧结砖、衬砌材料、生产轻集料和空心砌块等领域,生产粉煤灰水泥、粉煤灰制砖、粉煤灰微晶玻璃等方面的应用,并在此基础上对加强粉煤灰在建筑中的应用提出了几点建议,同时对粉煤灰应用前景作了分析与展望,以提高经济效益和环境社会效益。使用粉煤灰作建筑材料不仅能节约能源与材料、降低生产成本和工程造价,而且生产出的材料的性能和各项指标与常规建筑材料相比有过之而无不及。     

粉煤灰在建筑业中的综合利用技术

3．粉煤灰在墙体材料中的应用以粉煤灰制作墙体材料是我国在粉煤灰综合利用方面最早开展的试验研究工作之一。在对粉煤灰基本性能和基础理论大量试验研究的同时,于60年代初开始研制以粉煤灰为主要原料的硅酸盐混凝土及其制品一粉煤灰硅酸盐砌块、外墙板及粉煤灰加气混凝土板。块等。这类墙体材料在70年代应用较多,80年代以后则主要发展粉煤灰混凝土小型空心砌块。3．1粉煤灰硅酸盐砌块粉煤灰硅酸盐砌块是以粉煤灰为主要原料,以石灰为激发剂,以石膏为增强剂,以煤渣、陶粒等为集料,按一定比例加水搅拌、振动成型、再经蒸气养护而成的一…     

粉煤灰填筑路基施工工艺的技术应用

在当前路基填筑的过程中,粉煤灰是常用的一种填筑材料。文章结合作者实际,分别总粉煤灰施工前的准备、施工场地清理、材料摊铺、材料压实等几方面内容,分析了粉煤灰在路基填筑工程中的应用,以供参考。     

粉煤灰助磨激发材料的应用研究

非等级低活性粉煤灰不能直接应用于水泥混凝土中,该文通过大量试验研究,将几种粉煤灰复合助磨激发材料与非等级低活性粉煤灰共同粉磨。研究表明:A、B、C三种粉煤灰助磨激发材料均能使粉煤灰需水量比减小,活性指数提高,其他指标均符合Ⅰ级粉煤灰技术规范标准要求。考虑粉煤灰活性激发效果与经济效益等因素,选用B型粉煤灰助磨激发材料作为该电厂久置粉煤灰的激发材料,用该材料磨制的粉煤灰需水量比小,活性指数较高,可以大量应用于水泥混凝中,该项研究成果解决久置粉煤灰的应用问题。     

配筋式管桩(PRC管桩)在基坑工程中的应用

目前配筋式管桩(PRC管桩)在基坑中的推广应用较少,本文针对某基坑的PRC管桩变形计算和观测数据进行详细分析,认为PRC管桩的支护效果好于预期,但是受降水影响,周边建筑存在一定沉降量。总的来说,PRC管桩有着广阔的前景,可为类似工程借鉴。     

挤密桩复合地基中粉煤灰的应用

多年来,粉煤灰虽然在建筑、筑路、农业等方面开展综合利用,但发展是不平衡的.在建筑工程中除广泛应用于蒸压粉煤灰砖、烧结粉煤灰砖、粉煤灰加气混凝土块、粉煤灰水泥、粉煤灰砂浆、粉煤灰垫层、粉煤灰填方材料等,在挤密桩复合地基中也有较多应用,虽然粉煤灰的掺加量不大,但挤密桩在处理软弱地基中量大面广,相对来讲,粉煤灰的应用也有相当的数量.     

Physical and mechanical properties of municipal solid waste incineration residues with cement and coal fly ash using X-ray Computed Tomography scanners

A significant volume of Municipal Solid Waste incineration bottom ash and fly ash (i.e., incineration residues) are commonly disposed as landfill. Meanwhile, reclamation of landfill sites to create a new land space after their closure becomes an important goal in the current fewer and fewer land availability scenario in many narrow countries. The objective of this study is to reclaim incineration residue materials in the landfill site by using cement and coal fly ash as stabilizers aiming at performing quality check as new developed materials before future construction. Indeed, physical and mechanical properties of these new materials should be initially examined at the micro scale, which is the primary fundamental for construction at larger scale. This research examines quantitative influences of using the combination of cement and coal fly ash at different ratio on the internal structure and ability of strength enhancement of incineration residues when suffering from loading. Couple of industrial and micro-focus X-ray computed tomography (CT) scanners combined with an image analysis technique were utilized to characterize and visualize the behavior and internal structure of the incineration residues-cement-coal fly ash mixture under the series of unconfined compression test and curing period effect. Nine types of cement solidified incineration residues in term of different curing period (i.e., 7, 14, 28 days) and coal fly ash addition content (i.e., 0%, 9%, 18%) were scanned before and after unconfined compression tests. It was shown that incineration residues solidified by cement and coal fly ash showed an increase in compression strength and deformation modulus with curing time and coal fly ash content. Three-dimension computed tomography images observation and analysis confirmed that solidified incineration residues including incineration bottom and fly ash as well as cement and coal fly ash have the deliquescent materials. Then, it was studied that stabilized parts play a more important role than spatial void distribution in increment or reduction of compression strength.     

Self-compacting concrete with different levels of pulverized fuel ash

This research investigated self-compacting concrete (SCC) with levels of up to 80% cement replacement by fly ash in mixes adjusted to give constant fresh concrete properties. The hardened concrete and the relationships between hardened properties were then studied.The results show that SCC with up 80% cement replaced by fly ash is possible. To keep the filling ability constant, replacement of cement with fly ash would require an increase in water/powder (W/P) ratio and a reduction in superplasticiser dosage. They also show fly ash have negative effects on passing ability, consistence retention and hardened concrete properties such as strength. The comparison between SCC and normally vibrated concrete (NVC) shows that their material properties of are similar. The successful completion of this project can lead to the use of higher volume fly ash in SCC.     

利用油母页岩生产高标号水泥实验研究

本文以油母页岩为原料,结合抚顺大火房水泥有限公司现有生产工艺条件,改进生料配料系统,研究用油母页岩配制的生料煅烧方法生产出高标号水泥,同时利用粉煤灰为活性掺合料。粉煤灰二次资源得到了利用,即降低了水泥成本,也减少了粉煤灰的污染,又改善了环境,发展了循环经济,实现了可持续发展。     

湿排粉煤灰固化强度试验研究

通过对海水湿排粉煤灰、水泥固化粉煤灰进行室内无侧限抗压强度试验和三轴压缩试验,以及对海水湿排固化粉煤灰材料强度形成机理分析,得到了水泥固化海水湿排粉煤灰基本力学性质及指标．通过设计试验对不同龄期、水泥固化剂掺量及养护条件影响因素进行分析,得到水泥固化海水湿排粉煤灰在不同条件下的强度变化规律．试验结果表明,水泥固化海水湿排粉煤灰具有良好的稳定性和耐久性,拌和固化混合料强度随龄期稳定增长,随水泥掺量增加强度提高．该试验研究对挡土结构、路基加固及地基处理等工程应用有重要的理论与实践研究价值．     

原状粉煤灰与钢纤维复合用于机场道面混凝土

将原状粉煤灰掺入机场道面用钢纤维混凝土中,研究了以原状粉煤灰等量取代、超量取代水泥及在水泥用量不变的条件下仅将其作为微细集料使用时对钢纤维混凝土性能的影响,探讨原状粉煤灰在机场道面用钢纤维混凝土中应用的可能性,以提高机场道面用钢纤维混凝土的力学性能,改善其内部结构,并降低一次性投资,为推广应用该项技术提供依据.     

磷酸镁水泥中的粉煤灰效应研究

采用宏观性能与微观分析相结合的方法研究了粉煤灰在磷酸镁水泥体系中的多种效应,包括活性效应、微集料效应和形貌效应,并通过试验设计与分析,确认粉煤灰在磷酸镁水泥体系中还存在着吸附效应.     

矿物掺和料对玄武岩纤维水泥砂浆强度发展的影响

研究了粉煤灰和硅灰对玄武岩纤维增强水泥基材料强度发展规律的影响,分析了粉煤灰和硅灰复掺对水泥砂浆中玄武岩纤维耐腐蚀性的影响.结果表明：玄武岩纤维对水泥基材料的早期抗折强度具有增强作用,后期增强效果下降,甚至会降低基体强度;粉煤灰和硅灰可显著延长玄武岩纤维对水泥砂浆抗折强度增强效果的时效.XRD图谱和显微结构分析表明,粉煤灰和硅灰复掺后降低了水泥基体中Ca(OH)2晶体的含量和玄武岩纤维的腐蚀程度,改善了玄武岩纤维和水泥基体之间的界面性质.     

微珠粉煤灰在超高性能混凝土中的应用

通过微珠粉煤灰与普通粉煤灰物化性能比较,以及对掺加微珠粉煤灰混凝土的出机状态、拌合物工作性及硬化后耐久性进行检测,结果证明:微珠粉煤灰粒径小、活性高、减水性好、填充性佳且需水量很小,是超高性能混凝土中的重要组分,可显著提高混凝土的流动性,大大降低超高性能混凝土的粘度,减小混凝土泵送阻力,适宜在超高层高强高性能混凝土中推广应用。     

A study on the hydration rate of natural zeolite blended cement pastes

Natural zeolite is a type of mineralogical material containing large quantities of reactive SiO₂ and Al₂O_3. It is widely used in the cement industry in China as a cement blending material. Like other pozzolanic materials such as silica fume and fly ash, zeolite contributes to concrete strength mainly through the pozzolanic reaction with Ca(OH)₂, Thus, the pozzolanic reactivity of this type of material in comparison with other pozzolans is of much interest. This paper presents experimental results on the compressive strength, degree of pozzolanic reaction, and porosity of zeolite modified cement pastes. These results are compared with those obtained from similar blended cement pastes prepared with silica fume and fly ash replacements. Based on the experimental results, it can be concluded that natural zeolite is a pozzolanic material, with a reactivity between that of silica fume and fly ash. Generally, in blended cement pastes with a lower water-to-cementitious materials ratio, the natural zeolite contributes more to the strength of the pastes. But in the pastes with a higher water to cementitious ratio and a lower cement replacement level it undergoes a higher degree of reaction.     

脱硫粉煤灰制备复合水泥性能研究

通过试验研究掌握了大连市几家电厂排放的粉煤灰特性,探讨了脱硫粉煤灰生产复合水泥的可行性,试验得出用脱硫粉煤灰制备的复合水泥其主要技术性质,从而讨论粉煤灰混合材料对水泥物理力学性能的影响,确定配制水泥中粉煤灰混合材料的掺入量。