Effect of shale addition on properties of sintered coal fly ash

Shale can be used as a substitute for clay in sintered fly ash, due to the similar physical and chemical property to clay. In this paper, these characteristics of sintered fly ash with or without shale (binder) were investigated by physical property, X-ray diffraction and scanning electron microscopy. The results show that shale addition ranging from 30% to 50% (in weight) can be beneficial for properties of sintered products at temperature ranging from 950 to 1050 °C. However, a higher amount of shale easily caused significant bloating at 1100 °C. Considering energy saving and best performance, the sintering mix for shale and fly ash (50% in weight respectively, the same as below) fired at 1000 °C for 2 h was an optimal option. XRD results of the sintering mix show that intensity of hercynite increases with the increasing temperature, but intensity of quartz decreases on sintering. SEM confirms that addition of shale can improve microstructure and sintering of fly ash.     

Effect of different fibers on the mechanical properties of concrete containing fly ash

The results of an experimental investigation to study the effects of replacement of cement (by weight) with three percentages of fly ash and effects of addition of steel and polypropylene fibers are presented. Current day knowledge of concrete technology focuses attention primarily on the use of different materials in the production of concrete, industrial wastes in particular. The use of fly ash in concrete today is an important subject and is growing in importance day by day. Using fly ash in concrete may both provide economical advantages and better properties in the production of concrete. Besides, concretes produced with three different replacement ratios of fly ash and three different types of steel and polypropylene fibers were compared to those without fibers used in concrete with FA. According to the results of the study, addition of fibers provide better performance for the concrete, while fly ash in the mixture may adjust the workability and strength losses caused by fibers, and improve strength gain.     

粉煤灰釉质波瓦的开发

粉煤灰釉质波瓦是以粉煤灰（或炉渣）为基料，加入功能性材料与胶结剂，采用多层复合央芯结构制成。其高光高强，装饰性、抗冻性、抗渗防水、耐老化性、保温隔热性、防火性及经济效益均优于水泥石棉瓦，而且不含石棉。它的开发成功对水泥石棉波瓦产品的换代及治理粉煤灰污染，都具有一定意义。     

利用粉煤灰制瓦试验研究

粉煤灰是煤粉炉烟气中收集的灰分 ,它是火力发电厂等燃煤粉炉工厂排出的废料。堆放这些粉煤灰 ,不仅需要占用土地 ,而且造成严重的环境污染。如粉煤灰排入江河湖海 ,则又污染水质 ,淤塞航道。粉煤灰颗粒小 ,利用它掺合制砖可以减少粉碎工序 ,而且烧结粉煤灰制品比普通粘土制品脱水快、干燥收缩小 ,大大缩短了干燥周期。同时烧成后制品容重轻 ,制品表面比较光滑。因此 ,用粉煤灰制砖 ,可以节约粘土 ,化害为利。粉煤灰为细粉状 ,呈灰黑色、灰色或灰白色。粉煤灰颗粒是一种具有巨大比表面积的多孔结构 ,主要为玻璃体。粉煤灰基本无塑性可言 ,单…     

低等级粉煤灰混凝土的力学性能研究

介绍了采用化学激发、水热激发与机械磨细相结合的高效复合活化技术对低等级粉煤灰进行活化处理,对不同掺入量的C30粉煤灰混凝土立方体试样进行了试验及力学性能分析,试验证明这种技术处理能够显著提高粉煤灰混凝土的早期强度和后期强度。     

蒸压粉煤灰砖基本力学性能研究

按照《砌墙砖试验方法》(GB/T2542-2003)对蒸压粉煤灰砖进行砖的含水率、抗压强度、抗折强度试验。确定蒸压粉煤灰砖的基本力学指标,为编制辽宁省地方标准《蒸压粉煤灰砖建筑技术规范》提供试验依据。结果表明,蒸压粉煤灰砖含水率为2.96%,抗压强度为11.46MPa,抗折强度为1.68MPa,在实际工程上可替代普通烧结砖使用。     

用粉煤灰生产码头用高强度混凝土路面砖的研究

本文介绍了一种大掺量粉煤灰和外加剂双掺法生产码头用高强度混凝土路面砖的实验数据、理论研究以及在生产中的应用,产品强度达到Cc50以上.提出一条适用于建材企业降低成本,提高质量的新途径.     

粉煤灰对高温后UHTCC试块抗折强度的影响

对控制不同粉煤灰含量的超高韧性水泥基复合材料(UHTCC)的高温后残余力学性能进行了实验研究,探讨了控制粉煤灰变量下高温对于其抗折强度以及质量损失率的影响,并就劣化机理进行分析。研究结果表明:粉煤灰含量对于质量损失无明显影响,而高温后粉煤灰含量对抗折强度损失有一定的影响,在200℃之前,粉煤灰含量较少组抗折强度损失率为7.5%,粉煤灰含量较多组抗折强度损失率为2.7%;400℃到600℃之间,高粉煤灰含量有效提高抗折强度;800℃后高粉煤灰含量组抗折强度损失明显,粉煤灰含量的增加可以在一定程度上提高UHTCC高温后的力学性能。     

新疆地区推广使用粉煤灰路面砖的研究

0 前言 近年来,许多城市的人行道、停车场、绿化带、广 场及住宅小区道路都铺设了各种形式的彩色路面 砖,路面砖的色彩鲜艳,形式多样,成为城市建设中 亮丽的风景线,特别是近两年来,对路面砖的需求量 逐年上升,生产企业面临着如何提高质量,降低成 本,对传统的生产工艺进行技术创新,以提高产品的     

不同掺量粉煤灰对混凝土力学性能影响的研究

以粉煤灰掺量作为单一变量,通过横向分析与纵向对比试验,得出了粉煤灰对混凝土力学性能的影响,结果表明:粉煤灰等量取代水泥时,随着掺量的增大,混凝土的早期抗压和抗折强度都越来越小;粉煤灰超量取代时,随着掺量的增大,混凝土的早期抗压和抗折强度先增大后减小;经分析,超量取代系数为1.2,取代比不超过20%时,粉煤灰超量取代比等量取代效果好。     

粉煤灰地聚物的力学性能及其化学分析

通过实验对粉煤灰地聚物的力学性能及水化产物成分进行了研究,得出了最佳制备工艺参数,并利用FTIR和DTA/TG表征手段对不同龄期粉煤灰地聚物的凝胶体作了分析,表明在水化过程中粉煤灰内玻璃体发生了解聚—缩聚反应,主要形成N-A-S-H产物。     

利用湖泊淤泥掺粉煤灰生产平瓦

介绍湖泊淤泥掺配粉煤灰平瓦生产过程中原料的处理、混合料的掺配与陈化、坯体成型与干燥、码窑与焙烧等工艺及操作技术.     

Basic rheological and mechanical properties of high-volume fly ash grouts

Soil, rock and oil-well grouting require enormous amounts of cement and are therefore good examples of areas where high volumes of fly ash could replace cement partially to produce low-cost, environmentally friendly and durable grouts. This paper presents the results of the particle size distribution, three rheological properties (flow time, bleeding and setting time), and five mechanical and strain properties (compressive strength, shear bond strength, modulus of elasticity, Poisson's ratio and drying shrinkage) of high-volume fly-ash (HVFA) grouts (cement replacement by fly ash of over 55% by weight), with and without superplasticizer (SP) and/or anti-washout agent (AWA). Rheological properties are reported for eight water–cementitious materials (cement+fly ash) ratios (W/CM), ranging from 0.4 to 1.3, whereas mechanical and strain properties of hardened grouts are given at W/CM of 0.5, 0.55 and 0.65. The effects of SP and AWA on the flow time of low-W/CM grouts and the stability of high-W/CM grouts were investigated. The results indicate that the addition of fly ash in cement grouts reduces the flow time, improves stability, reduces drying shrinkage, and attains similar compressive and shear bond strengths as pure cement grouts at later ages. Moreover, when SP is used for low-W/CM grouts, the latter destabilizes, and in those cases AWA should be used.     

粉煤灰理化性质及微观形貌研究

利用化学及工业分析、X射线衍射分析、SEM扫描电镜、激光粒度分析等手段,对秦岭发电厂的燃煤副产物粉煤灰样品进行一系列的研究,旨在为粉煤灰的综合利用作以参考。     

粉煤灰颗粒特性对其水泥性能的影响

主要研究了对粉煤灰进行机械力化学活化处理后,不同粉磨时间粉煤灰的颗粒特性和粉煤灰水泥性能的变化,结果表明：随着粉磨时间的增加,粉煤灰颗粒的密度、粒度分布都呈有规律的变化,其矿物结晶程度降低,粉磨5 h时掺量为30%的复合水泥达到了纯硅酸盐水泥的强度值。     

蒸压粉煤灰实心砖砌体力学性能试验研究

通过对蒸压粉煤灰砖与专用砂浆配砌的共24个9砖模型的抗剪强度试验,探索块材及胶结材料对试件受力性能的影响.结果表明,所采用专用砌筑砂浆砌筑的砌体通缝抗剪强度计算设计值小于GB 50003-2001<砌体结构设计规范>规定的相应设计值;对于同等级专用砂浆砌筑的抗剪砌体,由薄灰缝和厚灰缝砌筑的砌体抗剪强度相差不大.建议用砖的抗压强度和折压比两项指标确定蒸压粉煤灰砖的强度等级.本次试验采用的专用砂浆砌筑的砌体通缝抗剪强度无明显提高,建议有针对性地调整砌筑砂浆配合比.     

Effects of fly ash properties on characteristics of cold-bonded fly ash lightweight aggregates

The study presented herein provides a new insight into the effects of physical and chemical properties of the fly ash on the characteristics of the cold-bonded fly ash lightweight aggregates. LWAs were manufactured through the cold-bonding pelletization of two fly ashes differing in their physical and chemical properties. Moreover, one type of the LWAs was surface treated by water glass. The produced fly ash aggregates were then examined by means of ESEM micrograph, EDX spectrum, and XRD pattern to resolve the microstructural and the mineralogical characteristics of the LWAs. The findings of the study revealed that the fly ash with higher specific surface and with lower CaO content yielded higher strength LWAs. Furthermore, the surface treatment with water glass provided a marked increase in the aggregate strength and a reduction in the water absorption. The LWCs made with such LWAs had a compressive strength of as high as 60 MPa.     

Effect of silica fume and expanded perlite addition on the technical properties of the fly ash–lime–gypsum mixture

The main objective of this research was to investigate the effect of different type of pozzolan additions to cement free lightweight block made from fly ash–lime–gypsum mixture and observe the changes in physical, mechanical, thermal properties and microstructure. Thermal conductivity of the fly ash–lime–gypsum mixture was improved by the addition of the expanded perlite. Optimal strength-thermal conductivity combination was obtained by the usage of silica fume and expanded perlite together. Improved strength properties were obtained by using hydrothermal curing conditions and superplasticizer addition.     

粉煤灰对轻骨料混凝土性能的影响

为了探究粉煤灰的掺入对轻骨料混凝土的影响,采用外掺0%、15%、20%、30%、50%的粉煤灰代替等量的水泥制作浮石混凝土,研究不同掺量粉煤灰的浮石轻骨料混凝土在28~90d养护龄期间强度变化情况,并对养护28d的试块进行了快速冻融循环试验,通过试块的抗压强度、动弹模量及破坏特征,研究粉煤灰的掺入对轻骨料混凝土抗压强度及抗冻性能的影响。结果表明:粉煤灰的掺入对轻骨料混凝土60d的抗压强度影响较大,能大幅度提高轻骨料混凝土强度,20%的粉煤灰掺入为最优粉煤灰掺量;粉煤灰的掺入还能提高轻骨料混凝土的抗冻性,当掺量不超过30%时,均表现出比基准组好的抗冻性,而过多的掺入则使抗冻性降低。     

Effect of Granulated Blast Furnace Slag and fly ash addition on the strength properties of lightweight mortars containing waste PET aggregates

In this work, the effect of Granulated Blast Furnace Slag (GBFS) and fly ash (FA) addition on the strength properties of lightweight mortars containing waste Poly-ethylene Terephthalate (PET) bottle aggregates was investigated. Investigation was carried out on three groups of mortar specimens. One made with only Normal Portland cement (NPC) as binder, second made with NPC and GBFS together and, third made with NPC and FA together. The industrial wastes mentioned above were used as the replacement of cement on mass basis at the replacement ratio of 50%. The size of shredded PET granules used as aggregate for the preparation of mortar mixtures were between 0 and 4 mm. The waste lightweight PET aggregate (WPLA)–binder ratio (WPLA/b) was 0.60; the water–binder (w/b) ratios were determined as 0.45 and 0.50. The dry unit weight, compressive and flexural–tensile strengths, carbonation depths and drying shrinkage values were measured and presented. The results have shown that modifying GBFS had positive effects on the compressive strength and drying shrinkage values (after 90 days) of the WPLA mortars. However, FA substitution decreased compressive and flexural–tensile strengths and increased carbonation depths. Nevertheless a visible reduction occurred on the drying shrinkage values of FA modifying specimens more than cement specimens and GBFS modified specimens. The test results indicated that, GBFS has a potential of using as the replacement of cement on the WPLA mortars by taking into consideration the characteristics. But using FA as a binder at the replacement ratio of 50% did not improve the overall strength properties. Although it was thought that, using FA as binder at the replacement ratio of 50% for the aim of production WPLA concrete which has a specific strength, would provide advantages of economical and ecological aspects.