钢渣砂粉煤灰砌筑砂浆的研制

文中利用经蒸汽处理制成的钢渣胶凝细集料,与水泥、粉煤炭一起配制砌筑砂浆。结果表明:钢渣砂粉煤灰砌筑砂浆比用水泥、石灰膏、砂配制的普通砂浆强度高,水泥用量少。其主要机理是:钢渣具有一定胶凝特性,且碱度高,对粉煤灰水化具有激活性,并与水泥粉煤浆胶结成一整体。     

污泥-稻壳-木屑混烧灰胶凝性能及重金属浸出特性研究

利用污泥-稻壳-木屑混烧灰、钢渣粉以及水泥等材料制备复合胶凝材料,研究了该胶凝材料胶砂的工作性能、物理力学性能、水化热、水化产物以及重金属毒性浸出特性。结果表明,混烧灰与钢渣粉的掺入改变了水泥胶砂的工作性能,与纯水泥试件相比,复合胶凝材料胶砂的抗压、抗折强度均有所降低,混烧灰掺量不宜超过50%。替代材料的掺入使得水化的诱导期延长,主放热峰向右偏移,推迟胶凝材料的水化过程。由于火山灰效应的存在,使复合胶凝材料体系的累积水化放热量增大。XRD分析表明,复合胶凝材料的水化产物主要为无定形相,复合胶凝材料的自胶凝固化作用抑制了混烧灰中主要重金属元素的迁移性,浸出浓度指标均符合GB 8978—1996《污水综合排放标准》要求。     

钢渣细集料在混凝土路面中的应用研究

钢渣细集料 复合矿渣微粉作为混凝土的胶结材，按照水泥胶砂强度的检验方法，测定胶结材强度，配制路面施工混凝土，进行胶结材与水泥对比性能试验，观察其水化及微观结构，分析钢渣细集料界面反应状况，验证路面质量。     

利用钢渣生产混凝土空心砌块的研究

对用钢渣生产混凝土空心砌块进行了研究。研究结果表明:钢渣的活性较低,若用其生产砌块,必须对其活性进行激发。芒硝对钢渣的活性激发效果较好。用402.5级水泥,58%磨细钢渣,2%的芒硝配制的胶凝材料28d抗压强度达22.5MPa,利用该胶凝材料、破碎的钢渣作粗集料、河砂作细集料,制成的空心砌块强度等级达MU10,且耐久性满足GB8239—97要求。     

不同水化热测试方法对复合胶凝体系测试结果的分析研究

选用溶解热法和TAM AIR热导式等温量热仪测试法对粉煤灰、矿渣粉不同掺量的复合胶凝体系进行了水泥水化热测试试验。试验结果表明,较溶解热法而言,TAM AIR测试法测试精度高、试验误差小,能精确测量水泥基胶凝材料水化放热,适用于复合胶凝体系水化放热测试试验。     

激发剂对钢渣胶凝材料性能的影响

以钢渣、矿渣、水泥熟料为主要原料,并掺入少量激发剂,成功制备了高强、高钢渣掺量的钢渣胶凝材料.探讨了激发剂、熟料掺量、钢渣掺量对钢渣胶凝材料性能的影响,并通过SEM,XRD分析了激发剂对钢渣胶凝材料浆体水化产物及水泥石微观结构的作用.结果表明:激发剂显著提高了钢渣的活性,从而大幅度提高了钢渣胶凝材料的早期性能;掺加激发剂后,钢渣胶凝材料3 d抗压强度可增加119.7%;激发荆对钢渣胶凝材料浆体水化产物种类的影响不大;与硅酸盐水泥浆体相比,钢渣胶凝材料浆体中C-S-H凝胶和Aft晶体含量明显增多,Ca(OH)2晶体含量显著降低.     

大掺量固废胶凝材料制备C50高耐磨路面混凝土

为了大规模消纳钢铁冶炼渣,实现其高附加值利用,并改善因重载交通造成普通混凝土路面严重磨损和劣化的现状,采用钢渣和矿渣作为主要胶凝材料,在少量水泥熟料的激发作用下,研究矿渣与钢渣的掺比对钢渣-矿渣复合胶凝材料力学性能及耐磨性能的影响规律,并采用XRD、FTIR及SEM对胶凝体系的水化产物及微观形貌进行分析。结果表明,以GBFS∶SS=2.0为分界线,混凝土抗压强度的增长速率减弱而耐磨性能下降;不同矿渣与钢渣掺比的复合胶凝体系水化产物均为C-S-H(C-A-S-H)凝胶、CH及CaCO3,此外还含有少量未反应完全的C2S和C3S,及不参与水化的RO相和C2F;少量水泥的激发作用,可以促进矿渣与钢渣的协同水化,增加微细颗粒间的结合力,提高分子网络的聚合度,而RO相和C2F作为微细集料填充孔隙并改善界面过渡区结构。     

利用工业废渣制备新型墙体材料

以磨细矿渣、原状脱硫渣和炉渣为基本组成,掺入水泥熟料和石灰激发剂配成复合胶凝材料,粒状工业废渣为细集料制备新型墙体材料。通过配合比设计、强度测试,探讨了激发剂含量和不同工业废渣细集料对新型墙材强度的影响,确定了复合胶凝材料及墙体砌块的配比;并通过XRD、SEM等测试手段,分析了复合胶凝材料的主要水化产物及微观结构。     

钢渣微粉水化性能研究

将钢渣微粉以不同的掺量掺入水泥中进行砂浆实验与水化热实验,研究钢渣微粉潜在胶凝性的发展。结果表明:钢渣微粉的掺入会降低水泥的胶凝性能,但钢渣微粉水化后期的潜在胶凝性比水泥高。钢渣微粉可以提高砂浆的流动度、折压比,大幅降低水泥的水化热。     

钢渣微粉水化性能研究

将钢渣微粉以不同的掺量掺入水泥中进行砂浆实验与水化热实验,研究钢渣微粉潜在胶凝性的发展。结果表明:钢渣微粉的掺入会降低水泥的胶凝性能,但钢渣微粉水化后期的潜在胶凝性比水泥高。钢渣微粉可以提高砂浆的流动度、折压比,大幅降低水泥的水化热。     

超高强混凝土用低水胶比浆体的水化热研究

采用自行改进的水化热测定系统,研究了粉煤灰、矿渣粉和水胶比对超高强混凝土用低水胶比浆体水化热和水化进程的影响规律.结果表明:掺10%(质量分数,下同)粉煤灰或矿渣粉不影响低水胶比浆体的水化进程;掺30%,50%粉煤灰或矿渣粉均使低水胶比浆体的水化温升和水化放热速率峰值明显降低,并延缓这些峰值出现的时间,且粉煤灰对水化进程的延缓效果优于同等掺量的矿渣粉;提高水胶比只能略微推迟浆体的水化温升和水化放热速率峰值出现的时间,使水化放热速率峰值有所增大,不会改变浆体温升曲线和放热速率曲线的形状.     

掺矿粉混凝土耐久性研究

本文介绍了掺矿粉混凝土的耐久性,重点研究了掺加矿粉对混凝土水化热、抗水渗透性能、抗氯离子渗透性能、抗碳化性能以及抗冻性能的影响。研究结果表明：混凝土中掺加矿粉,可降低浆体水化热;大幅提高混凝土的抗水渗透性能;显著提高混凝土抗氯离子渗透性能,尤其是采用矿粉和粉煤灰复配技术并结合引气剂的使用;在同强度的条件下掺矿粉混凝土和普通混凝土具有相同的抗碳化作用能力;在强度和含气量相同的条件下掺矿粉混凝土和普通混凝土具有相同的抗冻融能力。     

粒化高炉矿渣粉在混凝土施工中的应用

结合工程实例,综述了粒化高炉矿渣粉在混凝土施工中的应用,从强度、使用性能、经济效益、社会效益以及混凝土水化热等方面对两种配合比混凝土试验结果进行了对比分析,阐明了该材料的可行性.     

Modeling of hydration kinetics in cement based materials considering the effects of curing temperature and applied pressure

Portland cement is the most widely used cement in the world. In the industrial by-products suitable for use as mineral admixtures in Portland concrete are ashes produced from the combustion of coal and granulated slag in metal industries. However, comparing such ashes with Portland cement, determining the hydration of this concrete is much more complex because of the reaction between calcium hydroxide and fly ash or slag. In this paper, the production of calcium hydroxide in cement hydration and its consumption in the reaction of mineral admixtures are considered in order to develop a numerical model for simulating the hydration of concrete, which contains fly ash or slag. The proposed numerical model includes the effects of water to binder ratios, slag or fly ash replacement ratios, curing temperature, and applied pressure. The heat evolution rate of fly ash- or slag-blended concrete is determined by the contribution of both cement hydration and the reaction of mineral admixtures. Furthermore, an adiabatic temperature rise in hardened blended concrete is evaluated based on the degree of hydration of the cement and mineral admixtures. The proposed model is verified through experimental data obtained from the concrete with different water-to-cement ratios and mineral admixture substitution ratios at elevated temperature and high pressure.     

铜渣粉-水泥复合胶凝体系的水化热及动力学研究

采用等温量热法,分别测定了铜渣粉磨时间为30、60min,掺量为0%、20%、30%和40%的铜渣粉水泥复合胶凝体系的水化放热速率和放热量,分析了铜渣粉细度和掺量对复合胶凝体系水化反应历程的影响,并且基于Kstulovic Dabic模型计算得到了水化动力学参数.结果表明：铜渣粉推迟了复合胶凝体系的诱导期结束时间、加速期开始时间以及第2放热峰出现时间,降低了复合胶凝体系水化放热量及水化速率;水化12h前,铜渣粉对复合胶凝体系水化热呈抑制作用;水化12h后,铜渣粉活性逐渐被激发,水化速率加快;铜渣粉水泥复合胶凝体系的水化反应经历结晶成核与晶体生长相边界反应扩散作用（NG I D）过程,由Kstulovic Dabic水化动力学模型计算得到的铜渣粉水泥复合胶凝体系水化反应速率曲线,能够较好地分段模拟由量热试验得到的水化速率曲线;复合胶凝体系的结晶成核与晶体生长（NG）过程随铜渣粉掺量的增加和细度的降低而延长,相边界反应（I）过程随铜渣粉掺量的增加而缩短.     

Calcium sulfate hemihydrate activated low heat sulfate resistant cement

Investigations were undertaken to produce low heat sulfate resistant cement by activation of granulated slag obtained from the blast furnace process of iron making and phosphate industries with the calcium sulfate hemihydrate. Experimental data showed that cement gives fast setting characteristics in addition to high strength development. The setting time of cement was regulated with a small addition of set retarder without adversely affecting the strength development of cement. It is noted that beta hemihydrate plaster gives better strength results than the anhydrite activated cement. The results also confirm that granulated blast furnace slag can be replaced with phosphatic slag up to 10% by mass without loosing strength. DTA and X-ray diffraction analysis have been used to identify the hydration products formed in the hydrated cement. The heat of hydration data of cement is reported in the paper.     

Splitting tensile strength of concrete using ground granulated blast furnace slag and SiO2 nanoparticles as binder

In the present study, split tensile strength together with pore structure, thermal behavior and microstructure of concrete containing ground granulated blast furnace slag and SiO₂ nanoparticles have been investigated. Portland cement was replaced by different amounts of ground granulated blast furnace slag and the properties of concrete specimens were measured. Although it negatively impacts the properties of concrete at early ages, ground granulated blast furnace slag was found to improve the physical and mechanical properties of concrete up to 45 wt% at later ages. SiO₂ nanoparticles with the average particle size of 15 nm were partially added to concrete with the optimum content of ground granulated blast furnace slag and physical and mechanical properties of the specimens were studied. SiO₂ nanoparticle as a partial replacement of cement up to 3 wt% could accelerate C-S-H gel formation as a result of increased crystalline Ca(OH)₂ amount at the early age of hydration and hence increase split tensile strength of concrete specimens. The increased the SiO₂ nanoparticles’ content more than 3 wt% causes the reduced the split tensile strength because of the decreased crystalline Ca(OH)₂ content required for C-S-H gel formation. SiO₂ nanoparticles could improve the pore structure of concrete and shift the distributed pores to harmless and few-harm pores.     

矿渣微粉在水泥混凝土中应用的概述

对用作混凝土掺合料的矿渣微粉的主要技术条件与矿渣微粉混凝土的主要性能特征作了简要的介绍。对矿渣微粉用于混凝土中的工作机理进行了探讨。最后提出矿渣微粉在水泥制品生产中应得到开发应用。     

磨细锂渣粉对新拌混凝土性能的影响

锂渣是新疆大量排放的固体工业废弃物,作为活性掺合料应用于混凝土中,一方面可减少其排放和堆存量,有利于改善环境;另一方面,锂渣粉也能有效改善和提高混凝土的性能.通过研究不同比表面积的磨细锂渣粉对混凝土新拌性能的影响.从凝结时间、坍落度保持、常压泌水率和压力泌水率的试验结果综合,比表面为597 m2/kg的磨细锂渣粉取代混...     

钢纤维矿渣混凝土性能试验研究

研究了掺入钢纤维和磨细矿渣对混凝土性能的影响,综合分析了钢纤维体积率、矿渣掺量和水胶比等因素与混凝土强度的关系。正交试验结果表明,钢纤维掺量对混凝土劈裂抗拉强度影响显著,矿渣也是明显影响因素,在合适的水胶比条件下,掺入矿渣的钢纤维混凝土和易性良好,力学性能比素混凝土有较大提高,满足支护要求。