共查询到19条相似文献,搜索用时 234 毫秒
1.
2.
以粉煤灰(FA)、铸造旧砂热法再生粉尘(DHRS)为原料,在水玻璃型碱性激发液的激发作用下研究制备了DHRS-FA地质聚合物材料(铸造旧砂热法再生粉尘-粉煤灰基地质聚合物材料).为了探讨不同的养护工艺对DHRS-FA地质聚合物材料强度的影响,研究了自然养护、湿养养护、高温蒸养(40℃、60℃、80℃)养护对地质聚合物强度的影响.结果表明:试样在高温养护工艺下,其早期抗压强度形成较快,且优于自然养护和湿养养护工艺下试样形成的抗压强度;试样在高温养护工艺下,中期和后期抗压强度趋于自然养护试样的抗压强度;而湿养条件下养护的试样抗压强度最差. 相似文献
3.
4.
粉煤灰-垃圾焚烧飞灰二元地聚合物的制备研究 总被引:2,自引:0,他引:2
采用正交设计对PSS型地聚合物的配合比进行了优化,发现其最优配合比为:SiO2:Al2O3=4.0,Na2O:Al2O3=1.1,H2O:Na2O=6.8。研究了粉煤灰细度、垃圾焚烧飞灰掺量、养护温度对粉煤灰-垃圾焚烧飞灰二元地聚合物物理力学性能和工作性能的影响。试验结果表明:(1)粉煤灰经机械激发后,能显著提高地聚合物的抗压强度。以平均粒径为25.44μm的粉煤灰制备地聚合物,其14d抗压强度比未经机械激发的提高了84%;(2)采用等量取代法在粉煤灰中掺入5%垃圾焚烧飞灰制备的粉煤灰-垃圾焚烧飞灰二元地聚合物的抗压强度下降不明显并且能抑制强度倒缩现象;(3)提高养护温度可以明显提高地聚合物的早期强度,但对后期强度影响很小。在60℃养护的地聚合物3 d、7 d抗压强度比23℃养护的分别提高了67.9%和33.9%,而28 d抗压强度仅提高了4%。另外,较低的养护温度有助于地聚合物获得更高的表观密度。 相似文献
5.
6.
7.
8.
以赤泥、粉煤灰为主要原料,采用水玻璃作为碱激发剂,制备出一种具有较高早期强度的免烧成矿物聚合物胶凝材料.通过实验初步探讨了碱激发剂对该矿物聚合物强度发展的影响.利用合适配比的赤泥/粉煤灰胶凝材料作为基质原料,用细沙作骨料,制成了一种赤泥/粉煤灰基矿物聚合物免烧材料.当赤泥的加入量在60%~70%范围时,各组试样的3 d抗压强度均在10 MPa以上,符合非承重墙体建筑材料的强度MU10级要求.同时本文还对该矿物聚合物材料中胶凝反应机理进行了初步探讨. 相似文献
9.
10.
11.
为得到室温下粉煤灰与碱激发剂质量比、水玻璃与氢氧化钠溶液质量比和氢氧化钠溶液摩尔浓度对粉煤灰地质聚合物力学性能的影响,以低钙粉煤灰为原料,制备了地质聚合物胶凝材料。采用正交试验方法,分析粉煤灰地质聚合物抗压强度,探讨碱激发剂配比对粉煤灰地质聚合物力学性能的影响,结合SEM、XRD和FTIR对试样进行表征,并对该材料的应力-应变曲线进行了研究。结果表明:粉煤灰地质聚合物的抗压强度随着激发剂掺量的减少而增大,水玻璃在激发剂中的比值与粉煤灰地质聚合物的抗压强度呈现正相关,其中粉煤灰与碱激发剂质量比为1.8,水玻璃与氢氧化钠溶液质量比为2.5且氢氧化钠溶液的浓度为10 mol/L时,120 d龄期的抗压强度可达51.98 MPa。对应力-应变曲线分析得出,在一定程度上,激发剂的掺入量对粉煤灰地质聚合物的破坏应变和弹性模量有较大影响。SEM、XRD和FTIR分析表明随着养护时间增长,胶凝材料体系内结构更致密,生成了更多的硅铝酸盐凝胶。 相似文献
12.
13.
研究利用高炉矿渣(BFS)、粉煤灰(FA)作为原材料制备地质聚合物。以氢氧化钠与水玻璃作为碱激发剂,在碱激发条件下制备地质聚合物固化二价铅离子(Pb2+)。研究Pb2+的掺量对固化体强度的影响,并通过浸出毒性实验、X射线衍射分析(XRD)、红外光谱分析(FT-IR)、扫描电镜(SEM)等表征分析、防辐射实验测试,探究其固化效果与固化机理。结果表明,高炉矿渣-粉煤灰基地质聚合物与Pb2+具有良好的相容性,且固化体在28 d最高抗压强度可以达到43 MPa,Pb2+的添加质量分数为1%时能提高其固化体的强度。浸出实验表明,固化体对质量分数为1% Pb2+的固化效率在97%以上。微观分析认为大部分重金属是以羟基配合离子的形式被物理封装在地质聚合物内部。防辐射实验测试表明,Pb2+的掺量与高炉矿渣-粉煤灰基地质聚合物的γ射线屏蔽效果成正相关,实验中Pb2+最优掺入质量分数为3%,线性吸收系数和半衰减层厚度最优值分别为0.222 0 cm-1和2.309 5 cm。 相似文献
14.
《Ceramics International》2023,49(2):2091-2101
Designing a building material with excellent heat resistance is crucial for protection against catastrophic fires. Geopolymer materials have been investigated as they offer better heat resistance than traditional cement owing to their ceramic-like properties. Curing temperature and conditions are crucial factors that determine the properties of geopolymers, but their impacts on the heat resistance of geopolymers remain unclear. This study produced geopolymers from fly ash and ground granulated blast furnace slag by using sodium silicate and sodium hydroxide solutions as alkaline solutions. To examine the effect of curing conditions on the high-temperature performance of geopolymer, four different curing conditions, namely, heat curing (70 °C for 24 h), ambient curing (20 °C), water curing, and the combination of heat and water curing (70 °C for 24 h followed by water curing), were applied. At 28 d, the specimens were subjected to high temperatures (500 °C, 750 °C, and 950 °C), and their mechanical and microstructural evolutions were studied. The results revealed that the curing condition significantly affects the properties of the unexposed geopolymer; the effect on its high-temperature performance is insignificant. Furthermore, all the specimens could maintain adequate compressive strength after exposure to the maximum temperature of 950 °C, promising the use of geopolymer for structural applications. 相似文献
15.
为将页岩提钒尾渣资源化,利用页岩提钒尾渣作为主要原料,偏高岭土为铝质辅料制备地聚合物。考察了成型方式、硅铝原料配比、碱激发剂种类、碱激发剂用量和成型压力对地聚合物试样抗压强度的影响。结果表明,地聚合物制备最佳条件为:原料的质量配比(尾渣/偏高岭土)为11:9,NaOH碱激发剂质量分数为10%,水固比为0.18,成型压力为20 MPa,试样14 d抗压强度可达58.25 MPa。通过XRD、FTIR、TG-DSC、SEM和孔径分析对地聚合物试样进行检测表征,分析表明,地聚合反应的主要产物为无定形硅铝凝胶和少量钠沸石,无定形硅铝凝胶可以改善试样的孔结构,增强试样微观结构致密度,宏观表现为试样抗压强度增大。 相似文献
16.
采用钢渣微粉和粉煤灰为主要原材料制备地质聚合物,以抗压强度为指标优化制备条件,探讨影响地质聚合物强度的因素,利用SEM、XRD和TG-DSC等手段对产物的微观形貌、物相组成和热稳定性进行分析表征。研究表明,地质聚合物的抗压强度随着钢渣微粉掺量和激发剂掺量增加先增加后减小,随温度增加而增加,其中养护温度影响最显著,水玻璃模数影响最小。最佳工艺条件为:水玻璃模数1.0、激发剂掺量20%(质量分数)、钢渣微粉掺量20%(质量分数)、液固比0.3、养护温度60 ℃。其3 d和7 d抗压强度高达40.11 MPa和43.03 MPa,固化Pb2+后对其强度影响较小,固化率在99.99%以上。地质聚合物表面致密度高,无明显裂纹,未观察到明显的钢渣颗粒轮廓,晶相结构主要为石英和莫来石,热稳定好。 相似文献
17.
《Ceramics International》2022,48(10):14076-14090
Environmental issues caused by glass fiber reinforced polymer (GFRP) waste have attracted much attention. The development of cost-effective recycling and reuse methods for GFRP composite wastes is therefore essential. In this study, the formulation of the GFRP waste powder replacement was set at 20–40 wt%. The geopolymer was formed by mixing GFRP powder, fly ash (FA), steel slag (SS) and ordinary Portland cement (OPC) with a sodium-based alkali activator. The effects of GFRP powder content, activator concentration, liquid to solid (L/S) ratio, and activator solution modulus on the physico-mechanical properties of geopolymer mixtures were identified. Based on the 28-day compressive strength, the optimal combination of the geopolymer mixture was determined to be 30 wt% GFRP powder content, an activator concentration of 85%, L/S of 0.65, and an activator solution modulus of 1.3. The ratios of compressive strength to flexural strength of the GFRP powder/FA-based geopolymers were considerably lower than those of the FA/steel slag-based geopolymers, which indicates that the incorporation of GFRP powder improved the geopolymer brittleness. The incorporation of 30% GFRP powder in geopolymer concrete to replace FA can enhance the compressive and flexural strengths of geopolymer concrete by 28%. After exposure to 600 °C, the flexural strength loss for geopolymer concretes containing 30 wt% GFRP powder was less than that of specimens without GFRP powder. After exposure to 900 °C, the compressive strength and flexural strength losses of geopolymer concretes containing 30 wt% GFRP powder were similar to those of specimens without GFRP powder. The developed GFRP powder/FA-based geopolymers exhibited comparable or superior physico-mechanical properties to those of the FA-based geopolymers, and thus offer a high application potential as building construction material. 相似文献
18.
以工业固体废弃物富镁镍渣和粉煤灰为原料,以水玻璃和NaOH为碱激发剂,制备了一系列富镁镍渣-粉煤灰基地质聚合物。研究了不同粉煤灰掺量对地质聚合物力学性能的影响,并测定地质聚合物的线性收缩和碱溶出,通过XRD、IR、DTA等手段对产物进行表征。结果表明:富镁镍渣-粉煤灰基地质聚合物的强度随粉煤灰的掺入先升高后降低,当掺量为30%(质量分数)时,地质聚合物的抗压强度可达最高值22.15 MPa,较镍渣基地质聚合物强度提高42.2%;XRD分析表明富镁镍渣中MgO以镁橄榄石相存在,而非游离态,故地质聚合物具有良好的体积安定性。 相似文献
19.
The research was carried out to develop geopolymers mortars and concrete from fly ash and bottom ash and compare the characteristics deriving from either of these products. The mortars were produced by mixing the ashes with sodium silicate and sodium hydroxide as activator solution. After curing and drying, the bulk density, apparent density and porosity, of geopolymer samples were evaluated. The microstructure, phase composition and thermal behavior of geopolymer samples were characterized by scanning electron microscopy, XRD and TGA-DTA analysis respectively. FTIR analysis revealed higher degree of reaction in bottom ash based geopolymer. Mechanical characterization shows, geopolymer processed from fly ash having a compressive strength 61.4 MPa and Young's modulus of 2.9 GPa, whereas bottom ash geopolymer shows a compressive strength up to 55.2 MPa and Young's modulus of 2.8 GPa. The mechanical characterization depicts that bottom ash geopolymers are almost equally viable as fly ash geopolymer. Thermal conductivity analysis reveals that fly ash geopolymer shows lower thermal conductivity of 0.58 W/mK compared to bottom ash geopolymer 0.85 W/mK. 相似文献