摘要
为提高赤泥、矿渣等固废资源的利用率,本研究以赤泥、矿渣和超细氧化钙为主要原料制备了地聚物胶凝材料(C-R-S地聚物);研究了氧化钙添加量、赤泥添加量、激发剂(水玻璃)模数、激发剂(水玻璃)添加量、水胶比及养护温度对C-R-S地聚物力学性能的影响;借助扫描电子显微镜(SEM)、三维CT、热活性微量热仪、X射线衍射(XRD)、傅里叶变换红外光谱仪(FTIR)等对其微观结构和聚合机理进行分析.结果表明:超细氧化钙的掺入增强了C-R-S地聚物的力学性能.当赤泥掺量为40%、超细氧化钙掺量为5%、激发剂模数1.25、激发剂用量20%、水胶比0.45时其力学性能最佳,抗压强度达到71.4 MPa,抗折强度达到9.2 MPa.高温养护能够提高地聚物力学性能.C-R-S地聚物微观形貌呈带有纳米小孔的片层状结构,三维CT下其孔洞和裂缝较小.热流演变分析表明,超细CaO的掺入能够使水化放热提前发生,加速了体系的聚合反应.XRD和FTIR分析表明,C-R-S地聚物中主要以方解石、索伦石、赤铁矿、钙霞石、C2S、C3S等形式存在,过程中形成了大量C-S-H地聚物水化产物.
Abstract
In order to improve the utilization rate of red mud,slag and other solid waste resources,geopolymer cementing materials(C-R-S geopolymer)with red mud,slag and superfine calcium oxide as main raw materials was prepared.The effects of calcium oxide content,red mud content,activator(sodium silicate)modulus,activator(sodium silicate)content,water-binder ratio and curing temperature on the properties of geopolymer were studied.The microstructure and polymerization mechanism were analyzed by scanning electron microscope(SEM),three-dimensional CT,thermoactive microcalorimetry,X-ray diffraction(XRD)and Fourier transform infrared spectrometer(FTIR).The results showed that the mechanical properties of C-R-S geopolymer were enhanced by the addition of ultrafine CaO.When the content of red mud is 40%,the content of ultrafine calcium oxide is 5%,the modulus of activator is 1.25,the content of activator is 20%,and the water-binder ratio is 0.45,its mechanical properties are the best,with a compressive strength of 71.4 MPa and a flexural strength of 9.2 MPa.High temperature curing can improve the mechanical properties of C-R-S polymer.The microscopic morphology of C-R-S geopolymer is a lamellar structure with nanoholes,and the holes and cracks are small under three-dimensional CT.The analysis of heat flow evolution shows that the addition of ultrafine CaO can advance the heat release of hydration and accelerate the polymerization of the system.XRD and FTIR showed that the C-R-S geoplymer mainly existed in the form of calcite,suolunite,hematite,calcium nephelite,C2S,C3S.Many hydration products of C-S-H were formed in the hydration process.
基金项目
广西科技重大专项资助项目(桂科AA22068077)
广西科技重大专项资助项目(杜科AA22068078)
广西重点研发计划资助项目(桂科AB21196046)
国家科技期刊平台
NSTL
万方数据