Physical and mechanical properties and micro characteristics of fly ash-based geopolymer paste incorporated with waste Granulated Blast Furnace Slag (GBFS) and functionalized Multi-Walled Carbon Nanotubes (MWCNTs)
Physical and mechanical properties and micro characteristics of fly ash-based geopolymer paste incorporated with waste Granulated Blast Furnace Slag (GBFS) and functionalized Multi-Walled Carbon Nanotubes (MWCNTs)
复制标题
掺有废弃粒状高炉矿渣 (GBFS) 和功能化多壁碳纳米管 (MWCNT) 的粉煤灰基地质聚合物浆体的物理机械性能和微观特性。
DOI：
10.1016/j.jhazmat.2020.123339
复制
发表时间：
2021-01-05
影响因子：
13.6
通讯作者：
Li, Shan
中科院分区：
文献类型：
--
作者：
Li, Faping;Liu, Lisheng;Li, Shan
地质聚合物非常耐用且具有良好的机械性能，因此被视为传统普通波特兰水泥粘合剂的环保替代品。在这项研究中，通过使用硝酸和硫酸的混合物的改性方法获得了多壁碳纳米管，然后使用三种类型的分散剂进行分散。制备粉煤灰基地质聚合物以验证采用 0.05 wt.% 的有效性和可行性。 %、0.10 wt.% 和 0.15 wt.% 功能化 MWCNT，GBFS 的飞灰替代率为 10%-40%。分别使用 FT-IR 和 TEM 表征功能化 MWCNT 在水溶液中的结构和分散性。然后，评估凝结时间、吸水能力和机械性能。此外，还利用SEM-EDS、FT-IR、TG-DSC、Si-29 NMR和XRD对凝胶产物的形貌、元素成分、矿物相和地质聚合度进行了研究。实验结果表明，功能化多壁碳纳米管含有COOH和OH基团，可以均匀分散在含有SDS分散剂的水溶液中。此外，与所有其他地质聚合物浆料相比，掺有 0.1 wt.% 功能化 MWCNT 并用 GBFS 替代飞灰 30% 的地质聚合物浆料表现出更高的压缩和弯曲强度以及更低的吸水能力。
Geopolymers are highly durable and have favorable mechanical properties, and are thus regarded as an eco-friendly alternative to traditional ordinary Portland cement binder. In this study, MWCNTs are obtained through a modification method using a compound of nitric acid and sulfuric acid, and are then dispersed using three types of dispersants. Fly ash-based geopolymers are prepared to validate the effectiveness and feasibility of adopting 0.05 wt. %, 0.10 wt.%, and 0.15 wt.% functionalized MWCNTs and substitution ratios of 10 %-40 % of fly ash with GBFS. The structure and dispersity of the functionalized MWCNTs in aqueous solutions are characterized using FT-IR and TEM, respectively. Then, the setting time, water absorption capacity, and mechanical behaviors are evaluated. In addition, SEM-EDS, FT-IR, TG-DSC, Si-29 NMR, and XRD are employed to investigate the morphology, elemental components, mineralogical phases, and geopolymerization degree of the gel products. The experimental results show that the functionalized MWCNTs comprise COOH and OH groups and can be uniformly dispersed in aqueous solution containing SDS dispersant. Furthermore, geopolymer paste incorporated with 0.1 wt.% functionalized MWCNTs and having 30 % substitution of fly ash with GBFS exhibits a higher compressive and flexural strength and a lower water absorption capacity compared with all other geopolymer pastes.