Effect of synthesis parameters on the development of unconfined compressive strength of recycled waste concrete powder-based geopolymers

doi:10.1016/j.conbuildmat.2021.123264

	Effect of synthesis parameters on the development of unconfined compressive strength of recycled waste concrete powder-based geopolymers
	Huo, Wangwen 1; Zhu, Zhiduo 1; Chen, Wu 2; Zhang, Jie 1; Kang, Zhuanzhuan 1; Pu, Shaoyun 1; Wan, Yu 1
	2021-07-19
发表期刊	CONSTRUCTION AND BUILDING MATERIALS
ISSN	0950-0618
卷号	292
摘要	The main object of this study is to investigate the geopolymerization potential of recycled waste concrete powder (RWCP) as well as the effects of synthesis parameters, including the molarity of NaOH solution, the mass ratio of water glass to NaOH solution (WG/NH), the mass ratio of liquid alkali activator to solid powder (L/S), and the curing conditions (curing temperature, curing time and curing method), on the development of unconfined compressive strength (UCS) of recycled waste concrete powder-based geopolymers. The recycled waste concrete powder (RWCP) (size < 0.075 mm) was utilized as source material, and water glass and sodium hydroxide (NaOH) were used as alkaline activators to synthesize geopolymer specimens. The dissolution of alumino-silicate from the RWCP under different concentrations of alkaline solutions was studied. The UCS of the resulting geopolymers synthesized under different conditions was tested. Further, the microstructure and mineral composition of the final products were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) technology. The results indicate that the dissolution of Si4+ and Al3+ in raw materials (RWCP) was highly affected by the alkali content and dissolution time. Increasing the alkali content, water glass content and L/S ratio was all conducive to enhancing the UCS of geopolymers. The optimum NaOH concentration corresponpded to 14 mol/L, WG/NH ratio of 1.5 and L/S mass ratio of 0.4. A maximum 7-day UCS of 14.32 MPa was achieved by wet curing at 70 degrees C for 24 hours. Microscopic analysis showed that the final products were mainly composed of amorphous hydrated calcium silicate and hydrated sodium aluminosilicate gels. However, due to the low activity and high calcium content of RWCP, most of crystalline phases and some unreacted substances still existed in the end products as inactive fillers, resulting in a relatively low UCS of the synthesized geopolymers. Baded on the research, it can be concluded that RWCP can be recycled as the precursor to synthesize geopolymer binder. (C) 2021 Elsevier Ltd. All rights reserved.
关键词	Recycled waste concrete powder FLY-ASH Geopolymer SILICATE Synthesis parameters TEMPERATURE Unconfined compressive strength AGGREGATE Microstructure CEMENT WATER GEL
DOI	10.1016/j.conbuildmat.2021.123264
收录类别	SCIE
语种	英语
WOS研究方向	Construction & Building Technology ; Engineering ; Materials Science
WOS类目	Construction & Building Technology ; Engineering, Civil ; Materials Science, Multidisciplinary
WOS记录号	WOS:000660296800001
出版者	ELSEVIER SCI LTD
原始文献类型	Article ; Early Access
EISSN	1879-0526
引用统计	被引频次：61[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.library.ouchn.edu.cn/handle/39V7QQFX/168470
专题	国家开放大学江苏分部
通讯作者	Zhu, Zhiduo
作者单位	1.Southeast Univ, Sch Transportat, Nanjing 211189, Jiangsu, Peoples R China; 2.Jiangsu Open Univ, Sch Civil Engn, Nanjing 210019, Jiangsu, Peoples R China
推荐引用方式 GB/T 7714	Huo, Wangwen,Zhu, Zhiduo,Chen, Wu,et al. Effect of synthesis parameters on the development of unconfined compressive strength of recycled waste concrete powder-based geopolymers[J]. CONSTRUCTION AND BUILDING MATERIALS,2021,292.
APA	Huo, Wangwen.,Zhu, Zhiduo.,Chen, Wu.,Zhang, Jie.,Kang, Zhuanzhuan.,...&Wan, Yu.(2021).Effect of synthesis parameters on the development of unconfined compressive strength of recycled waste concrete powder-based geopolymers.CONSTRUCTION AND BUILDING MATERIALS,292.
MLA	Huo, Wangwen,et al."Effect of synthesis parameters on the development of unconfined compressive strength of recycled waste concrete powder-based geopolymers".CONSTRUCTION AND BUILDING MATERIALS 292(2021).