含有速凝剂与高吸水性聚合物（SAPs）混合的水泥浆体的凝结特性、力学性能和微观结构：一项结合其他方法的核磁共振研究

Setting Characteristics, Mechanical Properties and Microstructure of Cement Pastes Containing Accelerators Mixed with Superabsorbent Polymers (SAPs): An NMR Study Combined with Additional Methods.

作者信息

Ji Yanliang, Sun Zhenping, Chen Chao, Pel Leo, Barakat Ahmed

机构信息

Key Laboratory of Advanced Civil Engineering Materials, Ministry of Education, Tongji University, Shanghai 201804, China.

School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.

出版信息

Materials (Basel). 2019 Jan 20;12(2):315. doi: 10.3390/ma12020315.

DOI:10.3390/ma12020315

PMID:30669526

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6356829/

Abstract

In this study, the setting property and mechanical strength of cement pastes containing accelerators (CPCA) with or without superabsorbent polymers (SAPs) were first studied. The early microstructure evolution and water distribution at 7 and 28 days were probed by 1D (₂) and 2D (₁-₂ maps) H¹ nuclear magnetic resonance (NMR) relaxometry, and the microstructure was systematically investigated by using mercury intrusion porosimetry (MIP), back-scattered electron (BSE) image and energy-dispersive X-ray spectroscopy (EDX) analysis. Results showed that the SAPs in the cement paste containing accelerators had various influences on setting time and compressive strength depending on the type of accelerators. The presence of SAPs in the cement paste containing alkaline free accelerators could alleviate the decrease of internal relative humidity, promote hydration and help to modify the pore structure. Moreover, it was observed that the SAP cavities could be nicely filled with calcium hydroxide (CH) in the cement paste with alkaline free accelerators.

摘要

在本研究中，首先研究了含或不含超吸水性聚合物（SAPs）的含促凝剂水泥浆体（CPCA）的凝结性能和力学强度。通过一维（₂）和二维（₁-₂图谱）¹H核磁共振（NMR）弛豫测量法探测了7天和28天时的早期微观结构演变和水分分布，并使用压汞法（MIP）、背散射电子（BSE）图像和能量色散X射线光谱（EDX）分析对微观结构进行了系统研究。结果表明，含促凝剂水泥浆体中的SAPs对凝结时间和抗压强度有不同影响，这取决于促凝剂的类型。含无碱促凝剂的水泥浆体中SAPs的存在可以缓解内部相对湿度的降低，促进水化并有助于改善孔隙结构。此外，观察到在含无碱促凝剂的水泥浆体中，SAP孔洞可以很好地被氢氧化钙（CH）填充。