Degradation resistance of different cementitious materials to phosphoric acid attack at early stage

被引：0

作者：

Ren, Jie ^{[1
,2
]}

Zhang, Lihai ^{[1
]}

Walkley, Brant ^{[3
]}

Black, Jay R. ^{[4
]}

San Nicolas, Rackel ^{[1
]}

机构：

[1] Department of Infrastructure Engineering, The University of Melbourne, Victoria,3010, Australia

[2] Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, College of Civil and Transportation Engineering, Shenzhen University, Shenzhen,518060, China

[3] Department of Chemical and Biological Engineering, The University of Sheffield, Sheffield,S1 3JD, United Kingdom

[4] School of Earth Sciences, Peter Cook Centre for CCS Research, The University of Melbourne, VIC,3010, Australia

来源：

Cement and Concrete Research | 2022年 / 151卷

关键词：

Acid attack - Alkali activated slags - Alkali-activated slag/fly ash binder - Cementitious materials - Degradation process - Degradation resistance - Early stage - Geopolymer - Kinetic of degradations - Mass ratio;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

Sewer wastewater systems pose great threats to OPC-based concretes used for pipes due to the presence of various acids. Phosphoric acid can cause as much damage as sulphuric acid but has been very lightly studied. This study focuses on the early stage of the degradation process of different cementitious materials in phosphoric acid. Three types of cementitious materials are compared: OPC (100% cement), slag-blended OPC (slag/cement mass ratio at 65/35) and alkali-activated slag/fly ash pastes (slag/fly ash mass ratio at 50/50). Samples were exposed to phosphoric acid solution with a constant pH at 2.0 ± 0.2 for 44 days. The degradation kinetics, chemical and microstructural properties as well as dissolution rate of these binders are analysed. The results show that the alkali-activated slag/fly ash binder has the lowest degradation rate compared to the other cement-based binders. The intrinsic characteristics of the binders lead to significant changes in the kinetics of degradation. The chemical properties of the binders are the critical influential factor of the early stage behaviour. A conceptual degradation process is proposed to describe the early-stage kinetics of degradation for the cementitious materials studied. © 2021

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