The pH measurement of cement-based materials: Effect of leaching time, leaching technique and water-to-solid ratio
Document Type
Article
Publication Date
1-12-2024
Abstract
Corrosion of steel is an electrochemical process that is affected by pH and potential difference. The pH of con-crete may change due to physical, chemical, and biological influence over time. Therefore, it is important to measure and monitor the pH of reinforced concrete as a structural health monitoring parameter related to durability. Ex-situ leaching (ESL) method is commonly applied to produce the equilibrated aqueous solutions for the pH measurement of cement-based materials. However, there are limited studies about the effect of leaching time, leaching technique and water-to-solid (w/s) ratio when applying this method. This may lead to underes-timation of pH and unnecessary prolonged leaching time. The solution temperature compensated pH value was used during analysis of the data. By testing on the OPC mortar with cement-to-sand ratio of 1:3 and water-to -cement ratio of 0.55, the optimum w/s ratio and minimum leaching time are 2 and 5 min, respectively. The minimum quantity for solid per sample shall not be less than 5.0 g. The findings of this research will contribute to a more accurate pH measurement and may play a part in regulating a standard for cement-based materials.
Keywords
Ex-situ leaching, ESL, Alkaline, pH, Equilibrium, Corrosion
Divisions
sch_civ,BuiltEnvironment,Architecture
Publication Title
Construction and Building Materials
Volume
411
Publisher
Elsevier
Publisher Location
125 London Wall, London, ENGLAND