Effect of filtering method on the pH measurement of cement mortar in ex-situ leaching
Document Type
Article
Publication Date
2-1-2024
Abstract
The high alkaline condition of concrete naturally protects embedded steel bars from corrosion by forming a passive protective film. The pH of concrete is generally high, but concrete with different mix compositions may have various pH values. The pH of concrete may decrease over time due to long-term mechanical, chemical, biological and physical factors. Therefore, monitoring the pH value of concrete is crucial to checking if its alkalinity is within an acceptable range and ensuring that the concrete structure is in good health condition. However, the pH measurement for cementbased materials is not standardised. Ex-situ leaching, one of the recommended methods for pH measurement, is simple and practical. In this method, the sample will be crushed, leached and tested using a pH electrode probe. The lifespan of the pH electrode probe may decrease due to the existing suspended particles in the solution. Therefore, one recommendation is to filter the solution before using the probe. In this study, the effect of different filtering setups on the pH value of a cement mortar with a cement-to-sand ratio of 1:3 was evaluated. pH test results showed that filtering can produce similar outcomes to those without filtering, regardless of the type of filter paper and its pore size. However, filtering is strongly recommended for electrode protection of the pH meter. As an innovative filtering setup for cement-based materials, syringe filtering was introduced in this study because it is more economical and its operation is simpler compared to the other methods.
Keywords
pH value, pH measurement, Ex -situ leaching, Filtering setup, Cement mortar, Syringe filtering
Divisions
sch_civ,BuiltEnvironment
Funders
Universiti Malaya research grant (MG002-2021),PKN Building Solutions Sdn,Bhd. through Universiti Malaya (PV023-2021)
Publication Title
Heliyon
Volume
10
Issue
4
Publisher
Elsevier
Publisher Location
50 HAMPSHIRE ST, FLOOR 5, CAMBRIDGE, MA 02139 USA