Scribd
Upload
686 views2 pages

Reactive Silica Content

The document discusses the measurement of reactive silica content in supplementary cementitious materials (SCMs) such as fly ash. Reactive silica is defined as the fraction of total silica (SiO2) that is soluble after treatment with hydrochloric acid and boiling potassium hydroxide solutions. The measurement procedure involves treating a sample with these solutions, measuring the insoluble residue, and calculating the reactive silica content by subtracting the silica contained in the insoluble residue from the total silica content. The protocol is based on the European standard test methods for cement described in EN 196-2.

Uploaded by

Yuvaraj Dhandapani
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
686 views2 pages

Reactive Silica Content

The document discusses the measurement of reactive silica content in supplementary cementitious materials (SCMs) such as fly ash. Reactive silica is defined as the fraction of total silica (SiO2) that is soluble after treatment with hydrochloric acid and boiling potassium hydroxide solutions. The measurement procedure involves treating a sample with these solutions, measuring the insoluble residue, and calculating the reactive silica content by subtracting the silica contained in the insoluble residue from the total silica content. The protocol is based on the European standard test methods for cement described in EN 196-2.

Uploaded by

Yuvaraj Dhandapani
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 2

Reactive silica determination of SCMs

Measurement principle
The measurement of reactive silica is a commonly used method to estimate the reactivity of the
SCM. The reactive silica content is defined according the EN 197-1 as that fraction of the SiO2,
which is soluble after treatment with hydrochloric acid (HCl-solution) and with boiling potassium
hydroxide solution (KOH-solution). The quantity of reactive silica is determined by subtracting from
the total silica content that fraction contained in the insoluble residues. Both on a dry basis. The
measurement methods are based on the European standard for testing of cement EN 196-2 .

Protocol
An overview of the procedure is shown in Figure 1. Detailed accounts on equipment and reagents
can be found in the respective sections of EN 196-2 (copy of which can be found on the dropbox).
Please take note of the following:

For the calculation the amount of the insoluble residue (IR) needs to be considered
according to EN 196-2. The amount of silica is analysed on the extracted residue after
drying and ignition at 950 C and cooling down in a desiccator. Usually the determination
of SiO2 is carried out on a fused bead against accepted standards.

The reactive silica part is calculated as follows:

2 = 2 (2 (
))
100

Figure 1. Overview of the method to determine reactive silica of an SCM (in the example of fly ash
(FA)) based on EN 196 -2 and ECOBA test procedures.

You might also like