Silica Fume Testing
(Microsilica — IS 15388)

Complete physical and chemical testing of silica fume (microsilica) for use in high performance concrete as per IS 15388 — verifying SiO₂ content, fineness, activity index and bulk density.

Overview

What is the Silica Fume Testing?

Silica Fume (Microsilica) is an ultra-fine pozzolanic material — a by-product of silicon and ferrosilicon alloy production — consisting of spherical amorphous SiO₂ particles approximately 100× finer than cement. It dramatically enhances concrete strength, reduces permeability and improves durability when used at 5–10% cement replacement.

At Global Lab, silica fume testing is conducted as per IS 15388 covering SiO₂ content (≥85%), fineness (BET surface area), bulk density, moisture content, accelerated pozzolanic activity index and chemical analysis. These parameters directly govern silica fume's contribution to concrete strength and durability.

SiO₂ Content Verification

Minimum 85% SiO₂ per IS 15388 — primary pozzolanic reactivity indicator.

Pozzolanic Activity Index

28-day mortar strength with silica fume vs OPC control.

BET Surface Area

Ultra-high fineness confirmed by BET nitrogen adsorption method.

Chemical Analysis

SiO₂, Al₂O₃, Fe₂O₃, CaO, MgO, SO₃, Na₂O+K₂O quantified.

NABL Certified Reports

All results on NABL-accredited letterhead per IS 15388.

Batch Quality Control

Batch-to-batch consistency monitoring for HPC project use.

Test in Action

Silica Fume Testing — Site Images

Silica Fume Sample Preparation

Pozzolanic Activity Mortar Cubes

Chemical Analysis by XRF Method

Test Procedure

How the Silica Fume Testing is Conducted

1

Sample Collection

Silica fume sample collected from bag, bulk bag or silo per IS 15388 sampling procedure.
2

Physical Tests

Bulk density, moisture content, fineness (BET and 45μm sieve residue) per IS 15388.
3

Pozzolanic Activity Index

Mortar cubes with 10% SF + 90% OPC vs 100% OPC control. 28-day strength activity index.
4

Chemical Analysis

XRF or classical chemical analysis for SiO₂, Al₂O₃, Fe₂O₃, CaO, SO₃, alkalis and loss on ignition.
5

IS 15388 Compliance Report

All results vs IS 15388 requirements. NABL report issued within 35 days.

Standards & Specifications

Applicable Test Standards

Standard	Title	Scope	Type
IS 15388	Silica Fume — Specification	Silica Fume Standard	Indian Standard
ASTM C1240	Standard Specification for Silica Fume Used in Cementitious Mixtures	Silica Fume	ASTM
BS EN 13263	Silica Fume for Concrete — Definitions, Requirements and Conformity Criteria	Silica Fume	British Standard
IS 1727	Methods of Test for Pozzolanic Materials	Pozzolan Testing	Indian Standard

Applications

Where is the CAPO Test Used?

Source approval and batch quality control of silica fume for HPC projects

Bridges, nuclear and marine structure HPC concrete silica fume verification

Ready mix concrete plant incoming silica fume acceptance testing

Research on silica fume quality from different production sources

High-rise building column HPC mix design silica fume characterisation

Precast concrete silica fume content and quality verification

Why Choose Global Lab

Our Advantages

NABL Accredited ReportsLegally valid IS 15388 compliance certificates for procurement and QC.

Chemical + Physical PackageBoth physical and chemical parameters in single comprehensive report.

HPC Mix Design IntegrationSilica fume test data directly used in our HPC mix design service.

Autovity Digital ReportsAccess silica fume test data digitally from any device.

Multiple Source ComparisonComparative testing of silica fume from multiple producers.

Batch MonitoringRegular batch quality monitoring for long-running HPC projects.

Silica Fume Testing(Microsilica — IS 15388)