The Slab Impulse Response (SIR) method is used primarily to identify and map subgrade voids below slabs-on-grade.

  • Fast, one-sided testing
  • Most effective on thinner slabs (less than 12 inches thick)
  • Limited to slab thicknesses of less than 20 to 24 inches

SIR can be used to:

  • Evaluate the support conditions before and after repairs of slab subgrade
  • Look for low-stiffness areas associated with hidden damage (honeycomb, void, or cracking) for general assessment of concrete structures
  • Subgrade void detection and mapping, in conjunction with Ground Penetrating Radar
Slab Impulse Response SIR, Olson Engineering

Applicable On:

Concrete Structures

Reinforced and Nonreinforced Concrete Slabs

Pavements

Runways

Spillways

Pond and Pool Bottoms

Tunnel Liners

Asphalt or Asphalt-Overlay Slabs

Test For:

Subgrade Void Detection

Evaluating Repair of Slab Subgrade Support up to 2 Feet Thick

Slab Impulse Response SIR, Olson Engineering
Slab Impulse Response SIR, Olson Engineering
Slab Impulse Response SIR, Olson Engineering

The SIR System

Diagnose Defects

Identify and map subgrade voids below slabs-on-grade

Evaluate

General condition evaluation of structural elements

Slab Impulse Response SIR, Olson Engineering
Comparison

Evaluate the repair of slab subgrade support conditions by comparing the support conditions before and after repairs

Variety of Applications

Test on concrete slabs, pavements, runways, spillways, pond and pool bottoms, and tunnel liners

Combine Methods

This method is often used in conjunction with GPR