Identify Subgrade Voids

 

The Slab Impulse Response (SIR) method is used primarily to identify and map subgrade voids below slabs-on-grade, although it also sees use in general condition evaluation of structural elements. This method is excellent for evaluating the repair of slab subgrade support conditions by comparing the support conditions before and after repairs. The SIR method is often used in conjunction with Ground Penetrating Radar for subgrade void detection and mapping.

The SIR method has been used on slabs of a wide range of thicknesses, but is most effective on thinner slabs (less than 12 inches thick). The method is generally limited to slab thicknesses of less than about 20-24 inches in thickness for most applications.

An alternate application of the SIR method is in the general evaluation of the condition of concrete structures. In this application, the method is used to look for low-stiffness areas associated with hidden damage such as honeycomb, void, and cracking. The method can be used for a fast evaluation of structural conditions, with a more detailed investigation than performed with Impact Echo or Ground Penetrating Radar.

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