Thermal Resistivity Testing for Flowable Fill, CLSM & FTB

Soil Tests Laboratory provides thermal testing services for flowable fill and thermal slurry mixes used around underground cables and duct banks. For FTB thermal resistivity testing, CLSM thermal resistivity testing or flowable fill thermal conductivity testing, send the material description and project specification with your quote request.

Match the Test to Your Backfill Specification

Controlled low-strength material (CLSM), flowable fill, thermal slurry and fluidized thermal backfill (FTB) are related terms, but they do not establish an identical mix composition or thermal performance requirement. Tell us how the material is identified in your specification and which thermal property the project requires.

Thermal backfill qualification testing provides measured material properties for comparison with the specified criteria. Include the required test method, units, sample condition and acceptance limits. If the specification refers to ASTM D5334 or IEEE 442, send the relevant section so the laboratory can review the requested scope and its applicability to your material.

Thermal Resistivity, Conductivity and Dry-Out Curves

Thermal resistivity describes resistance to heat flow; thermal conductivity describes the ability to transfer heat. They are reciprocal properties when expressed in consistent units. Moisture condition affects the result, so comparisons should use the conditions required for the project.

A single-point measurement characterizes the sample at a specified condition. A dry-out curve shows how measured thermal resistivity changes as moisture content decreases. Discuss which approach your engineer or specification requires before ordering thermal slurry testing.

Comparing Trial Mixes and Production Samples

For supplier mix qualification, identify each trial mix and provide its intended use. Keep mix IDs and sample labels consistent with your submittal. When requesting testing for production verification, include the batch or collection information and the mix being checked. Test results support review of the sampled material; they do not by themselves establish every aspect of installed performance or guarantee project approval.

Sample Instructions and a Testing Quote

Before casting or shipping, contact the laboratory to confirm specimen size, sample quantity, curing, packaging and shipping instructions for your material. Include your project specification, number of mixes or samples, required test conditions and reporting deadline. We can then discuss the appropriate thermal testing scope and quote.

Request a Thermal Backfill Testing Quote

Related services: Thermal Resistivity and Conductivity Testing · Concrete Rho Testing for Ready-Mix Producers