A New Real-Time, Non-Contact Transfer-Length Measurement Technique Dr. Terry Beck (Mechanical Engineering) Dr. Robert Peterman (Civil Engineering) Dr. John Wu (Industrial Engineering) Weixin Zhao (Industrial Engineering) Inventors:Inventors:

What is the problem for which you have a solution ?

Why Measure Transfer Length? Used for calculation of shear capacity Used for calculation of stresses Has been shown to often be a good indicator of strand development length Could be used as a tool to screen out potentially poor-bonding mixes

How is the problem being solved now? What’s wrong with current solutions? We simply don’t measure it?

Why Don’t We Measure Transfer Length at the Present Time? There is currently not a convenient or time-efficient method to get this information The current method(s) interrupt the daily casting and de-tensioning sequence

Current Tool Whittemore Gauge

Strain in Pretensioned Concrete Member

What is our solution? Non-Contact Measurements Portable as Current Tool Much Higher Precision More Flexible

Concept of Laser Speckle

Photograph of Laser Speckle on Concrete

Peak Distances vs. Strains Measures 0.02mm deflection0.10mm deflection0.20mm deflection

Actual experimental work we have performed?

Concrete beam cutting experiment Prototype Design Experiment Setup Beam Cutting

Cutting Pretensioned Specimen

Comparison of Different Strain Gauges

Prototype Specification 4  1/4 inches 8 in Resolution: < 10  m Weight: 3 lbs Dimension: 11”x6”x4” Measurement speed: 15 samples/second Optical Sensor

Concrete Cylinder Compression Experiment Electronic Strain Gage Optical Strain Gage

Concrete Cylinder Results

What is the closest prior art that might be cited against the novelty of your invention? None !

What Still Needs to Be Done? Continue to Gather SCC Mix Ingredients Cast Pretensioned Transfer-Length Specimens Members from 5 mixes used in SCC bond study Compare Whittemore Gage Results with Optical Results

Additional K-State Personnel Have Been Added Commercialization Manager. 2 MBA Students (Final Project). Product Design Engineer. 2 Other Design Engineers (Optics and Electrical). Precision Optical Measurements, Inc.

The Goal Version 1 available for use this summer. For sale within one year (Approx. $20k)

The Future

Measurement Surface Traverse Sensor Auto Measuring System

Delta Strain Rosette

Who specifically would be a possible commercial partner or licensee for your invention? Precision Optical Measurement Inc. Advanced Manufacturing Institute

Questions?