Joshua Midence (Civil Engineering)

Joshua Midence (Civil Engineering)

About DOE Fellow
Mr. Joshua E. Midence was inducted into the DOE Fellowship in 2011. He is currently pursuing a bachelor’s degree in civil engineering with a specialization in transportation engineering. Joshua was inducted into Delta Epsilon Iota academic honor society in the Fall of 2011. Joshua has also been selected as one of 25 out of 148 applicants for the prestigious Ronald E. McNair Post Baccalaureate Achievement Program as part of the 9th cohort, which provides the support and foundation for entering a master’s degree program. Joshua has been inducted into Chi Epsilon which is the National Civil Engineering Honor Society in April of 2013. Mr. Midence was chosen to serve at the pleasure of Mayor Carlos Gimenez in the Miami-Dade County Mayor’s Executive Internship Program to try to revitalize the Rickenbacker Causeway in Key Biscayne, Fl. under the strict supervision of Joan Shen, P.E., Ph.D., PTOE.

Josh’s Achievements/Honors include:

  • 1st Place in 2013 Material Advantage: Undergraduate Technical Poster Presentation
  • 1st Place in Oral Presentation for Ronald E. McNair Post Baccalaureate Achievement Program
  • 3rd Place in ASCE Southeastern Conference 2013: Steel Bridge Deflection/Stiffness Test
  • Miami-Dade College: General Construction Estimation Certification

Josh’s Academic Projects and Seminars include:

  • ASCE Southeastern Student Conference 2013: Concrete Canoe/Steel Bridge building Contest
  • Waste Management Symposium 2012 & 2013
  • Engineers Without Borders: Southeast Regional Fall Conference 2012
  • Miami-Dade County Leadership Training Certificate 2013

Josh’s Professional Affiliations include:

  • Student Member: American Society of Civil Engineers (ASCE)
  • Student Member: Society for Hispanic Professional Engineers (SHPE)
  • Student Member: Conference of Minority Transportation Officials (COMTO)

After completing his bachelor’s degree, he plans to pursue a master’s degree in structural engineering. His interests include dancing, golf, drawing, school, and any form of free expression. Joshua is being considered for “FlipSideKings” (FSK) Miami, Fl. Joshua is a member of the “Team 305” golf team in Miami, Fl.


Savannah River National Laboratory (SRNL)
Mentor: Alex Cozzi, Ph.D.

“Saltstone Processing of Low-Level Waste at Savannah River Site”

A brief Introduction and Background:

The Saltstone Production Facility (SPF) at the Savannah River Site in Aiken, South Carolina receives low level waste (LLW) salt solution from Tank 50H for treatment and disposal. Tank 50H receives transfers from the Effluent Treatment Project (ETP), the H-Canyon General Purpose Evaporator, and the Actinide Removal Process/Modular Caustic Side Solvent Extraction Unit (ARP/MCU) Decontaminated Salt Solution Hold Tank (DSS-HT). At the Saltstone Production Facility, the low level waste is mixed with a premix [a cementitious mixture of portland cement (PC), blast furnace slag (BFS) and Class F fly ash (FA)] in a Readco mixer to produce fresh (uncured) Saltstone that is transferred to the Saltstone Disposal Facility (SDF).

The Saltstone formulation (mix design) must produce a grout waste form that meets both placement and performance properties. In previous simulated Saltstone studies, multiple compositional factors were identified that drive the performance properties of Saltstone made from the projected ARP/MCU salt solution.

Experimental Approach:

Performance testing of the Saltstone will be conducted in order to determine the best mixture of premix/cementitious mixture for filling tanks that need to be closed. Some of the factors that need to be investigated include pH levels of surrounding groundwater (to determine the effect of the Saltstone mixture in the future), strength of the concrete, hydraulic conductivity, and porosity of the mixture (all of which are contributing factors to the overall performance of the Saltstone grout in the vaults).

Some of the experiments that will yield results as to the perfect premix ratio for the Saltstone that will be poured into the vaults include:

  • Leach Testing – Percolating samples for pH, conductivity and release of contaminants
  • Concrete Compression Testing – Strength of samples
  • Blaine Fineness Testing – Measures air permeability of dry cementitious materials
  • Hydraulic Conductivity Testing – Measures the capability of a medium to transmit water
  • Moisture Content Analysis – Performance for bulk drying

Dept. of Energy Related Projects:

Meso-Scale Testbed project:

Josh is currently working under the supervision of his mentor, Amer Awwad, M.S, P.E. He has also contributed to the Meso-scale testbed project on the day of the pour. The Meso-Scale Testbed project consists of a decommissioning process which involves filling all below grade areas with cementitious materials. This experiment is using various sensors including Electrical Resistivity Tomography, Advanced Tensiometers, Piezoelectric Sensors, and Fiber Optic Sensors (ERT, AT, PES, FOS) to measure various parameters including strain, crack detention, corrosion, fluid mobility, moisture, as well as other variables. This project was in coalition with Mississippi State University, University of South Carolina, University of Houston and Idaho National Laboratory.

Asynchronous Pulse Unit (APU) System Project:

Joshua has been working with the Asynchronous Pulse Unit system conducting research that involves programming experimental mathematical sequencing pressure pulses in simulation models that will provide successful solutions to dislodge plugs in nuclear waste pipelines. The FIU test loop used to test the asynchronous pulsing system contains two identical pipeline sections with a plug between them. This test loop allows control of the individual pipeline section pulse characteristics to determine how each pulse influences the total plug dynamic loading. The experimental loop was assembled using four straight sections and two 90o elbows. The pipes used for the loop are 3-inch in diameter schedule-10 carbon steel pipes. Each side of the symmetric loop has a 9-foot and an 8-foot pipe with an elbow between them. A blockage was placed at the center of the loop to emulate a plug in the pipeline. The pipeline is instrumented with accelerometers, pressure transducers and thermocouples located at strategic locations to capture the changes of the induced disturbances inside the pipeline. Also, the system’s ability to unplug the magnesium sulfate (k-mag) type plugs in a large scale pipeline will be investigated.
Joshua E. Midence assisted with the system component selection, system drawings and system fabrication and assembly. Joshua was responsible for testing the technology and collecting experimental data generated by the experimental set-up. Joshua had been tasked with data management and providing his support during data analysis and presentation of the Asynchronous Pulsing Unit.