Rafael Diaz
Weslaco,Texas
Summary
Construction Materials Testing (CMT) Technician with strong hands-on experience in field and laboratory geotechnical services. Proficient in in-situ density testing, nuclear gauge operation, and concrete field testing per ASTM/AASHTO standards. Skilled in soil classification (USCS/AASHTO), sample logging, and supporting engineering teams with high-accuracy results. Bilingual and safety-driven with a solid record of reliability and field compliance.
Overview
9
9
years of professional experience
1
1
Certification
Work History
Construction Materials Technician
Tolunay-Wong Engineers
05.2024 - Current
- Perform in-situ field density testing of soils and base using nuclear gauge in accordance with ASTM D6938.
- Conduct concrete field tests (ASTM C143, C231, C138) for slump, air content, temperature, and unit weight.
- Sample and log soils for classification (USCS/AASHTO) and assist with moisture-density relationship (Proctor) lab testing.
- Coordinate with project engineers and contractors to ensure testing meets specifications.
- Maintain and calibrate testing equipment; document and submit field reports daily.
- Follow strict safety and quality assurance protocols on construction sites.
Warehouse Lead
ProPetro Services
07.2022 - 02.2024
- Oversaw warehouse operations for oilfield service logistics; ensured safe storage and deployment of high-value equipment.
- Tracked inventory for field support; implemented safety checks and Lean process improvements.
- Coordinated shipment and return of materials between work crews and vendors.
Cable Technician
TelePro, Inc
03.2019 - 10.2020
- Installed, tested, and maintained coaxial/fiber optic systems across residential and commercial sites.
- Performed site assessments and handled routing in confined or elevated spaces.
Assistant Store Manager
Stripes
08.2016 - 03.2019
- Managed store operations, inventory control, and staff scheduling in a high-volume setting.
- Trained new employees and implemented process improvements to increase sales and customer satisfaction.
Education
High School Diploma -
Progreso High School
Progreso, TX05.2014
Skills
- In-Situ Density & Moisture Testing (Nuclear Gauge – Troxler/Humboldt)
- Soil Classification (USCS & AASHTO Methods)
- Proctor Testing (Standard/Modified)
- Concrete Field Testing (Slump, Air Content, Temp, Cylinders)
- Asphalt Core Sampling & Extraction
- Aggregate Gradation & Sieve Analysis
- Construction Material Sampling (Soils, Concrete, Asphalt, Aggregates)
- Field/Lab Data Logging & Chain of Custody
- Microsoft Excel, Word, and Report Templates
- Fluent in English & Spanish
- OSHA 10-Hour Construction Safety
Certification
- APNGA Nuclear Density Gauge Safety & U.S. DOT Hazmat Certification
- OSHA 10-Hour Construction Safety Training
- Class C Driver’s License – Clean Record
Languages
English
Native or Bilingual
Spanish
Native or Bilingual
Timeline
Construction Materials Technician
Tolunay-Wong Engineers
05.2024 - Current
Warehouse Lead
ProPetro Services
07.2022 - 02.2024
Cable Technician
TelePro, Inc
03.2019 - 10.2020
Assistant Store Manager
Stripes
08.2016 - 03.2019
High School Diploma -
Progreso High School
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