AMRL Accredited Laboratory
The Pavement/Materials Laboratory at UNR is fully accredited and certified by the AASHTO Materials Reference Laboratory (AMRL). The laboratory is equipped with over $600,000 worth of laboratory instruments to test the strength and weaknesses of asphalt pavements. The equipments currently available can be divided into 3 general areas:
- Asphalt binders testing equipments,
- Asphalt mixtures testing equipments, and
- Aggregate/soil preparation and testing equipments.
1. Asphalt binders testing equipments
The current capabilities of the pavements/materials laboratory allow for the characterization of asphalt binders using state of the art testing equipments. Using fundamental engineering parameters, the physical properties of asphalt binders are measured for performance characterization.
The current capabilities in the area of asphalt binders testing spans over two groups of testing procedures and equipment: 1) traditional asphalt binders testing and 2) Superpave asphalt binders testing (Table 1 below).
Table 1: Asphalt binders tests
Traditional testing area
- Ductility of bituminous materials.
- Thin-film oven test.
- Rolling thin-film oven test.
- Kinematic and absolute viscosity of asphalts.
- Penetration of bituminous materials.
- Specific gravity and density of asphalts.
- Flash point of asphalts.
- Softening point of asphalts.
Superpave asphalt binders testing area
- Dynamic Mechanical Analysis of Asphalt Binders using DSR.
- Bending Beam Rheometer.
- Pressure Aging of Asphalt Cement.
- Direct Tension of Asphalt Binder.
- Visocity Determination of unfilled asphalt using Brookfield Thermosal Apparatus.
Rolling thin-film oven (RTFO) Test – Simulates the short-term aging of asphalt binders that occurs during the hot-mixing process.
Asphalt binder samples are exposed to heat as they are rolled inside their jars.
Pressure Aging Vessel (PAV) Test – Simulates the long-term aging of asphalt binders that occurs during the pavement in-service life.
Asphalt binder is exposed to heat and pressure to simulate in-service aging over a 7 to 10 year period.
PAV pan (with a quarter for scale).
Dynamic Shear Rheometer (DSR) Test – Used for testing viscosities of asphalt binders at medium to high temperatures by determining the complex shear modulus of a sample twisted between two parallel plates.
Bending Beam Rheometer (BBR) Test – Used to test asphalt binders properties at low temperatures where the main failure mechanism is thermal cracking.
Simply supported asphalt beam subjected to a small load over 240 sec. Beam stiffness and rate of change of that stiffness as the load was applied are calculated.
Similar to the asphalt binder case, the current capabilities of the pavements/materials laboratory allow for the characterization of asphalt mixtures using state of the art testing equipments. The physical and mechanical properties of asphalt mixtures are measured for performance characterization. The current capabilities span over the traditional and Superpave asphalt mixtures testing areas (Table 2 below).
Table 2: Asphalt mixtures tests
Traditional testing area
- Bulk specific gravity and density of asphalt mixtures.
- Effect of moisture on asphalt mixtures.
- Indirect tension test for resilient modulus and tensile strength.
- Compaction by the kneading compactor.
- Hveem mix design for asphalt mixtures.
- Marshall mix design for asphalt mixtures.
- Theoretical maximum specific gravity of asphalt mixtures.
- Static creep testing.
- Extraction of aggregates using the ignition oven.
- Extraction of aggregates using the centrifuge method.
- Extraction of aggregates using the reflux method.
- Recovery of asphalt binder using the Rota-vap method.
- Recovery of asphalt binder using the Abson method.
- Compaction by the Superpave Gyratory compactor.
- Determining the rutting resistance of compacted bituminous mixtures subjected to repeated biaxial loading using the Superpave Shear Tester (SST).
- Determining the rutting resistance of compacted bituminous mixtures subjected to repeated load triaxial testing (RLT).
- Measuring the dynamic modulus master curve.
- Determining the fatigue life of compacted bituminous mixtures subjected to repeated flexural bending.
- Determining the fracture strength and fracture temperature of compacted bituminous mixtures subjected to cold temperatures.
- Indirect tensile creep modulus testing of asphalt mixtures.
- Short-term aging of asphalt mixtures,
- Long-term aging of asphalt mixtures.
- Creep testing of asphalt pavement cores and laboratory specimens.
- Environmental Conditioning System.
Superpave Gyratory Compactor (SGC) – Used to compact asphalt mixtures’ samples to a density similar to that obtained in the field under traffic.
The required number of gyrations is based on environmental conditions and traffic levels expected at the job site.
Asphalt Mixture Performance Test (AMPT) – Measure the dynamic modulus of asphalt mixtures for mix design and structural design.
The modulus properties of asphalt mixtures are function of temperature, rate of loading, age, and mixture characteristics.
Repeated Load Triaxial (RLT) Test – Measure the resistance of asphalt mixtures to permanent deformation at high temperatures
The cumulative axial permanent deformation of the specimen is measured under a repeated haversine vertical load and a constant confining pressure. The testing conditions are to simulate the performance of asphalt mixtures under moving truck loads.
Left: Asphalt mixture specimen before and after testing.
Thermal Stress Restrained Specimen (TSRST) Test – Simulates field conditions to estimate the low temperature properties of the asphalt mixtures.
Tensile stresses are generated in the beam by cooling down the specimen at a rate of 10°C/hr while restraining it from contracting. The temperature at which the beam fractures is referred to as “fracture temperature” and represents the field temperature under which the pavement will experience thermal cracking.
3. Aggregate/soil preparation and testing equipments.
The pavement/materials program has an extensive inventory of aggregate preparation and testing equipment and facilities. Approximately 1000 square feet of existing laboratory space is devoted to aggregate/soil preparation, testing and batching. Four sizes of splitters are on hand for obtaining representative samples of stockpiled materials. After being split, the material is processed as is or is run through one of three types of aggregate crushers. A large, floor-mounted Gilson shaker aids in large volume aggregate sieving while two conventional Ro-tap shakers are used for actual sieve analyses. The program is capable of performing the following tests:
- Aggregate durability index.
- Centrifuge kerosene equivalent.
- Clay lumps and friable particles in aggregates.
- Flat and elongated particles in coarse aggregates.
- Freeze and thaw resistance of aggregates.
- Sand equivalent test.
- L.A. abrasion test.
- Soundness of aggregate.
- Specific gravities and absorption of aggregates.
- Unit weight and voids in aggregates.
- Resilient modulus test for unbound materials.
Facilities, Equipment, and Other Resources
The Environmental Engineering Laboratories of the Civil and Environmental Engineering Department at the University of Nevada, Reno include approximately 5,000 square feet of floor space. Instrumentation available for all standard water quality analyses includes:
- Atomic adsorption spectrophotometer – Perkin Elmer, Model 3030
- Epifluorescent microscope – Nikon Model Eclipse E-400 with SPOT image analysis
- Flow Injection Analyzer – Lachat, Model Quik Chem 8500
- Gas chromatographs – Hewlett Packard, Model 5980 and Model 6890
- Gas chromatograph/mass spectrometer – Hewlett-Packard, Model 5890/5971
- High performance liquid chromatograph – Hewlett-Packard, Model 1050
- Inductively coupled plasma spectrophotometer – Perkin Elmer, Model Optima 2100DV
- Ion chromatograph – Dionex, Models ICS 2000 and DX-300
- Jar testing apparatuses: Phipps & Bird, 2 - model PB 700
- Multi parameter portable instruments - YSI 556
- Particle counter – Coulter, Multisizer IIe Model
- Particle size distribution analyzer – Coulter, Model LS 230
- Portable spectrophotometers - HACH DR 2500,
- Scintillation counter – Beckman, Model LS 5000 CE
- Total organic carbon analyzer (Combustion) – Shimadzu TOC-VCSH
- Total organic carbon analyzer (Persulfate Oxidation) Tekmar Dohrmann, Phoenix 8000
- Turbidimeters - bench top HACH 2100, portable HACH Model 2100P,
- UV/Vis spectrophotometer – Varian, Model CARY 300 Bio
- Ultrapure water systems - Millipore Direct Q/ RiOs 16 and Elix 3
Major instruments for membrane surface and performance characterization that are located in the Environmental Engineering Laboratories include:
- 3 submerged membrane bioreactors test units
- 4 bench-scale membrane test units:
- Pressure filtration unit with stirred cell and pressure vessels from Sterlitech
Fully automated crossflow system, SEPA CF from Osmonics
Partially automated forward osmosis system
Partially automated membrane distillation system
- 3 pilot-scale membrane test units
- Forward osmosis system
Pilot-scale low pressure RO/NF system 1-1-1 (3 elements) 4040 up to 300 psi from Osmonics
Pilot-scale UF automated system with automatic backwashing
- Pilot-scale solar pond/membrane distillation system
- Contact angle goniometer – Rame Hart, Model 100-00-(115)-S
Electrophoretic mobility analyzer – Zeta-Meter, Model 3.0+
Streaming potential analyzer – CAD Instrumentation, ZetaCAD Model
The Structural Engineering Program has two laboratories for the conduct of research and to support graduate classes in earthquake engineering. The largest of these is the high-bay laboratory in the Harry Reid Engineering Laboratory, with 8,400 sq. ft. of strong floor and a 20 ft reaction wall. It is known as the James E. Rogers and Louis Wiener Large-Scale Structures Laboratory. This lab is equipped with state-of-the-art servo-hydraulic equipment for the application of dynamic loads to large-scale structures, and in particular the simulation of earthquake loads.
The laboratory received the ‘2007 Best Experimental Site Innovation’ Award from the NEES Consortium in recognition of its expertise and innovation in experimental simulation.
Principal items of equipment include:
- Three biaxial shake tables. Each table is 14 ft square and has a payload capacity at 1g acceleration of 50 tons. Maximum displacement is +12 ins in both x- and y-directions, and maximum velocity is 40 ins/sec.
- One 6-dof shake table, 8 ft square with payload capacity at 1 g acceleration of 20 tons. Maximum displacement is + 12 ins, + 3 ins, and + 4 ins in the x-, y-, and z-directions respectively. Maximum velocity is 60, 35, and 55 in/sec in the x-, y-, and z-directions respectively.
- All four tables are relocatable on a tie-down strong floor and may be operated (1) as a single large table with identical input motions, (2) individually with independent input motions; or (3) as a set of tables with asynchronous input motions.
- Five hydraulic pumps with continuous total flow rate of 610 gpm at 3,000 psi. Three blow-down accumulators are used to achieve performance values noted above.
- One, 220 K, MTS load-frame with hydraulic grips
- 400 channels of high speed data acquisition.
- 17 servo-controlled actuators ranging in capacity from 35 to 700 K.
- Servers (many) including an SGI Origin 2200 and a 1 Tb Dell Data Server.
The second laboratory is a teaching and research laboratory for use by undergraduate and graduate students in structural dynamics. Currently under renovation, this laboratory is being remodeled as an interactive classroom. Two instructional shake tables (one by Quanser and one by MTS) are available for use in this lab.
The College of Engineering has a 5,000-square-foot computing facility with 100 computers including Windows and Linux. Additionally, numerous computers are available in the Environmental Engineering Laboratories.