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Technical Service Center
Materials Engineering and Research Lab

MERL Facilities

The Materials Engineering and Research Laboratory occupies the south 3½ acres of the U.S. Bureau of Reclamation's research facility, Building 56 on the Denver Federal Center. MERL has the facilities to test concrete, concrete reinforcement, selected metals testing, plastics, geotextiles, selected miscellaneous materials, and coatings.

Other research facilities collocated with MERL include: The Materials Engineering and Research Facility includes the following areas:

Room 1675 (2800 ft2)

Triaxial Testing Area. Triaxial testing machine - This testing machine is capable of determining shearing resistance of high strength cylindrical specimens up to 6-in. in diameter by 12-in. long. Specimens can be tested under a total axial load up to 7.5 million pounds, and a maximum confining pressure of 125,000 lb/in2.

Wire Torsion Test - Torsion tests of prestressing wire ranging is size from 0.162- to 0.3125-inch diameter can be performed with this machine. Torsional loading capacity ranges from 0- to 1500-in/lbs. Torsion can be applied in either a clockwise or counterclockwise direction and can be reversed during a test. Rotating speed is infinitely variable, ranging from 0 to 30 revolutions per minute.

Space is also available for storage.

Room 1700 (4800 ft2) Large Frame Test Machine Area
The 4-million pound capacity hydraulic compression testing machine is capable of testing structural components, models, and specimens up to 6 ft. high, 4 ft.in length and 4 ft. wide. Large concrete cores and cylinders are regularly tested in this machine.
The 5-million-pound testing machine

The 5-million pound capacity hydraulic universal testing machine is capable of testing specimens up to 10 ft. wide, 40 ft. tall, and 32 ft. long. It is one of two such machines in the world. The test machine is capable of testing specimens in compression or tension, and is used to test large and high strength concrete cylinders, structural components, and many different metal configurations. (See video of the testing machine in action.)

Two other smaller machines are available for testing smaller specimens. They are the 400,000 pound capacity universal testing machine and the 100,000 pound capacity universal testing machine. Both are regularly used to test concrete, steel rebar, wire, cable, and many other materials. These machines are equipped with electronic servo controls capable of stress or strain controlled loading in either compression or tension.

There is a 15-ton capacity overhead crane in the area to move large, heavy test specimens around the room.

400,000 Pound Machine

100,000 Pound Machine

  Dynamic Testing Laboratory--The Dynamic Testing Laboratory features a 1 million pound capacity dynamic testing machine. It is generally used to test concrete core in dynamic compression and dynamic split tension at strain rates of ~0.001 microstrains per second. It can handle specimens 21 inches tall, 24 inches wide, and 24 inches deep.
Room 1705 (2700 ft2)

Sulfate Resistance of Concrete Testing Area--Three laboratory tests to determine the sulfate attack resistance of concrete, a major problem in the arid and semi-arid regions of the west, can be performed in this facility. The tests are: (1) accelerated test, which consists of alternately drying and soaking test specimens in a 2.1 % sodium sulfate solution; (2) high concentration continuous soak test, where specimens are continuously soaked in a 10% sodium sulfate solution; and (3) standard continuous soak test involving long term continuous soaking in a 2.1% sodium sulfate solution.

Abrasion erosion resistance testing is also performed in this area. Concrete specimens 12-inches in diameter and 3-inches thick are placed in the test apparatus, and a high speed mixer agitates steel balls which abrade the concrete surface. Weight loss is determined over a period of three days to assess the abrasion erosion resistance of differentconcretes

Room 1730 Freezing / Thawing Testing Facility

Aggregates proposed for use in concrete mixtures are evaluated for quality. They need to be hard, dense,durable, well graded, and chemically and physically sound. Physical properties tests for specific gravity, absorption, organic impurities, silt content, clay lumps, soundness, abrasion resistance, freeze-thaw durability, and other tests are performed in this laboratory.

Immediately adjacent to this lab is the concrete specimen capping facility. This equipment is used to place capping compound on the ends of concrete test specimens, so thatthe ends meet standards for planeness.

The laboratory is temperature and humidity controlled.

Room 1730 (1500 ft2) Aggregate and Riprap Testing Laboratory
Room 1732 (800 ft2) Concrete Core Layout Area--This room is temperature controlled for core layout and test specimen examination, selection, and preparation. There is an overhead crane to move large specimens. The room has perimeter floor drains so cores can be soaked andsprayed as appropriate.
Room 1740 (750 ft2) Specimen Preparation Area--A large scale 36-inch lapping machine is used to grind the ends of tests specimens flat to .002 in. to meet requirements of test standards. Specimens as large as 24 in. in diameter can be lapped on this machine. A 25-horsepower, 36-in. diameter diamond saw is used to cut rock and concrete specimens up to 14 in. thick. An 18-in.diameter diamond saw is used to cut rock and concrete specimens up to 8-in. thick.

Several portable drills are also available to take coresamples out of concrete and rock specimens.

Vacuum saturation equipment is available to quicklysaturate test specimens, if time constraints dictate.

Room 1746 (1200 ft2) Forklift corral--Charging stations are available for charging 4 forklifts, which are regularly used to move test specimens.
Room 1810 (900 ft2) Electronics Laboratory--This facility is used for assembling instrumentation systems for laboratory and field testing. A wide variety of instrumentation equipment is available for measuring tests parameters including strain, displacement, velocity, acceleration, pressure, load, temperature and humidity. In addition, dedicated acoustic emission and modal analysis systems are available.

Several computer controlled data acquisition systems as well as analog instrumentation recorders are used for recording test data. These systems can accommodate up to 80 data channels and data acquisition rates to 500,000 samples per second.
Room 1825 (2000 ft2) Walk-in Environmental Testing Chambers--Six free-standing, self-contained walk-in environmental chambers are available for testing programs that require precision temperature and humidity control. Three rooms, each measuring 10 by 10 by 8 ft., can be used to measure heat of hydration of mass concrete test specimens as they cure. They have a temperature range of 40° to 180° ±0.2°F. Another room, specially designed for cold tests, measures 10 by 10 by 8 ft. and has a range of –10° to 140° ± 3.0°F. The largest room, at 15 by 18 by 8 ft., is designed for high temperature tests and has a temperature range between 40° and 180° ±3.0°F, and can control humidity between 20% and 95% RH ± 5%. Also available is a cold storage room, measuring 10 by 10 by 8 ft. with a temperature range from 0° to 30° ±3.0°F.
Room 1829 (400 ft2) This facility houses equipment used to attach electronic strain measurement devices to test specimens. A wide variety of materials are regularly instrumented this way and tested to determine the material's stress-strain characteristics.

In addition, nondestructive testing equipment is available to evaluate concrete quality using sonic and ultrasonic techniques.

  Instrumentation Laboratory

Instrumentation laboratory

Room 1830 (500 ft2) Cement and Pozzolan Testing Laboratory--The physical and chemical quality requirements for cement and pozzolan are set by ASTM for Bureau work. Equipment for performing density, fineness, expansion, compressive strength, drying shrinkage, soundness, reactivity with alkalies, loss on ignition, and other tests is available in this facility to determine if these materials meet required standards. The lab is temperature and humidity controlled.
Room 1831 (500 ft2) Thermal Properties Laboratory--Specific heat, diffusivity, and coefficient of thermal expansion are determined using equipment in this lab. The test equipment used to measure values for these properties was developed and custom built in the lab. Specific heat is measured using 8-in. by 16-in. concrete cylinders with a 1½-in. hole through the longitudinal axis. The lab also has equipment to measure diffusivity and coefficient of thermal expansion on different sizes and shapes of specimens. Thermal conductivity is calculated using the measured specific heat and diffusivity values.
Room 1835 (1500 ft2) 50-Percent Relative Humidity Room--This room is maintained at 50 percent RH and 73°F. These are standard laboratory conditions for some tests. The room is used to cure concrete specimens and for specialized testing that requires a controlled environment.

Concrete creep testing, to determine concrete deformation that occurs under constant load, is performed in this facility. Loads can be automatically maintained through hydraulic oil pumps connected to an electronic pressure controller. Strain measurements can be taken manually or automatically using special strain gauges.

Drying shrinkage tests, and other length change tests can also be performed in this room as well.
The 50-percent relative humidity room

Room 1845 (2000 ft2) 100-Percent Relative Humidity Room (Fog Room)--This room is maintained at 100% RH and 73°F, which are the standard laboratory conditions for curing concrete test specimens. The room is designed to keep concrete specimens saturated.

Inside the "fog room"
Touring the Fog Room on Bring Your Child to Work Day (Photo by Bill White)
Room 1850 (5500 ft2) Aggregate Processing Area--This area contains equipment to process and prepare laboratory samples of concrete aggregates or riprap that may be used in Reclamation projects. Material is prepared for suitability testing, and can be processed, cleaned, sized, and aggregates can be manufactured to meet specific requirements.

Large samples are dumped on a "grizzly", which retains 3-inch size material. Material that is retained is manually classified. Aggregate that passes through the grizzly is conveyed by traveling belt to the Denver Dillon Screening plant. The 4-deck vibrating screening plant can wash and separate coarse aggregate into 4 sizes. Sand sizes are screened into a screw classifier, where the sand is washed again, and then removed.

Smaller aggregate samples can be processed with several pieces of equipment available in this area, such as the Ro-Tap, Tylab, Gilson, or "riddle" screens.

A gas-fired rotary dryer is available to dry large sand samples. After the sand is dried, it can be processed into separate sizes, using any of three vibrating sand screening plants.

Several pieces of equipment are available to manufacture aggregates. Two jaw crushers (12-inch and 6-inch) are used to crush large rocks. Cone crushers, a hammer mill, a rod mill, a sand roll, and other equipment are available to crush and size coarse aggregate and to manufacture sand.

The Los Angeles abrasion test is performed in this area, and provides information on the hardness and toughness of the coarse aggregate.

Several sand and aggregate bins are available for storing large aggregate samples.
The aggregate processing area

Room 1855 (2700 ft2) Concrete Mix Laboratory--This room houses equipment used to perform concrete mixture proportioning studies. Proportioning studies are conducted to optimize the proportions of cement, gravel, sand, water, and admixtures. Since different ingredients change concrete's properties, it is important to test concrete made from proposed source materials to gather information about the concrete's fresh and hardened properties. This facility is typically used to determine optimum mixture proportions for specialty concretes, such as mass concrete, roller compacted concrete, underwater concrete, and high performance concrete.

Equipment available for conducting mixture studies includes a 21 ft3 automated mixer, a 9 ft3 manually operated mixer, and several different types of smaller mixers. The mix room is temperature and humidity controlled.

Storage space is available for aggregates, cement and pozzolan, and admixtures.
The concrete mix laboratory

Room 1890 (800 ft2) Concrete Repair, Grout, and Polymer Concrete Laboratory--This facility houses a wide variety of equipment that is used to evaluate concrete repair materials, concrete-polymer materials, and cement and chemical grout materials. The lab is equipped with special mixers for studies of concrete repair and concrete-polymer materials and several types of grout pumps, for studies of grouting materials and for use in actual grouting applications.

Equipment is available to perform quality evaluations on proposed concrete repair materials, including tests on shrinkage, compressive strength, and durability. Tests on quality control of polymers and monomer safety, including tests on inhibitor concentration, catalyst requirements, and polymerization characteristics can be performed using equipment in the lab. The lab also contains equipment for grout studies, including studies of different grout formulations, their application to repair and construction issues, and developing procedures for their use.

Concrete Repair, Grout, and Polymer Concrete Laboratory

Room 1893 (2150 ft2)

Vibration Test Laboratory-- Structural components, models, and specimens may be tested dynamically in a variety of modes including tension, compression, fatigue, and vibration. Vibration testing capabilities range to 50,000 pounds force at frequencies up to 400-Hz and displacements ranging to 12 inches. Specimen sizes may range upwards to approximately 20 feet long by 15 feet wide and 20 feet high. Specimen weights up to 50,000 pounds may be accommodated.

The "shake table" in the vibration test laboratory

Room 2690 (2,000 ft2) Paints and Coatings Laboratory--A complete protective coatings and paint testing laboratory is available. The lab is capable of creating test specimens, including surface preparation and surface inspection. A wide variety of equipment is available for application and curing of coating systems. We can determine the performance of test specimens subjected to industry standard and specialized tests. Physical properties tests can be preformed on uncured coating samples, normally cured coating samples, and coated specimens that have been subjected to different accelerated weathering procedures.

The uncured properties can be examined by using a digital viscometer, with eight speeds, a choice of seven spindles, in a controlled water bath.

The cavitation resistance properties of coating systems can be tested in a venturi type cavitation testing machine.

Room 1330 (2400 ft2) Plastics Laboratory--This laboratory is maintained at a constant 50% RH and 73F (standard laboratory conditions for plastics testing). Sample preparation equipment includes a 50,000-lb capacity thermal-compression molder for preparing standard test pads, and several hydraulic presses for die-cutting test specimens.

The Instron 5,000-lb capacity universal test machine is computer controlled for automated testing, analysis, and data storage. Testing modules include an extensometer, and cyclical testing capability.

Three 2-ft diameter pressure vessels are used to test geomembranes over a variety of soil and man-made substrates. These pressure vessels are computer-controlled for automated testing and failure detection, allowing round-the-clock test programs.

Note: All rooms have forklift access. All labs are equipped with exhaust fans, hoods, emergency showers, eye wash stations, fire proof storage cabinets, and other safety equipment as appropriate.

Shop facilities are also available to make custom test fixtures, prototype models, and test equipment.