U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000


Skip to content U.S. Department of Transportation/Federal Highway AdministrationU.S. Department of Transportation/Federal Highway Administration

Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

Overview | Projects

 

 

Concrete Laboratory

 

Purpose: Researchers in the Concrete Laboratory evaluate new test methods, conduct concrete materials research, develop mixture design and analysis procedures for concrete pavements, and provide concrete forensics.

Laboratory Description: The Concrete Laboratory has facilities for evaluating plastic and hardened concrete properties, including  rheology, setting, and calorimetry; concrete curing and volume change; concrete durability, including freezing,  and thawing, and alkali-silica reaction; and mechanical properties, including strength and modulus of elasticity.

Laboratory Capabilities: The laboratory batches, mixes, and conducts tests on cement paste, mortar, and concrete. A curing room is available for curing concrete specimens under standard or other controlled conditions, and for assessing curing-related properties, such as degree of hydration, maturity, and shrinkage. The Concrete Laboratory includes facilities for investigating the effects of chemical and environmental exposure on concrete, as well as capabilities for assessing a number of distress mechanisms, including alkali-aggregate reaction, sulfate attack, chloride penetration, freezing and thawing, and thermal effects. The Concrete Laboratory also has an aggregate materials and sample preparation room.

Facilities are available for testing the mechanical properties of concrete, steel, and composites. These facilities are inspected by the Cement and Concrete Reference Laboratory and accredited by the American Association of State Highway and Transportation Officials Materials Reference Laboratory.

Laboratory Equipment: Several concrete, mortar, and paste mixers of various sizes and types are available in the Concrete Laboratory, including a high-shear paste mixer and a high-intensity concrete mixer (Figure 1).

The image shows a high-intensity concrete mixer, which has a metal mixing unit attached to an arm that can be lowered into a metal bowl where the concrete is mixed.

Figure 1. High-Intensity Concrete Mixer.

Equipment for evaluating early-age mixtures includes a Vebe Consistometer, a Dynamic Shear Rheometer (Figure 2), a semi-adiabatic calorimeter, and an isothermal calorimeter (Figure 3).

The image shows a dynamic shear rheometer with parallel plates system.  The cement paste is sandwiched between the two parallel plates and then the shear stress and strain are measured as the upper plate is oscillated.

Figure 2. Dynamic Shear Rheometer.
  The image shows an isothermal calorimeter with sixteen channels and four glass ampoules.  Eight of the channels are used for the reference materials and the other eight are used for the materials under study.  Isothermal calorimeter is a versatile tool for monitoring the hydration of cementitious materials at the early age.

Figure 3. Isothermal Calorimeter.

Concrete curing equipment includes three controlled curing tanks and two walk-in environmental chambers. Equipment for evaluating the durability of concrete includes an automated freeze-thaw chamber (Figure 4) with the capacity for 17 specimens, coefficient of  thermal expansion test frames (developed in-house and obtained commercially), computer-controlled chloride penetration test equipment, and a surface resistivity apparatus (Figure 5).

This image shows a freeze-thaw chamber with sixteen 3-inch by 4-inch by 16-inch concrete prism specimens.

Figure 4. Freeze-Thaw Chamber.
  This image shows a research engineer in a laboratory. The engineer is reading the electrical resistance of a concrete cylinder by using a four-point Wenner probe.

Figure 5. Surface Resistivity Apparatus.

The Concrete Laboratory also performs shrinkage tests that include restrained shrinkage tests and autogenous shrinkage tests. The mechanical properties measurement equipment includes a universal testing machine with a capacity of 4,500 kilonewtons (1,000,000 pounds) and a beam tester with a capacity of 130 kilonewtons (30,000 pounds), a compressometer/extensometer, and four creep frames.

Laboratory Services: The Concrete Laboratory provides support in the following areas:

  • Evaluates and develops new or improved equipment and procedures for assessing the properties and performance of concrete, including materials selection, mixture proportioning, and construction of concrete.
  • Mixes, casts, and tests concrete test specimens in support of other researchers at the Turner-Fairbank Highway Research Center.
  • Investigates the properties and performance of concrete and its component materials (cement, aggregate, and supplementary and alternative cementitious materials admixtures, etc.).
  • Performs specialized testing and forensic investigations on concrete to assist State departments of transportation and other research offices and divisions within the Federal Highway Administration.

 

Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000
Turner-Fairbank Highway Research Center | 6300 Georgetown Pike | McLean, VA | 22101