Concrete Laboratories

Portland Cement Concrete Pavements Research

Location:	Fairbank Building, Rooms G-14, G-17, G-18, G-20, G-22, G-23, and F-107
Lab Managers:	Richard Meininger, Pavement Materials and Construction Team Ph: (202) 493-3191, richard.meininger@fhwa.dot.gov
Lab Managers:	Jack Youtcheff , Pavement Materials and Construction Ph: (202) 493-3090, jack.youtcheff@fhwa.dot.gov

Testing Equipment The Concrete Laboratories consist of several laboratories that are equipped with standard laboratory equipment (ovens, scales, etc.), as well as specialized equipment for concrete testing. The laboratories function as a unit to provide facilities for research on portland cement concrete and its constituent materials.

Purpose

To investigate the properties and performance of portland cement concrete (PCC) and its component materials (cement, aggregate, admixtures, etc.).
To evaluate and develop new or improved equipment and procedures for assessing properties and performance of PCC, and practices for materials selection, mixture proportioning, and construction of PCC.
To support other TFHRC researchers in mixing, casting, and testing of portland cement concrete test specimens, and to support State DOT's by testing and performing forensic investigations on portland cement concrete from existing pavements and structures.

Description

The Aggregate and Sample Preparation Laboratory provides facilities for the preparation of aggregate samples for concrete and the preparation of hardened cement paste, mortar, or concrete specimens for testing and analysis. Equipment includes two rock crushers, a pulverizer, a vibrating screen, a Gilson TestMaster, standard sieves, a Videograder (for automated sizing and shape analysis of aggregate), two water-cooled saws, lapping wheels, a lathe for profile grinding, and a muffle furnace.

The Concrete Curing/Maturity Laboratory provides facilities for curing of concrete specimens under standard or other controlled conditions and assess of curing-related properties such as degree of hydration, maturity, and shrinkage. Equipment includes three heated curing tanks, two walk-in environmental chambers (8 ft by 8 ft), and a 50-gallon water bath.

The Concrete Durability Laboratory provides facilities for investigating the effects of chemical and environmental exposure on concrete. The laboratory is equipped to assess alkali-aggregate reaction, sulfate attack, chloride penetration, freezing and thawing and thermal effects. Equipment includes an automated freeze-thaw, chamber with the capacity for 60 specimens, thermal coefficient test frames (developed in-house) and bath, and computer- controlled chloride penetration test equipment.

The Mechanical Properties Laboratory provides facilities for testing the mechanical properties of concrete, steel, and composites. Equipment includes three servo-controlled universal testing machines with capacities ranging from 60,000 to 400,000 lb, a 1,000,000-lb compression testing machine, a compressometer/extensometer, and four creep frames.

The Plastic Concrete Laboratory provides facilities for batching and mixing cement paste, mortar, and concrete, and for performing tests on fresh (plastic) cement paste, mortar and concrete. Two drum mixers and a 2 cubic foot pan mixer are available for mixing.

The Petrographic Laboratory provides facilities for preparing for and conducting petrographic and microscopic investigations of aggregate, PCC, and asphalt concrete. Equipment includes several types of microscopes (including an epi-fluorescent polarizing microscope), a semi-automated air void analysis system, image analysis hardware/software, and thin-section preparation equipment.
Petrographic Methods of Examining Hardened Concrete: A Petrographic Manual, FHWA-HRT-04-150, July 2006

Accomplishments

Recent Activities:

Past outputs, results, and products include an AASHTO provisional standard test method for measurement of the coefficient of thermal expansion (CTE) of concrete, papers presented/published on thermal coefficient testing, Alkali Silica Reaction (ASR) testing, freeze-thaw durability, mixture optimization, and assistance provided to Texas, Pennsylvania, Missouri and other States.

Current Activities:

Projects include investigation of ASR test methods for concrete mixtures, investigation of the durability of concrete with marginal air contents and improved methods for characterizing damage in freeze-thaw tests, investigation of statistical methods for optimizing concrete mixture proportions, development of an interactive website for mixture optimization, evaluation of the effectiveness of moist curing, and on-going assistance to States and other researchers at TFHRC, and CTE testing in support of the LTPP program.

Partnerships and Customers

The Concrete Laboratories have been, and are currently, involved in cooperative efforts with various partners. The laboratories also provide assistance to customers such as State DOTs and other FHWA researchers. Current/recent examples are listed below:

Cooperative research with National Institute of Standard and Technology (NIST) on concrete mixture optimization and curing.
Assistance to Missouri DOT on a project involving image analysis of air voids in concrete.
Assistance to Pennsylvania and Texas in testing for research projects on ASR and high-performance concrete, respectively.
Participation in the field evaluation of a new test method for an FHWA contract project on chloride penetration.
Materials testing for the ALF/UTW project (sponsored by industry).
Support for other FHWA research efforts at TFHRC involving concrete, such as research projects on DEF and chloride assessment.

Portland Cement Concrete Pavements Research