Facilities

FACILITIES

Concrete Mixing Laboratory
Concrete Strength Testing
Environmental Durability
Pore Structure Analysis
Thermal Analysis and Calorimetry
Micro-Imaging
Full Scale Pavement Slab Testing

Concrete Mixing Laboratory

In the mixing lab we have a large pan mixer and a drum mixer. These mixers are used in preparing any concrete for testing. Located in the aggregate lab we have two mechanical shakers. The one shown above uses standard sieves to perform a gradation analysis. The second shaker in this lab is larger pan style shaker for coarse aggregate sieving. Also located in the aggregate lab is an area for conducting sulfur capping of concrete samples. A mortar cube testing machine and aggregate drying oven are also located in this lab. Once samples are prepared in the mixing lab they are placed into water tanks located in the aggregate lab.

Concrete Strength Testing

Our laboratories are equipped with state of the art concrete testing equipment from MTS Corporation. The labs include two servo-hydraulic controlled testing machines, one with a 1,000,000 lb. capacity in compression and one with a 110,000 lb capacity in tension and compression. The smaller machine is dedicated to tension and flexure testing, while the larger is used primarily for compressive tests. Closed loop control allows for detection of post peak behavior, even in highly brittle materials.

In addition to the large concrete testing machines, a smaller screw-driven MTS machine with a 2kN capacity load cell is used for fiber pull-out measurements and very small specimen testing.

Environmental Durability

Environmental control during curing and testing can be critical to concrete testing. A large temperature and humidity controlled chamber allows for controlled environment curing as well as creep and shrinkage measurement. The chamber can also be controlled for variable conditions, allowing field conditions simulations.

To test the performance of concrete in freeze-thaw conditions we use the machine shown above. This machine is capable of varying the temperature of concrete beams over an extended duration. This freeze-thaw machine has been very helpful in evaluating the performance of different aggregates to freeze thaw conditions.

Pore Structure Analysis

To measure the development of pore structure in hydrating portland and blended cements pastes we use Mercury Intrusion Porosimetry (MIP) Method, Helium Pycnometry, and Nitrogen Sorption Analysis. All of these methods are used to study various properties of concrete. These properties include pore size, permeability and total pore volume. All of these methods are conducted at the PRCE.

Thermal Analysis and Calorimetry

The amount of hydration and secondary products that have been formed overtime can be measured by using thermal analysis techniques. Thermal analysis involves heating a sample to extreme temperatures and measuring the products being burned off at different temperatures. This allows for quantification of the degree of reaction development for different cement systems.

Micro-Imaging

To investigate the microstructure of various concrete specimens we use two high powered microscopes that can take photographs or display the image on a television monitor. These microscopes are also used to get a closer look at base coarse and subbase soil samples.

Full Scale Pavement Slab Testing

Located with in the mixing lab is thermal stress cracking frame. This MTS machine is designed to measure the stress induced into the concrete pavements by temperature.