Laboratory for the science of sustainable infrastructural materials
- Thermogravimetric analyzer
- Differential scanning calorimeter
- Mercury Intrusion porosimeter
- Electrical impedance spectroscope
- Fourier Transform Infrared spectroscope (with ATR attachment)
- TAM Air – Isothermal calorimeter
- I-Cal – Isothermal calorimeter
- Optical microscope
- Mechanical test frame
- Chloride ion transport test system
Structural Engineering Laboratory
- Mechanical test frames – MTS
- Compression test frame
- Digital image correlation test set up
- Small scale mechanical test system
- Environmental chamber
- Early age volume change and crack characterization system
- Guarded hot plate for thermal conductivity measurement
- High Resolution X-ray Diffractometer (Panalytical Xpert Pro)
- SEM – XL30 Environmental FEG (FEI)
- Electron Microprobe (JEOL JXA-8530F Hyperprobe)
- Ion Beam Analysis of Materials (IBeAM)
- FT-Raman (BRUKER IFS 66V/S)
Physics NMR facility
- NMR spectroscope
Thermogravimetric analysis is a quantitative technique that allows to measure the mass loss and heat flow associated with heating a sample. The instrument is capable of handling temperatures ranging from 15 C to 1000 C. Different reaction products in the sample decompose over different temperature ranges which is identified by the mass loss profile of the sample. The heat flow profile is used to identify the type of reaction products formed in the sample.
Differential scanning calorimetry (DSC) is a thermo-analytical technique that measures difference in the heat flow rate between the sample and the inert reference with varying time and temperature. The basic principle is that the sample absorbs or releases heat during a phase transformation and more or less heat flows in the sample as compared to the reference to increase the temperature by a specific amount depending upon the transformation being endothermic or exothermic. DSC keeps track of the amount of heat released or absorbed in such transitions by measuring the difference in heat flow between the sample and the reference and provides useful information about the phase transition temperatures of the sample. In DSC, samples should be distributed uniformly across the bottom of the pan. The pans are either alumina or platinum depending on the temperature range experienced or reactivity of the sample material with the pan material. For determination of phase transitions, DSC scans can be carried out at various rates from 0.1-100 °C/min and can span a temperature range of -80 °C to 600 °C. All scans are maintained and completed in a flowing-N2 atmosphere and take between 0.5-3h to complete (dependent on the rate).
Fourier Transform Infrared spectroscope (with ATR attachment)
Attenuated total reflectance – Fourier Transform Infrared Spectroscopy (ATR-FTIR) allows for the determination of transmission spectra without destructive sample preparation. Spectra are obtained from the absorption or transmittance of a wave which is transmitted through an internal reflection element (IRE) of high refractive index and penetrates a short distance into the sample, in contact with the IRE. The IRE used is a diamond, selected because of its resistance to high pH and abrasion from sample removal and cleaning.
Chloride Ion Transport Test System
The chloride ion transport test system causes chloride ions to penetrate a concrete sample under an externally applied field and a concentration potential. These tests are chosen over regular saturated diffusion tests because of the shorter duration time and ease of use. The main idea of the test is to observe the durability characteristics of concretes such as chloride ion induced reinforcement steel corrosion. There are two standards for which the test is performed: Rapid chloride penetration test (RCPT, ASTM C1202) and the Non-steady state migration (NSSM, NT Build 492). RCPT provides an indication of the resistance of concretes to chloride ion penetration under an externally applied potential of 60 volts and records the total charge passed through the specimen after a testing duration of 6 hours. NSSM provides an indication of the resistance of concrete to chloride ion penetration based on the initial current value when a 30 volt external potential is applied, and provides an NSSM migration coefficient calculated using the average values of the measured penetration depth after a testing duration of 24 hours. The experimental set-up for the RCPT and NSSM test is a Germann Instruments PROOVE’it Rapid Chloride Permeability Test System. The set-up involves a cathode cell containing NaCl solution and an anode cell containing 0.3 N NaOH solution. Penetration depth is measured after the sample is axially split and 0.1 M silver nitrate is sprayed on the interior surface and the white silver chloride precipitates.
MTS mechanical testing system
The state-of-the-art closed loop high-performance digital servo-controlled MTS mechanical testing system has a capacity of 22,000 lbs. With an integral actuator, crossheads, and force transducers, this machine is used for tension, high cycle fatigue, low cycle fatigue, creep, fatigue crack growth, and fracture toughness of materials. Mid-scale experiments using closed loop controlled tension, flexural, compression, and fracture tests can be conducted using this equipment.
Compression test frame
Servo hydraulic-controlled SBEL uniaxial compression mechanical test system has a capacity of 110,000 lbs. It is used for evaluation of compressive stress-strain response, captured by data acquisition system attached to the instrument. Cylindrical systems are used for testing.
VIC-3D™ Measurement System for digital image correlation (DIC)
DIC is a speckle tracking method that is used to determine the displacements of speckles in a digital image. It is a non-contact optical method for measuring full-field displacements and strains utilizing a pair of stereo-mounted digital cameras. The VIC-3D™ system offers good speed and accuracy for a wide range of quasi-static and dynamic applications. The measurement system has a high strain resolution of 0.005% (50 microstrain) or better. A wide range of strains can be measured (0.005% (global) to 2,000%). It offers resolution up to 1/100,000 and 1/50,000 times field of view for in-plane and out-of-plane direction respectively. DIC provides very useful information for evaluation of crack-propagation and strain-localization mechanisms in cementitious composites.
Guarded hot plate for thermal conductivity measurement
The Guarded-Hot-Plate Apparatus provides a means for measurement of steady state heat flux through a wide variety of materials. It consists of a guarded heater unit, a centralized metering area, concentrically separated heat guards, and similarly sized cooling plates. Specimens are placed in the space between the heater plate and the cooling plate for testing. The guarded-hot plate is operated as a single or double sided apparatus. Thermal conductivity of the tested specimen is calculated from measurements of metering area, energy input, temperatures, and thickness.
The diffractometer can operate at up to 900°C using CuKα radiations. The instrument can characterize crystal orientation, degree of crystallinity, stresses in the crystal structure, spatial mapping (100 x 100 mm motion) of sample surfaces, high speed wide angle x-ray diffraction and fast mode reciprocal space mapping etc. It contains three sample stages: (i) Standard 4” wafer mount, (ii) Solid sample holder (also used for powders), (iii) Anton Paar DHS 900 domed hot stage for data collection from room temperature up to 900 °C. It is also equipped with PANalytical X’Pert HighScore Plus Software for phase identification.
SEM – XL30 Environmental FEG (FEI)
The XL30 ESEM-FEG offers high resolution secondary electron imaging at pressures as high as 10 Torr and sample temperatures as high as 1,000°C. Hence, wet, oily, dirty, outgassing, and non-conductive samples can be examined in their natural state without significant sample modification or preparation. The XL30 ESEM-FEG employs the stable, high brightness Schottky Field Emission Source for outstanding observation performance of potentially problematic samples for conventional high vacuum SEMs.
Electron Microprobe (JEOL JXA-8530F Hyperprobe)
The JXA-8530F consists of a Field Emission Scanning Electron Microscope (FESEM) surrounded by five Wavelength Dispersive Spectrometers (WDS). The combination of WDS and EDS makes it a very powerful analytical tool. The five WDS’s provide a wide wavelength range covering elements from Be (Z=4) to U (Z=92). This instrument can do accurate quantitative analysis including map analysis, phase analysis and line analysis. Quantitative analysis requires a suitable combination of grinding and polishing (using Allied High Tech – MultiPrep™ Polishing System) to achieve a desired level of flatness.
Ion Beam Analysis of Materials (IBeAM)
The IBeAM facility consists of a 1.7 MeV tandem accelerator with a beamline and analysis chamber. The facility has the following instrumentations: (i) Ion beam analysis (IBA) using MeV ion beams for compositional and structural determination of materials; (ii) Rutherford backscattering (RBS) for surface analysis using recoil energies of accelerated ions (e.g., He or H) to determine the species and depth profiles of atoms in a given sample and (iii) X-ray analysis (Proton Induced X-ray Emission – PIXE) which has the advantage of a much improved signal/noise ratio when compared to electron induced X-rays.
FT-Raman (BRUKER IFS 66V/S)
The instrument can work under vacuum environment (< 5 mbar) (in the main bench) and it is capable of microscope transmission and reflection. It covers a full spectral range from ~10 – 12000 cm-1. Fluorescence can be avoided for macro samples in FT-Raman (from ~100 to 3500 Rcm-1) by using a YAG laser (1064 nm). The instrument includes: (i) bench detectors (Bolometer (far IR), DTGS (mid-far IR), Wide-band MCT (mid – near IR)); (ii) microscope detectors (Wide-band MCT (mid – near IR), Wide-band InSb (near-IR)); (iii) beam splitters (KBr (near IR, Mid IR), CaF2 (near IR, mid IR), 6 μm Mylar (far IR)); (iv) sources (Globar (near IR, mid IR, far IR), W lamp (visible, near IR)) and (v) different sample accessories such as Harrick ATR-GATR (for Analysis of monolayer on metals and monolayer on silicon by FT-IR ATR spectroscopy, Measurements of adsorbed species on semiconductors or on metals) and Seagull Variable angle reflectance.