Infrastructure

Building Materials at Lund University has a long tradition of working with concrete. We therefore have a small concrete production facility with all the equipment necessary for making both small and large concrete specimens. Among the equipment is:

• Three concrete mixers
• Vibrating tables and rods
• Standard steel forms
• Curing baths
• Diamond saw and core drills for taking out samples
• A workshop for making of ad-hoc forms

In our mortar laboratory we have:

• Two sieve stations
• A standard (Hobart) mixer
• Several other small mixers

We also have several climate rooms for storage of samples during curing.

Frost damage to concrete has been a major subject at Building Materials at Lund University for many years. For such studies we have the following equipment:

• One Setaram scanning calorimeter
• One programmable freezer
• Standard freezers
• One home-built calorimeter-dilatometer for studies of frost damage phenomena

Building Materials at Lund University have a long experience both with full scale testing within our own facilities and measurements in the field. For example, we have recently worked with the following:

• Full scale testing of the tendency of cracking of rendering on insulation (in laboratory)
• Measurements of movements in hydroelectric power dam (in the field)
• Measurements of moisture profiles in nuclear power plant (in the field)

Isothermal calorimetry is the measurement of heat and heat production rate from different processes (physical, chemical, biological) under constant temperature conditions. Different principles can be used for such instruments; at Lund University we have a long tradition in designing heat conduction calorimeters, but we also work with quasi-adiabatic instruments. Samples usually have a volume between 0.5 and 20 mL.

The main aim is to design instruments and methods to help other researchers perform their work more efficiently. We specialise in putting things together in novel ways to make new types of measurements possible and have access to the entire lab full of parts and calorimeters. Below is a partial list of the equipment that we have:

• Five TAM Air calorimeters (20 mL, eight channels each)
• Eight admix ampoules for the TAM Air
• One BAM thermostat with four microcalorimeters (3-4 mL)
• One BAM thermostat with a sorption microcalorimeter
  Information about sorption calorimetry (Lund University's Research Portal)
  More about applications of sorption calorimetry (Lund University's Research Portal)
• A thermostat with three microcalorimeters (20 mL)
• One 16 channel calorimeter (3mL)
• One sorption calorimeter with an air thermostat
• One isothermal calorimeter that measures at four different temperatures
  Article about biological applications of isothermal calorimetry (Lund University's Research Portal)
• Three student calorimeters (20 mL, four channels each)

Together with other divisions we share a number of mechanical testing machines that are used both in research, in teaching and for contract work. The mechanical testing instruments that we most commonly use are:

• A concrete cube/cylinder press
• An axial servohydraulic mechanical testing machine, maximum load capacity 100 kN (MTS Systems Corporation)

The Building Biology group has a microbiological laboratory for culturing non-toxic organisms. We mainly work with mold and rot fungi, but have also done some work on algae.

For many years, Building Materials at Lund University has been specialists in material properties related to water and water vapor and our laboratory is very well equipped for measurements of such properties. Below follows a list of the equipment in our sorption and transport laboratory.

Sorption balances*

We have six high end sorption balances from Surface Measurement Systems Ltd:

• one DVS 1000
• two DVS Advantage both equipped with 0.1 µg Cahn microbalances
• two DVS Intrinsic
• one DVS Resolution

With these versatile instruments we mainly measure sorption isotherms, but we also use them for, e.g., measurements of transport coefficients, hydroxyl accessibility and film formation.

• Example of measurements of sorption isotherms (Lund University's Research Portal)
• Article about measurements of transport coefficients (Lund University's Research Portal)
• Example of measurements of hydroxyl accessibility (Lund University's Research Portal)
• Example of measurements of film formation (Lund University's Research Portal)

Jar method (sorption isotherms)* 

This is a low tech set-up for measuring sorption isotherms in which each sample is suspended in a glass jar with a saturated salt solution that produces a fixed RH. It is also suitable for small samples as one can weigh the samples without opening the jars.

More information about the jar method (Lund University's Research Portal)

Box method (sorption isotherms)*

For larger samples – for example of concrete – we equilibrate the samples over saturated salt solutions in boxes equipped with fans.

RH-sensors

We have a large number of different types of RH-sensors, from hand-held devices to standalone loggers that can collect RH and temperature data. We calibrate these sensors in our Thunder climate chamber.

Thunder climate chamber (RH-sensor calibration)

Our Thunder climate chamber (Thunder Scientific Corporation Model 2500) is a two-pressure device traceable to NIST/NPL in which we calibrate RH-sensors, both our own and sensors belonging to consultants and other external customers.

More information about the Thunder Scientific Corporation Model 2500 (Thunder Scientific webpage)

Cup method (diffusion coefficients)

In the cup method a sample is placed as a lid on a cup containing a saturated salt solution with a fixed RH. When the cup is placed in another fixed (external) RH the measured mass loss rate of the cup is proportional to the diffusion coefficient. We have two types of cups for steady-state measurements of diffusion coefficients. One is made of polypropylene and is possible to open, enabling changing/refilling of the salt solution, and the other is made from glass. In both methods the disk shaped samples are fastened to the cup with water impermeable sealants.

More information about the cup method (Lund University's Research Portal)

Pressure plate laboratory

We have a unique, custom built pressure plate laboratory with 20 small pressure plate cells which can be used to condition samples to high moisture states. The maximum pressure of these cells are 5 bar, which corresponds to a relative humidity of 99.63%.

More about the custom built pressure plate system (Lund University's Research Portal).

In addition, we have five pressure extractors from SoilMoisture Equipment Corp. with the following maximum pressures: 100, 15 and 5 bar.

Climate rooms

Together with other divisions in our building we have several climate rooms (some only temperature controlled; others with both temperature and RH control). In these we can – for example – do cup measurements.

Sorption calorimeters

A unique instrument to study sorption phenomena with is the SORP sorption calorimeters that have been developed at the division. These instruments are mainly used for pharmaceutical substances, polymers and bio-molecules.

Information about sorption calorimetry (Lund University's Research Portal)
More about applications of sorption calorimetry (Lund University's Research Portal)

* The three methods to measure sorption isotherms all have their advantages and disadvantages. The sorption balances are normally used for small (10-100 mg) samples, the jar method for larger samples (10 g), while the box method is suitable for even larger samples. When we have many samples, the jar and box methods are used, as one with these methods can run many samples in parallel. The sorption balances have the advantage of being able to produce complex RH-schedules, for example for scanning studies.

For many years, the Thermal properties laboratory Building Materials at Lund University has been specialists in material properties related to water and water vapor, for example diffusion coefficient and sorption isotherms. During the last five years we have complemented this with a thermal properties laboratory, as both thermal and water related properties are needed by e.g. the construction industry and the pharmaceutical industry.

Our thermal property laboratory consists of two parts: measurements of thermal conductivity and volumetric heat capacity with a HotDisk instrument, and measurements of more complex thermal properties by calorimetric techniques.

Hot Disk instrument

We have a HotDisk 1500 from Hot Disk AB that simultaneously measures thermal conductivity and volumetric heat capacity of solid samples. The patented technique is unique in its versatility; a combined heater and temperature sensor is placed in contact with a material and the temperature change of the sensor following a heating period is monitored. Because of the unique shape of the sensor, it is possible to calculate both the thermal conductivity and the volumetric heat capacity (and thus the thermal diffusivity) from the rate of temperature change.

The sample has to have a plane surface, a thickness that is larger than the diameter of the sensor, and the sensor should be much larger than the largest components (phases). We have sensors with diameters between 13 and 49 mm.

We have used the instrument on different types of materials with good results, for example in a study of the thermal properties of concrete. The only limitation is that we cannot measure on smaller objects than about 20 mm x 20 mm x 12 mm.

Differential Scanning Calorimeter

We have a Differential Scanning Calorimeter (DSC) from Mettler Toledo. It is a DSC3+ with a TC-100 intracooler and a sample robot for 34 samples. The temperature range is from -90 to 500 °C.

Measurements of complex thermal properties

With our equipment in our isothermal calorimetry laboratory we can measure such thermal properties as:

• Enthalpies of condensation/vaporization
• Enthalpies of solidification/melting
• Enthalpies of crystallization and other phase changes
• Specific heat capacities

Such measurements are tailored to the specific needs of our projects or customers.

One example of this type of measurement use was the determination of the enthalpy of crystallization of aqueous solutions of sodium acetate that are used in for example rechargeable hand-warmers.

n all our courses, laboratory work is an important part of the learning process. The aim is to promote active learning by hands-on activities in the lab. Below are some examples of experimental work that the students do in our courses.

Building Materials (VBMA30 and VBMA35)

These courses are basic mandatory courses given at the Civil Engineering programme (“V-programmet”) and the Fire Safety Engineering programme (“Bi-programmet”), respectively. The laboratory work in these courses involve:

• Cast concrete cubes and measure the compressive strength.
• Determine the particle-size distribution of ballast.
• Measure temperature induced deformations of acrylic plastic and glass.
• Study shrinkage of wood veneer.
• Determine water vapour diffusion coefficients of different materials by the cup method.
• Determine stress-strain curves for reinforcement bars and plastic.
• Study creep behaviour of moist board materials.

Building Materials (VBMA05)

This course is a basic mandatory course for Architect students (“A-programmet”). The laboratory work in this course involves:

• Cast concrete cubes and measure the compressive strength.
• Determine the particle-size distribution of ballast.
• Study moisture uptake of different building materials.
• Thermal properties of floor materials.
• Identification of different wood species.
• Measuring swelling of wood.

Building Materials (VBMA35)

This is a basic mandatory course for Bachelor's students in Civil Engineering with Architecture. The laboratory work in this course involves:

• Cast concrete cubes and measure the compressive strength.
• Determine the particle-size distribution of ballast.
• Determine stress-strain curves for reinforcement bars.
• Determine water vapour diffusion coefficients of different materials by the cup method.
• Measure temperature induced deformations of acrylic plastic and glass.
• Testing of different instruments for moisture monitoring.

Building Material Science (VBMF05)

This course is given as an optional course at the Civil Engineering programme (“V-programmet”)

• How does rechargeable hand-warmers work and how can one create sub-zero temperatures with ice and salt? (thermodynamics).
• The heat production when gypsum is formed and the rate of dissolution of a spherical particle (kinetics).
• The scanning electron microscope (SEM).
• Diffusivity – a most important transport property.

Biobased Building Materials (VBMN20/TFRP10)

This course is an advanced course given at the Civil Engineering programme (“V-programmet”) and as a single course. The course is also open for exchange students. The laboratory work in this course involves:

• Identification of different wood species and engineered wood products.
• Studying microstructure of biobased building materials by microscopy.
• Measuring moisture sorption properties of wood with different densities.
• Understanding moisture induced deformations in wood by making materials of veneer and study deformations after water soaking.
• Investigating how wood modification change moisture sorption properties and dimensional stability.

Concrete in a life cycle perspective (VBMN20)

This is an advanced course given at the Civil Engineering programme (“V-programmet”). The laboratory work in this course involves:

• Design a concrete mixture according to certain requirements.
• Determine the strength of that concrete mixture.
• Determine different moisture states of that concrete.
• Measure the temperature development and develop a simple temperature simulation tool for that concrete mixture.

Master's and Bachelor's theses (VBMM01 and VBML05)

Our laboratory facilities are used extensively by our students working on their Master's or Bachelor's thesis projects. Most of these projects are based on laboratory work and the students then also get access to our more advanced instruments.