248-MMB : Methods of measuring moisture in building materials and structures

Technical Committee 248-MMB

General Information

Chair: Prof. Lars-Olof NILSSON
Deputy Chair: Prof. Kurt KIELSGAARD HANSEN
Activity starting in: 2012
Activity ending in: 2017
Cluster B

Subject matter

Properties and performance of building materials and structures are to a large extent influenced by the moisture conditions in the materials. Obvious examples are heat conductivity, shrinkage and creep, transport properties, most types of deterioration, discolouration etc. For research and applications the moisture conditions must be quantified, by measurements in the laboratory or under field conditions. The methods being used today are very different in different countries, very different for different materials and very different for different applications. Also researchers within the same topic use different methods. No consensus whatsoever does exist.

There are a number of aspects that merit further attention:
• The applications of different types of equipment/measuring principles; their advantages and drawbacks.
• Measuring moisture content or state of moisture; suitability for different applications.
• Measuring moisture in different materials; background to traditions and possibilities of using new alternatives.
• Uncertainties in moisture measurements.

For the construction industry it is important to be able to quantify the moisture conditions in an accurate way in various applications.

Terms of reference

The TC is supposed to run for 4 to 5 years. Members will be recruited from academia and industry, based on their experience with methods for measuring moisture conditions. The work will include literature research and exchange of good practices information to publish a state-of-the-art report. A number of round-robin tests will be the base for recommendations for measuring methods in various scientific and industrial applications.

Detailed working programme

The committee work is planned to follow this time-line: 
- a start-up meeting: introduction of members, suggestion of new members, overview of members’ competences and experience, plan of activities, list of contents for a state-of-the-art report, organisation of an initial workshop
- a small workshop for the members, in order to get an overview of experience, problems and points of attention related to the methods used by the members; decision on most important points for further TC work
- committee meetings with discussions on drafts of the state-of-the-art report, exchange of information between TC members, compilation of sheets with best practices etc.
- round robin tests for selected measuring methods,
- an international conference,
- recommendations of selected methods for measuring moisture in construction materials,
- organisation of a short doctoral course
- publication of TC findings in one or more journal papers.

Technical environment

The topic of methods for measuring moisture in construction materials in general fits into the scope of RILEM as an organisation dealing with a range of construction materials and structural performance. The idea for this committee was initiated by the first European conference on moisture measurements, Aquametry 2010, which dealt with moisture measurements in a wide area of applications, from space to construction. The methods used for moisture measurements in materials are more or less based on the same principles but the degree of development is very different in different disciplines. Here we could learn a lot from other scientific and industrial fields.

Expected achievements

Expected achievements from the committee are
- improvement and distribution of the knowledge related to moisture measurement in construction materials in various scientific and industrial applications
- quantification of the uncertainties in various methods for measurement of moisture contents and state of moisture
- connection of researchers working in the field of moisture measurements in different materials and applications and agree on good practices
- best practices sheets and recommendations for researchers and/or practitioners
- summary of TC findings in a state-of-the-art report
- an international conference and conference proceedings for further dissemination of information
- possibly a doctoral course on moisture measurement in construction materials (e.g. one-day course connected to the final conference of the TC)

Group of users

Academics, testing laboratories, industrialists, practitioners

Specific use of the results

A common application in many countries is measurement of moisture in concrete floor slabs before applying a moisture-sensitive and impermeable flooring material. Today this is done in many different ways in different countries, also within each continent. Better and more accurate methods for measuring moisture would significantly limit the risk of damages due to moisture and the waist of construction time for further drying.
Moisture measurements in wooden materials are performed all over the world for many industrial applications: control of drying, delivery checks, controls during construction, long-term performance controls of structures etc. More accurate methods with better long-term reliability would decrease the risk for mould growth and root decay in wooden structures.