Technical Committee 266-MRP
Deputy Chair: Dr. Dimitri FEYS
The purpose of this RILEM Technical Committee is to compile available information on measuring rheological properties of cement-based materials: namely cement paste (or grout), mortar and concrete. Rheological models, measuring procedures and available tools will be reviewed. The work of this committee is based on literature review and experiences from the committee members. The subject of this committee can be regarded as an extension of the work in RILEM TC 209 (Rheology of cement based materials such as fresh concrete). The work of the committee will only focus on the measurement of the properties themselves, not on the causes of changes in rheological properties, neither on the consequences of rheology in different situations. The work will only be based on literature, creating a state-of-the-art report and, upon consensus, recommended procedures to measure rheological properties. The committee has no intention to perform a comparative study of different rheometers. Based on the outcome of this committee, this could however form the basis for a follow-up committee. In the end, the importance of the measurement procedure on the rheological properties will be more emphasized to the community.
Terms of reference
The time frame estimated to achieve the three goals of this committee, listed below, is five years. Supposed the committee starts in the Spring of 2015, the time frame for the three goals is proposed as follows:
- State-of-the-art report: Spring 2015 to Spring 2020
- Recommended procedures: Spring 2016 – Fall 2018
- Course, workshop or webinar: Spring 2018 – Spring 2020
Based on feedback from potential members, a total of 15 to 20 members are anticipated, mainly originating from Europe and North-America. Most potential members are related to academia (including students), while some individuals from industry have shown interest to participate in this committee. New members are welcome, and as most of the meetings will be organized in parallel to major conferences related to the topic, exposure to new members will be enhanced.
No experimental work will be performed, neither will new equipment be created. The information available in literature will be compiled into the report and recommendations.
Detailed working programme
The purpose of this committee is three-fold:
- Create state-of-the-art report on the measurement of rheological properties of cement-based materials
- Propose recommended procedures or best practices to measure rheological properties
- Educate concrete technologists, regardless whether they are in academics or in practice, through potentially a course, workshop, or webinars.
The creation of the state-of-the-art report will be ongoing for the entire duration of the committee. The amount of information available in literature is extensive. Information will be gathered on the different rheological properties, whether in steady-state (yield stress, viscosity, non-linearity) or transient in time (thixotropy and workability loss). For each set of properties, information on tools (rheometers) will be collected and described. Different measurement procedures and measuring artefacts will be discussed and it will be mentioned how they can influence the obtained properties.While assembling information for the state-of-the-art report, best practices or recommended procedures for measuring the rheological properties of cement-based materials will be discussed. Upon consensus in the committee, these recommendations can be bundled in a separate document. The purpose of this document is to train users of rheology in how to assess rheological properties of cement-based materials and make them aware of potential measurement artefacts resulting in wrong conclusions or making the data set invalid.Based on the recommended procedures or best practices, the information will be spread out to new and existing users of rheology in the field of cement-based materials. These new users could be new graduate students in an academic environment or could be concrete specialists in a more practical setting. This outreach task can be completed by organizing a course or a workshop, potentially associated with a conference in the field, or by creating a series of webinars, readily available to the user.
The most appropriate RILEM cluster for this TC is A. Material Processing and Characterization. The main relevance of this TC to RILEM’s mission would be:
- The collective advancement in scientific knowledge, as the available information will be compiled into one document.
- The encouragement of transfer and application of this knowledge world-wide, through the creation of the best-practices and the organization of the outreach activities.
The science of rheology of cement-based materials has been discussed in several former and existing RILEM committees, such as TC 145 (Workability of special concrete mixes), TC 209-RFC (Rheology of cement based materials such as fresh concrete), TC 244-NUM (Numerical modelling of cement-based materials) and RILEM TC 233-FPC (Form pressure generated by fresh concrete). Furthermore, rheology is intensely discussed in two technical committees of the American Concrete Institute (ACI), namely ACI-237 (Self-consolidating concrete) and ACI-238 (Workability of concrete). Exchange of information between the existing committees and the proposed RILEM TC will be intensified. Furthermore, interaction can be enhanced between the proposed committee and different branches of the Society of Rheology.
The deliverables of the proposed TC will be the result of the three different tasks.
- State-of-the-art report on measuring of rheological properties of cement-based materials, bundling the information available in literature into one document.
- Recommendations for testing procedures further extend the state-of-the-art report in providing guidelines for measuring specific rheological properties (including the argumentation on how the guidelines were established).
- Improvement and dissemination of the knowledge related knowledge to the “users” in academia and in practice, through the organization of life or virtual technology transfer events, such as a workshop, a course or a webinar.
Group of users
Academics, testing laboratories, industrialists, practitioners, general public, Ph.D students, other: rheometer producers.
Specific use of the results
The purpose of the work performed in the committee is to enhance the reliability of rheological measurements performed on cement-based materials. The benefit is scientific in nature, as the produced documents (and other tech transfer activities) will make users more aware of potential sources of errors in the measurements and provide guidelines on how to observe, counteract or eliminate the errors. Improving the reliability of rheological measurements will further enhance the use of rheology to investigate different aspects of the fresh properties of cement-based materials. For example, the documents could be very useful to a starting graduate student who wants to use rheology to characterize cement-based materials. The student will be given an overview of different measurement procedures and potential artefacts and guidelines to counteract these problems, while he/she is referred to specialized literature for more detailed information. In this way, this person can critically analyse the measurement of rheological properties from day 1.