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The RILEM AAR-13 test procedure is not a test method by itself; rather it is a procedure applying alkali wrapping to concrete prisms during test exposure to assess the expansion potential of alkali-silica reaction. When combined with procedures of other test methods, for example AAR-10 or AAR-11, it becomes a full test procedure. The wrapping procedure described was originally proposed by a technical committee of the Japan Concrete Institute “Technical Committee on Performance Based Design and Maintenance Scenario with Controlling ASR Deterioration”. The procedure includes a detailed description of the materials to be used for wrapping, procedures for calculation of alkalinity of the solution that aims to simulate the pore solution of the concrete prism depending on the alkali content of the concrete, and finally specific procedures for storage and measurements of the prisms. The procedure of calculating the alkalinity of the solution to be applied for the wrapping is assumed to be conservative because no subtraction is made for assumed alkali binding by the hydrates or alkali absorption by the aggregates. The alkali content is estimated by adding the alkali contribution from all concrete constituents (except the aggregates) including the supplementary cementitious materials (SCMs).

In the last years, RILEM Technical Committee 237-SIB proposed a new test protocol for reclaimed asphalt pavement (RAP) characterization, the cohesion test, with the goal to facilitate the identification of the most suitable solution for the recycling within new pavement layers. However, this procedure actually allows discriminating between different RAP sources but it does not exactly indicate the effective “activity” of the binder in the RAP. The present paper deals with the analysis of different RAP materials through the RILEM cohesion test. In particular, two “young” RAPs, different in composition and milled immediately after being laid, were aged in the laboratory and tested at different ageing levels. Moreover, an in-site aged RAP was tested as reference, either in neat conditions or after being sprayed with a rejuvenator. The results showed that the actual cohesion test approach, based on the evaluation of the indirect tensile strength (ITS), is not able to distinguish between RAP binders with stiff-brittle behaviour or good residual binding properties (despite the first is an unwanted condition while the second is a desired condition, both of them determine an increase in ITS). Differently, the Cracking Tolerance Index ( $${\rm{CT}}_{\rm{Index}}$$ ) defined by ASTM D8225-19 can emphasize the RAP bitumen ductility and highlight any residual binding and adhesive properties. For this reason, a RILEM cohesion test improvement is proposed by including the $${\rm{CT}}_{\rm{Index}}$$ calculation in the analysis.

These recommendations are based on the results of a round robin test organised by the RILEM technical committee TC 237-SIB "Testing and characterization of sustainable innovative bituminous materials and systems". The Task Group 1 (TG1) focused on binder testing. The aim of the TG1 was to further understand the fundamental mechanism of water interaction in asphalt mixture, and to review the various test methods available to evaluate the affinity of bituminous binders to aggregate surfaces. A total of 13 laboratories participated, running different test methods. Three bituminous binders and four aggregate types were selected for testing. These recommendations focus on the main aspects related to testing procedure, measurement and presentation of results. While some qualitative trends are observed, there is still a wide scattering in results both within the same test method and between test methods. This is not only related to a visual interpretation of the degree of bitumen coverage, but also theoretical and numerical analyses of test results. The overall recommendation is to consider the results within qualitative classes.

There has been a long partnership in the materials science of building materials between the National Institute of Standards and Technology (NIST) in the United States and the International Union of Laboratories and Experts in Construction Materials, Systems and Structures (RILEM). This paper discusses on the technical contributions NIST has made to RILEM, focusing on the articles published in Materials and Structures, whose 50-year anniversary is being celebrated in this issue. Since 1968, NIST has had a name change and a building materials division was formed, merged, and renamed since the 1970s, while RILEM has stayed constant in its name and organization, although its technical committee structure is purposely fluid. Many NIST personnel have contributed to the partnership between RILEM and NIST in more than one material type. This overview briefly covers these areas.

This paper summarizes the test recommendations for selected non-destructive testing (NDT) techniques as developed by members of the RILEM Technical Committee AST 215 "In situ assessment of structural timber". The recommendations cover visual inspection, moisture content determination, species identification, digital radioscopy, and ground penetrating radar. The paper includes a matrix of common NDT to assess structural timber. The discussion of each technique is intended to provide users with sufficient information to understand the theoretical basis, typical equipment set up, and basic capabilities and limitations.

The recommendations presented in this publication are inspired by the State of the Art Report edited by the RILEM Technical Committee TC 193 RLS Bonded cement-based material overlays for the repair, the lining or the strengthening of slabs and pavements. The objective is to lay out all the practical aspects to be considered in the design of concrete overlays: bonded concrete overlay process, assessment of the existing structure, surface preparation, overlay materials, design methods, construction procedure and quality control/assurance system, and maintenance.

Rutting is one of the main failure modes in pavement structures subjected to mechanical loading. Wheel Tracking Testers (WTT) devices used to evaluate the rutting performance of bituminous mixtures were investigated by Working Group 3 (WG3) “Mechanical Tests for Bituminous Materials”, of the RILEM ATB Technical Committee 206. Three different bituminous layer systems (A, B and C) currently used in road construction were compared to evaluate the abilities of “small” and “large” WTT devices to quantify road materials rutting performance. The tested specimens were cut from large slabs extracted from the onsite pavement structures. Seven laboratories located in seven different countries, were involved in the testing program. Results show that the mean rate of rutting for “small” WTT devices is faster than for “large” WTT devices. Systems A and C show equivalent performance and can be considered good in terms of the European Standard’s requirement. Results from system B indicate poor performance and it does not comply with the specifications of the standard. Nevertheless, a visual evaluation of the rutting showed a very good performance on the road for systems A and B and no apparent difference could be noted between these two systems.

Because of the different mix design in comparison with traditional concrete and the absence of vibration, different durability characteristics might be expected for self-compacting concrete. The state- of-the-art report, prepared by RILEM Technical Committee TC 205-DSC focuses on the Durability of SCC, by first gathering the available information concerning pore structure, air-void system and trans- port mechanisms. The available durability results are studied and summarised keeping in mind the funda- mental mechanisms and driving forces. All relevant durability issues are considered, like carbonation, chloride penetration, frost resistance, ASR, sulphate attack, thaumasite formation, fire resistance, etc... It is not the intention to give a review on these durability aspects for concrete in general. The aim however is to point at the specifics related to the use of SCC, e.g. due to the addition of a large amount of limestone filler, etc... This paper summarizes the main conclusions of the State-of-the-Art Report.

[EN]The present paper gives part of the results of a Round Robin Test on chloride analysis in concrete, carried out by the Technical Committee TC 178-TMC. In this RRT, the analysis of total chloride, free chloride and the colourimetric determination of the front of chlorides in concrete have been tested. This paper reports the results corresponding to total chloride content. Water soluble chloride and colourimetric front are reported respectively in Parts II and III of the paper. A total of 30 laboratories around the world have participated in this RRT, and a total determination of 64 different analyses on triplicate specimens have been carried out. The procedure for the analysis of total chloride has been divided into two steps: extraction and analysis, discriminating the relability of the procedure followed in each of them. Two different methods of extraction of total chloride from the solid sample (A1 and A2) as well as six different forms of analysing the resulting liquids (C1 to C6) have been tested. It was also decided that other methods could also be used to the choice of each laboratory, as “other methods” (A3 and C7 for extraction and analysis respectively). (The complete recipes of these methods can be found in Annex 1 of the paper.) The statistical treatment of the data has been carried out according to the International Standard ISO 5725-1981 (F) for the determination of the reliability of testing methods: “Determination of the repeatability and reproducibility by Round Robin tests”. As a final result the methods of extraction and analysis recommended for total chlorides have been the following: C1-C1, A2-C4*, A2-C7, A3-C4* and A3-C7., [FR]Cet article donne une partie des résultats d'un essai interlaboratoire réalisé lors de l'analyse du chlorure dans les bétons. Cet essai interlaboratoire a éte effectué par la Commission Technique TC 178-TMC. Dans cet essai, ont été testées, l'analyse totale des chlorures, des chlorures libres, ainsi que la détermination colorimétrique du front des chlorures dans le béton. Cet article rapporte les résultats qui correspondent au contenu total des chlorures. Les chlorures solubles dans l'eau et le front de colorimétrie sont reportés dans les seconde et troisième parties de ce papier. Dans le monde entier, une trentaine de laboratoires ont participé à cet essai interlaboratoire, et 64 analyses différentes surdes échantillons en triple exemplaire ont été effectuées. Le processus pour l'analyse totale des chlorures a été divisé en deux étapes: extraction et analyse, détaillant pour chacune d'elles, la fiabilité des processus employés. Deux méthodes différentes d'extraction des chlorures totaux à partir des solides (A1 et A2) ont été testées, aussi bien que six formes différentes d'analyse des liquides (C1 à C6). Les laboratoires étaient libres de choisir d'utiliser “d'autres méthodes” (A3 et C7, respectivement, pour l'extraction et l'analyse). (La recette complète de ces méthodes est reportée dans l'annexe 1). Pour la détermination de la fiabilité des méthodes de test, le traitement statistique des données a été réalisé en accord avec la norme internationale ISO 5725-1981 (F): “Détermination de la répétabilité et de la reproductibilité par essais interlaboratoires”. Comme résultats finaux, les méthodes recommandées pour l'extraction et l'analyse du total des chlorures, sont les suivantes: C1-C1, A2-C4*, A2-C7, A3-C4* et A3-C7.

Report of an International Conference held by RILEM and organized by the CSIRO Division of Building. Construction and Engineering, Melbourne, and the Australian Concrete Repairs Association, Melbourne, in cooperation with RILEM Technical Committee TC 124 ‘Repair Strategies for Concrete Structures Damaged by Steel Corrosion’.

Le comportementin situ des constructions en beton permet de determiner leur etat et leur duree de service. Il est essentiel de recommander les methodes les meilleures et les plus economiques pour le diagnostic et la verification des defauts, deteriorations, reseaux de fissures, de la corrosion et d’autres caracteristiques du comportementin situ des constructions en beton de types et d’âges differents.

The recommendations presented in this publication are inspired by the State of the Art Report edited by the RILEM technical committee TC 193 RLS Bonded cement-based material overlays for the repair, the lining or the strengthening of slabs and pavements. The objective is to lay out all the practical aspects to be considered in the design of concrete overlays: bonded concrete overlay process, assessment of the existing structure, surface preparation, overlay materials, design methods, construction procedure and quality control/assurance (QC/QA) system, and maintenance.

On November 6-7, 1997, the Second International Symposium on Durability of Building Sealants was held at Garston, Watford, England. The symposium was organised by the British Building Research Establishment Ltd. (BRE) on behalf of RILEM Technical Committee 139-DBS. It brought together architects, engineers and scientists-researchers and practitioners. Their aim was to transfer new ideas, gained from both laboratory research and field studies, to the study of sealant durability and the development of high performance sealants. Thirty-nine attendees from Europe, USA, and Canada listened to thirteen papers (three additional papers were submitted for publication only). Lively discussions dudng the breaks and over British tea stimulated new ideas and initiated further research into the durability of building sealants. The focus of the symposium was on the following topics: building joint movement monitoring and development of suitable laboratory simulation rigs, effects of early joint movement on the performance of sealed joints, test methods for the assessment of the fatigue resistance of sealants and the tenacity of sealant adhesion, effects of degradation factors on the mechanical properties and the chemical composition of sealants, correlation of changes in sealant properties produced by laboratory ageing techniques and those observed in naturally weathered samples or under in-service conditions, prediction of the long-term performance from accelerated weathering, prediction of the service life of sealants. RILEM Technical Committee 139-DBS, "Durability of Building Sealants", was inaugurated in July 1991 and has set itself the following objectives: a) to review the present knowledge regarding the assessment of durability of sealants, b) to promote research in this field, and c) to make recommendations for suitable experimental research. In particular, one of the technical committee's goals is to collect experimental data on the natural and accelerated ageing of sealants and to attempt to correlate data obtained according to different ageing regimes, using physical performance and chemical analysis methods. While much progress has been made in

The objective of the workshop was to exchange information on progress in science and practical application in the title subject. RILEM TC 70-OMD was active in that field in 1983-87 and the workshop should help in deciding whether a new Technical Committee is to be established and what would be the possibilities of achieving a success in the form of publication of a State-ofthe-Art Report and/or RILEM Recommendations. The scope of the workshop covered various methods of computer-aided design of concrete and different approaches to the problem of material optimization as applied to concrete-like composites. All kinds of cement-based materials were included, with special attention to high-performance concrete and concretes satisfying various environmental requirements (application of waste materials as components, non-leachable concrete for special containers, etc.). Applied methods and bases of material design were also considered.

RILEM Technical Committee 50—Fracture Mechanics of Concrete, has put forward a proposal for a recommendation for the determination of the fracture energy GF of mortar and concrete. In connection with the above three comparative test series were arranged in order to collect information and experience regarding the proposed method. 14 laboratories from 9 countries were involved and about 700 beams were tested. This paper gives a condensed summary of the results.

The development in recent years with increasing air pollution, increasing need of energy saving and last not least the growing number of damage in old structures leads to a raising demand to calculate the durability of structures, too. The paper has been prepared by request of the RILEM Technical Committee 45-LTO to show that, in principle, it is possible to evolve a theory for predicting the service life of r.c. structures and to sketch a way how that could be achieved. A lot of necessary basic data can be found scattered in the literature. To collect these data will be the first step to take.