Sponsors: American Concrete Institute, RILEM, Université de Sherbrooke, CRIB, Université Toulouse III, Lmdc Toulouse, Kruger Biomaterials, Euclid Chemical, Prodexim International inc., BASF Master Builders, ACAA Editor: Arezki Tagnit-Hamou In July 1983, the Canada Centre for Mineral and Energy Technology (CANMET) of Natural Resources Canada, in association with the American Concrete Institute (ACI) and the U.S. Army Corps of Engineers, sponsored a five-day international conference at Montebello, Quebec, Canada, on the use of fly ash, silica fume, slag and other mineral by-products in concrete. The conference brought together representatives from industry, academia, and government agencies to present the latest information on these materials and to explore new areas of needed research. Since then, eight other such conferences have taken place around the world (Madrid, Trondheim, Istanbul, Milwaukee, Bangkok, Madras, Las Vegas, and Warsaw). The 2007 Warsaw conference was the last in this series. In 2017, due to renewed interest in alternative and sustainable binders and supplementary cementitious materials, a new series was launched by Sherbrooke University (UdeS); ACI; and the International Union of Laboratories and Experts in Construction materials, Systems, and Structures (RILEM). They, in association with a number of other organizations in Canada, the United States, and the Caribbean, sponsored the 10th ACI/RILEM International Conference on Cementitious Materials and Alternative Binders for Sustainable Concrete (ICCM2017). The conference was held in Montréal, QB, Canada, from October 2 to 4, 2017. The conference proceedings, containing 50 refereed papers from more than 33 countries, were published as ACI SP-320. In 2021, UdeS, ACI, and RILEM, in association with Université de Toulouse and a number of other organizations in Canada, the United States, and Europe, sponsored the 11th ACI/RILEM International Conference on Cementitious Materials and Alternative Binders for Sustainable Concrete (ICCM2021). The conference was held online from June 7 to 10, 2021. The conference proceedings, containing 53 peer reviewed papers from more than 14 countries, were published as ACI SP-349. The purpose of this international conference was to present the latest scientific and technical information in the field of supplementary cementitious materials and novel binders for use in concrete. The new aspect of this conference was to highlight advances in the field of alternative and sustainable binders and supplementary cementitious materials, which are receiving increasing attention from the research community. To all those whose submissions could not be included in the conference proceedings, the Institute and the Conference Organizing Committee extend their appreciation for their interest and hard work. Thanks are extended to the members of the international scientific committee to review the papers. Without their dedicated effort, the proceedings could not have been published for distribution at the conference. The cooperation of the authors in accepting reviewers’ suggestions and revising their manuscripts accordingly is greatly appreciated. The assistance of Chantal Brien at the Université de Sherbrooke is gratefully acknowledged for the administrative work associated with the conference and for processing the manuscripts, both for the ACI proceedings and the supplementary volume. Arezki Tagnit Hamou, Editor Chairman, eleventh ACI/RILEM International Conference on Cementitious Materials and Alternative Binders for Sustainable Concrete (ICCM2021). Sherbrooke, Canada 2021

Strain-hardening geopolymer composite (SHGC) based on industrial wastes and by-products has emerged as a feasible alternative to strain-hardening cementitious composite (SHCC). Lately, a novel slag/fly ash-based SHGC with promising strain-hardening tensile performance and multiple cracking behavior has been successfully developed. However, its environmental impact with regards to its global warming potential and energy consumption remain to be evaluated.

This paper presents an evaluation and comparative study of the environmental impact factors of a newly developed slag/fly ash-based SHGC and three different types of conventional SHCC materials. The CO₂ equivalent global warming potential (GWP) and the embodied energy (EE) were calculated under a life cycle assessment scheme based on the product stage. SHGC has significant advantages in terms of the global warming potential (GWP) while maintaining comparable or lower embodied energy (EE) when compared with greener version of SHCC materials and typical SHCC material (ECC M45), respectively. It could be concluded that the newly developed slag/fly ash-based SHGC demonstrates a very promising LCA record while possessing excellent technical performance. Consequently, SHGC could serve as a promising alternative for SHCC materials with considerably lower environmental impact.

The development of a method to evaluate water penetration in concrete is beneficial for analyzing the durability of concrete structures since water in concrete affects the progress of degradations such as salt attack, carbonation, alkali silica reaction. However, water in concrete is generally detected by an embedded electric moisture sensor, it is difficult to obtain continuous spatial distribution about water diffusion. Water penetrated into concrete with a thickness of 5 cm was observed by neutron imaging using a room-size neutron source based on a compact accelerator and macroscopic analysis on water penetration was carried out. The results showed that the neutron transmittance corresponds to the water content and the moisture profile. Then transfer properties of water in concrete were obtained nondestructively and quantitatively. In addition, the relationship between the test results evaluating void structure and the water penetration resistance was considered. This report shows a new simple method to evaluate water penetration in concrete.

Since both the yield stress and bleeding originate from the network of interacting cement particles, their correlation seems to be possible. The purpose of this paper is to investigate the existence of this correlation by varying solid volume fraction of cement paste. The static yield stress measurements were carried out using a traditional rheological test, and bleeding was determined by turbidimetry measurements. It appears that the correlation between yield stress and bleeding depends strongly on the solid volume fraction.

Converter steel slag exhibits very low hydration activity compared to ordinary portland cement. To increase its reactivity, a mixture with metakaolin (Al2O3·2SiO2) was designed to increase the binding capacity. Metakaolin was used for its purity and high pozzolanic reactivity, owing to its high alumina and silica content. Two systems were prepared, metakaolin and portlandite as a reference, and the second system was composed of converter slag and metakaolin. Reactivity was assessed by measuring the heat release of the hydration reactions by isothermal calorimetry. Calorimetry results show the cumulative heat of converter slag increases when metakaolin is added. Furthermore, new hydration products were identified. Large area phase mapping based on SEM/EDX spectral imaging was done to investigate the reactions between the components.