International Concrete Abstracts Portal

Differential curing occurs when variations in curing methods, materials, or site conditions result in inconsistent moisture loss, hydration, or temperature across a concrete floor slab. This inconsistency can produce significant performance and appearance issues in both plain and polished concrete floors. This article highlights the causes and effects of differential curing, and best practices to achieve uniform curing.

The first international symposium on “Advances in Concrete Technology” was sponsored jointly by Canada Centre for Mineral and Energy Technology (CANMET), the American Concrete Institute (ACI), and several other international organizations in Athens, Greece, in May 1992. Dr. Mohan Malholtra served as the chairman of the symposium. In June 1995, CANMET, in association with ACI and various professional organizations from the United States and Canada, sponsored the Second CANMET/ACI Symposium on Advances in Concrete Technology in Las Vegas, NV, USA. This event focused on high-performance normalweight and lightweight concretes, with the proceedings formally published as ACI SP-154. The Third CANMET/ACI Symposium on Advances in Concrete Technology was held in Auckland, New Zealand, in August 1997, sponsored by CANMET, ACI, and partner organizations from Canada and New Zealand. The symposium brought together industry, university, and government representatives to explore new areas of research, resulting in the publication of 33 refereed papers from 15 countries as ACI SP-171. In June 1998, the Fourth CANMET/ACI Conference on Advances in Concrete Technology took place in Tokushima, Japan, sponsored by CANMET, ACI, the Japan Concrete Institute (JCI), and several organizations from Japan and Canada. From more than 80 submissions across 20 countries, 61 refereed papers were published as ACI SP-179, while more than 30 additional technical contributions were presented. The Fifth CANMET/ACI Conference on Advances in Concrete Technology was held in Singapore in July and August 2001, under the sponsorship of CANMET, ACI, and multiple Singaporean organizations. This milestone event saw over 100 papers from 25 countries, leading to the publication of 46 refereed papers as ACI SP-200, and more than 25 additional papers were presented. In June 2003, the Sixth CANMET/ACI Conference on Advances in Concrete Technology was held in Bucharest, Romania, with sponsorship by CANMET, ACI, and several Romanian organizations. During this event, more than 40 technical papers were distributed to participants as received, though no formal ACI Special Publication was issued for this symposium. The Seventh CANMET/ACI Conference on Advances in Concrete Technology was held in May 2004 in Las Vegas, USA, sponsored by CANMET, ACI, and several U.S. organizations. The technical program resulted in 17 refereed papers from more than 10 countries published as ACI SP-222. In May 2006, CANMET, ACI, and organizations from Canada and the United States sponsored the Eighth CANMET/ACI Conference on Advances in Concrete Technology in Montreal, QC, Canada. The proceedings, consisting of 17 refereed papers, were published as ACI SP-235, supplemented by more than 30 additional technical papers distributed at the venue. The Ninth CANMET/ACI Conference on Advances in Concrete Technology was conducted in Warsaw, Poland, in May 2007, under the sponsorship of CANMET, ACI, and partners from Canada, Europe, and the United States. The final proceedings included 10 refereed papers published as ACI SP-243 along with more than 20 supplementary papers. Sponsored by ACI in association with several organizations from Canada, Europe, and the United States, the Tenth ACI Conference on Advances in Concrete Technology took place in Seville, Spain, in October 2009. This event produced 20 refereed papers published as ACI SP-261, while more than 20 additional papers were released in a supplementary volume. In May 2010, the Committee for the Organization of International Conferences (COIC) (formerly CANMET/ACI Conferences) and the Chinese Ceramics Society (CCS) sponsored the Eleventh International Conference on Advances in Concrete Technology and Sustainability Issues in Jinan, China. This gathering featured the presentation of more than 40 papers, with the formal proceedings published by the CCS, Beijing, China. The Twelfth International Conference on Advances in Concrete Technology and Sustainability Issues was held in Prague, Czech Republic, in October 2012, sponsored by COIC and ACI with a new focus on sustainability issues. The resulting volume, ACI SP-288, featured more than 30 refereed papers, while an additional 40 papers were included in a supplementary volume. In July 2015, COIC and ACI sponsored the Thirteenth International Conference on Advances in Concrete Technology and Sustainability Issues in Ottawa, ON, Canada. This technical exchange yielded 28 refereed papers published as ACI SP-303, alongside with more than 40 other papers presented in a supplementary papers volume. The Fourteenth International Conference on Recent Advances in Concrete Technology and Sustainability Issues was sponsored by the CCS, the China Academy of Building Research (CABR), and COIC in Beijing, China, in October 2018. The technical output included 19 refereed papers published as ACI SP-330, with more than 52 additional papers featured in the supplementary volume. After a postponement due to the COVID-19 pandemic, the Fifteenth International Conference on Recent Advances in Concrete Technology and Sustainability Issues was sponsored by the ACI Italy Chapter and the University of Bergamo in Milan, Italy, in July 2022. This event focused on decarbonization and alternative binders, resulting in 44 refereed papers published as ACI SP-355, and approximately 20 papers were published in the supplementary volume. The Sixteenth International Conference on Recent Advances in Concrete Technology and Sustainability Issues is being held in Munich, Germany, from 8 – 10 July, 2026. This prestigious gathering is hosted by the Technical University of Munich (TUM) with the support of ACI. The conference continues its long-standing mission of advancing concrete science, with a sharp focus on the industry’s most pressing challenge: the transition of the cement industry towards decarbonization and the implementation of new technologies for long-term sustainability. 19 refereed papers for this conference are published herein as an ACI Special Publication, focusing on topics including: use of supplementary cementitious materials such as alkali-activated slag, calcined clay, red mud and other industrial wastes; pozzolanic reactivity of SCMs; long-term investigation on cement and cement additives; reduction on CO2 emission, etc. Additionally, more than 50 other papers will be presented at this event, most of them available in a Supplemental Papers Volume. The organizing committee expresses its profound gratitude to the authors, reviewers, and partner organizations whose dedication continues to drive the evolution of concrete technology toward a more sustainable future. Special thanks are also given to the American Concrete Institute for the publication of the proceedings. The Editor Prof. Dr. Johann Plank

This article discusses the development and benefits of CEM II/C-M type low-carbon cements, highlighting their future role in reducing CO₂ emissions within the cement industry. It outlines key production strategies, including the use of quality improvers to enhance early strength and overall cement performance. Comprehensive laboratory testing assessed the durability of CEM II/C-M cements, revealing low shrinkage and robust resistance to water ingress and aggressive chemical agents such as chlorides. Additionally, these cements demonstrated adequate freeze-thaw and carbonation resistance, with performance comparable to standard cements. These findings underscore the potential of CEM II/C-M cements to meet the demands of sustainable construction while maintaining high performance standards. The article also showcases examples of industrial production and the application of these cements in concrete.

Supplementary cementitious materials (SCM) are promising alternatives for the reduction of CO₂ emissions in the cement industry. Despite extensive research, their adoption, using Germany as an example, remains low due to potential disruption in manufacturing processes and standardization issues. Furthermore, the precursor output rate of e. g., fly ash and ground granulated blast furnace slag (GGBFS) is limited not only due to general cement substitution but for shortages in their respective industries. As a result, SCMs may only serve as a viable alternative binder in niche applications, such as concrete maintenance and repair. Additionally, the use of dry activators such as Na₂CO₃ facilitates conventional production methods.

This paper discusses results of sodium carbonate-activated slag mortars that were applied to concrete reference plates (A3-type as described in “Technische Regel Instandhaltung von Betonbauwerken,” eng. technical guideline for maintenance of concrete structures). The performance of alkali-activated slag (AAS) mortars was evaluated in terms of shrinkage behavior, compressive, flexural, and adhesive strength after dry thermal cycling and thunder-shower cycling. Interestingly, the results showed enhanced strength after exposure to these experimental conditions in comparison to ambient temperature curing. This highlights the critical role of proper curing, as AAS mortars are highly susceptible to increased shrinkage when not exposed to sufficient moisture.

The previous results show that AAS mortars - even without optimization - meet the required properties for structural repair class “R3” as defined in DIN EN 1504-3, promoting SCMs as promising alternative binders for these practical use cases.

An innovative automated experimental system is proposed for precise evaluation of cement dispersant performance. The system enables comprehensive rheological measurements of 230 mL mortar samples without human intervention, overcoming limitations of traditional manual testing methods. Our automated experiment platform incorporates a continuous-processing approach with precise control over sample preparation, including automated water and dispersant dosing via peristaltic pumps, programmed mixing sequences, and systematic rheological measurements through a specialized vane rotor system. The experimental sequence consists of dry mixing, water incorporation, final high-speed mixing, and rheological measurements at controlled rotational speeds, all executed automatically with consistent timing and conditions. This approach reduces the labor-intensive nature of conventional testing while enabling the collection of substantially more data points for comprehensive analysis. The system allows for finer increments in dispersant dosage evaluation and eliminates variations associated with manual handling, thereby providing more reliable and reproducible results. Combined with data science techniques including principal component analysis and observation-informed learning, this automated framework establishes a new paradigm for cement-based materials characterization and quality assessment, suitable for both research and industrial applications in concrete technology.