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| Cracked structure due to alkali-aggregate reaction (photo by M.A. Glinicki) |
IPPT PAN and the Institute of Ceramics and Building Materials (the project coordinator) have started research work in the programme "Development of Road Innovations" - R&D . This work is supported by the National Centre for Research and Development (NCBiR) and the General Directorate for National Roads and Motorways (Generalna Dyrekcja Dróg Krajowych i Austostrad GDDKiA).
The NCBiR and GDDKiA committed to joint financing of R&D projects that contribute to improving road safety, effective traffic management system and the development of optimal norms and standards of planning, design, technology, construction and operation of roads in Poland.
Project "THE ALKALINE REACTIVITY OF DOMESTIC AGGREGATES" is coordinated by the Institute of Ceramics and Building Materials (Krakow Branch).
The research team from IPPT PAN will work: prof. M. A. Glinicki, Ph.D., Dr. habil., Eng.; prof. A.M. Brandt, Ph.D., Dr. habil., Eng.; D. Jóźwiak-Niedźwiedzka, Ph.D., Dr. habil., Eng.; M. Dąbrowski, Ph.D.; K. Gibas, M.Sc.; A. Antolik, M.Sc.; M. Sobczak (Divisions Strain Fields, Department of Strength of Materials at IPPT PAN).
The objective of the research is to identify the susceptibility of minerals occurring in rock aggregates to chemical reaction with potassium and sodium hydroxides present in pore water of cementitious matrix in concrete. The alkali aggregate reaction (AAR) can cause internal expansion and cracking of material. As a result it may cause a severe damage to engineering structures and road pavements. Therefore the investigation is also practically oriented- it should result in formulation of criteria for reactivity evaluation and selection of aggregates that could be implemented in QA/AC of aggregate production in various regions of Poland. It is also expected that the technical guidelines for design of high durability concrete are developed, particularly tailored for damage prevention due to alkali aggregate reaction at relevant climatic environment and service loads. The implementation of practical results is intended in the highway administration, mining industry and building construction and road building companies.
The reactivity of aggregate is largely related to its geological origin and mineralogical composition; the main indicator of reactivity is the presence of amorphous silica, opal, trymidite, cristobalite, cryptocristalline and microcrystalline quartz. The research conducted in PPO division headed by prof. Glinicki is focused in identification of reactive minerals using microscopic and physical test methods and well as in experimental evaluation of mechanical damage induced by the use of mineral aggregates in cementitious matrices. Original test methods are being developed, particularly using digital image analysis and expansion measurements of specimens exposed to combined chemical, physical and mechanical loads.
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| Reactive quartz size in polymineral aggregate (photo by D. Jóźwiak-Niedźwiedzka) | Cracked aggregate, ASR gel around aggregate in cement matrix (photo by D. Jóźwiak-Niedźwiedzka) |