The article presents various systems of sample preparation for testing of compressive strength of hydraulic road binders, encompassing the manner of sample formation and curing, as well as determination of mixture composition (mortar or paste) and water content. Two methods of sample curing were taken into account: in water bath and in humid air. Research was performed on chosen hydraulic road binders with varying content of calcareous and siliceous constituents. The tested binders were also characterized in terms of proportion of material retained on 45 μm sieve. The obtained results confirmed the need for distinction between various systems of specimen preparation in road binder compressive strength testing in order to appropriately classify the binders according to their performance and functions in road pavements or improved subgrades.
PL
W artykule przedstawiono systemy przygotowania próbek do badania wytrzymałości na ściskanie spoiw drogowych, obejmujące wykonanie i dojrzewanie próbek. Wykonanie obejmuje zagadnienie składu mieszanki (zaprawa lub zaczyn) wraz z doborem ilości wody. W zakresie dojrzewania próbek wyróżniono dwa sposoby: w kąpieli wodnej i w wilgotnym powietrzu. Badania przeprowadzono dla przykładowych hydraulicznych spoiw drogowych o różnej zawartości składników krzemionkowych i wapiennych. Do opisu badanych spoiw wykorzystano również badania pozostałości na sicie 45 μm. Wyniki badań potwierdziły potrzebę wyróżnienia w badaniach wytrzymałości na ściskanie spoiw drogowych różnych systemów przygotowania próbek na cele klasyfikacji tych spoiw pod względem ich działania i funkcji w konstrukcji nawierzchni drogowej lub ulepszonym podłożu.
The study deals with granite aggregates of various fractions, originating from Polish and foreign deposits, used for concrete in communication engineering. The article discusses the issue of cement reaction with granite aggregate during exposure under specific climatic conditions and how it affects the durability of concrete structures. Granite aggregates were used to prepare concrete beams that were subjected to research analysis according to PN-EN and ASTM. Particular attention was paid to processes occurring between reactive minerals (including chalcedony, opal, tridimite, and highly-strained quartz) and the alkalis present in cement. Research methods and results of alkaline reactivity tests on granite aggregate trabecula are presented. They were carried out at the Concre¬te and Aggregate Division of the Road and Bridge Research Institute - Wroclaw Branch. The paper also presents the analysis of research results and criteria to which potentially reactive aggregates are subject.
Coaly shale is a full-fledged aggregate for road construction, which can be obtained through proper control and processing, meeting the performance characteristics for the application in the construction of embankments. In Poland, from current pro¬duction and resources at landfills, coaly shale with a pyrite content above 1% is a great potential for road construction. It requires adaptation, including on eliminating the possibility of bacteria decomposing this pyrite or its neutralization using limestone materials. At the same time, taking into account the weaknesses of coaly shale landfills (in terms of self-ignition and decomposition), the type of coaly shale and pyrite raw material can be identified as ways of using aggregates from these raw materials for the construction of embankments in the appropriate construction technology.
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