Susceptibility of selected aggregates from sedimentary rocks to alkali-aggregate reaction

The paper presents the results of investigations into the reactivity of domestic aggregates produced from selected sedimentary rocks, carried out using the new testing methods, consistent with the RILEM and ASTM methods, implemented by GDDKiA (Polish General Directorate for National Roads and Motorways) documents. The range of the investigations covered coarse crushed aggregates produced from limestone, dolomite, sandstone and greywacke rocks, potentially suitable for making strong and durable concrete. No reactive forms of quartz were found in the mineralogical composition of the limestone aggregates and the dolomite aggregates. Micro- and cryptocrystalline quartz occurred in the particles of the greywacke aggregates and the sandstone aggregates. On the basis of the expansion of mortar and concrete specimens the aggregates produced from the sedimentary rocks were classified into the reactivity categories: R0, R1 and R2. A sodium-potassium-calcium silicate gel, whose composition (consistent with that reported in the literature) was characteristic of the alkali-silica reaction products, was found. The investigations resulted in a consistent assessment of the reactivity of the aggregates.