TY - JOUR N2 - Proper values of physical and mechanical properties and their homogeneity are one of major requirements deciding about technological suitability of the rocks quarried to manufacturing aggregates. These properties depend on the natural features of a rock, its mineral composition, texture and structure. The characteristic of aggregates and the technical requirements they must meet are normalized in adequate standards that describe the procedures of conducting particular determinations and the methods of interpreting their results. In the basaltoids (usually called basalts) of selected deposits of Lower Silesia that represent different intrusive forms, five textural varieties have been distinguished: aphanitic, aphanitic-porphyritic, porphyritic-aphanitic, porphyritic-nodular and nodular-porphyritic. The petrography and essential physical and mechanical properties of these varieties have been described in Tables 1 and 2, respectively. The highest technical parameters have the aphanitic and aphanitic-porphyritic rock varieties. They result mainly from the textures of these rocks and their insignificant weathering, and to a lesser degree from their mineral composition. The resistance to wear (micro-Deval) and the resistance to fragmentation (Los Angeles) of the aggregates that represent the grain fraction 10-14 mm of the five varieties of basaltoids and the rock composites were determined according to the standards PN-EN 12620: 2008 and PN-EN 13043: 2004. Of the aggregates produced from the five major varieties, only those made of the nodular-porphyritic basaltoids have the properties of lower categories, whereas the remaining four are the materials of very high quality. Additionally, it has been shown that by combining various basaltoid types it is possible to produce composite aggregates with the variable qualities belonging to the categories LA and MDE (Tab. 3). The effect of rock petrography on the differentiation of the parameters of aggregates depending on the grain fraction of the products (Fig. 1, Tab. 4) is the lowest in the case of the aggregates produced from the homogenous and not weathered rock. In contrast, the range of variability of the parameters is higher if the starting material to produce aggregates is composed of several textural varieties and shows signs of weathering as well. The possibility of delineation of the areas occupied in the deposit by basaltoids with specific textural varieties creates the conditions of determining the rock zones, from which the aggregates of the predicted quality may be produced. This quality may be controlled and partly changed to the user needs by producing aggregates from the specially prepared rock mixtures (i.e. the charge to crushers) with specified proportions of the basaltoid varieties. L1 - http://www.czasopisma.pan.pl/Content/119225/PDF-MASTER/rembis.pdf L2 - http://www.czasopisma.pan.pl/Content/119225 PY - 2011 IS - No 3 EP - 49 KW - Lower Silesia KW - petrography of basaltoids KW - categories of aggregates A1 - Rembiś, Marek PB - Komitet Zrównoważonej Gospodarki Surowcami Mineralnymi PAN PB - Instytut Gospodarki Surowcami Mineralnymi i Energią PAN DA - 2011 T1 - Mineral and textural variability of selected Lower Silesian basaltoids and its role in controlling the physical and mechanical properties of the agregates produced SP - 29 UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/119225 T2 - Gospodarka Surowcami Mineralnymi - Mineral Resources Management ER -