Crushed aggregates are used in the production of ready-mixed concrete, precast concrete elements and prestressed concrete. Since ancient times the Pantheon in Rome has served as a classical example of a concrete structure. The architects of this building used concretes with different densities to suit the respective structural requirements.
Thanks to its angular grain shape, broken stone achieves an excellent interlock within the concrete, and that helps concretes to achieve particularly impressive final strengths.
Quality chippings are grain sizes that satisfy enhanced specifications regarding shape of grain, oversize and undersize, mechanical resistance and freedom from contamination. Not every stone can fulfil the requirements of a quality chippings specification. Basalt-Actien-Gesellschaft produces quality chippings from various types of rock, including granite, diorite, gabbro, gneiss, quartzite, rhyolite, andesite, basalt, diabase, kuselite or greywacke. The range of quality chippings shows that a stone is not simply a stone!
Ready-mixed concrete suppliers have been using crushed rock fine aggregates successfully for a number of years. To meet these needs, Basalt AG developed a special fillers removal plant in which the dust fractions of the crushed rock fine aggregate are filtered out to such an extent that it is possible to produce a high-quality crushed rock fine aggregate that meets the demands of the ready-mixed concrete industry. Following initial scepticism on the part of customers, plus further measures to optimise the process, the use of crushed rock fine aggregate in ready-mixed concrete has now become accepted. Indeed, it delivers such worthwhile successes that it is often specified at tender stage: “. . . using at least 50% quality crushed rock fine aggregate . . .”
For many years Deutsche Bahn AG and numerous contractors involved in permanent way works have been putting their faith in Basalt-Actien-Gesellschaft as a competent partner and supplier of high-quality railway ballast. Just-in-time deliveries in this industry, like many others, have become the norm, and are now standard practice in the Basalt Group. The large network of plants allows Basalt-Actien-Gesellschaft to respond flexibly to customers' needs, and the proximity to those customers ensures that adequate supplies are available at all times. These advantages simplify planning and coordination for our customers, even in the case of major construction projects.
Wherever roads, railways or structures need a firm foundation, graded aggregates, prepared to optimised grading curves and compacted in situ, can achieve the necessary load-bearing capacity. The specification regarding load-carrying capacity, water permeability or frost resistance determines the best type of aggregate for macadam, sub-bases, etc. Less critical applications can utilise aggregates such as stony soil, screenings, backfill material or ungraded blasted rock, which are not covered by quality-control measures.
Basalt AG was originally founded to supply stone for coastal protection projects in the Netherlands. Rocks of various sizes and weights (up to several tonnes) are still supplied today for strengthening banks and dykes. Hard rocks with particularly high density, strength and frost resistance are ideal for such purposes.
The German public became all too aware of the importance of flood prevention schemes again in recent years following the severe flooding along the Elbe, Mulde and Oder rivers.
