Paper by SCHMIDT WESTERMANN BOHLMANN from ISCR 8th 1998 Lisbon Portugal
At the Research, Development and Consulting Department of the Heidelberger Zement AG, a research project has been carried out on the influence of the composition and compaction on the properties of roller-compacted concrete. At a low compaction rate of only 96% of the modified proctor density, roller compacted concrete containing a sufficiently high amount of cement of at least 240 kg/m 3 achieves compressive strengths of at least 40 N/mm 2 . This is the minimum required for sub-base layers in Germany. The resistance of roller compacted concrete to withstand frost exceeds the limit set for an adequate frost-thaw resistance of commercial concrete, regardless of the aggregate admixed and its cement content. The roller compacted concrete tested achieved adequate resistance to frost and de-icing salt even without air entraining agents being added if the concrete is based on the relatively high cement content of 270 kg/rn 3. By using air entraining agents, a sufficient degree of resistance to frost and de-icing salt could invariably be obtained iiidepeiideiil of the ceiiieiil eoiiteiil beiiig used.