Quality control of cold asphalt mixtures

Quality control consists of both mixture and construction inspection. Sampling, testing, thickness and degree of compaction procedures are similar to those applied for hot asphalts. 

Mix samples are taken from either the delivery trucks or the paved layer before compaction. 

The determination of bitumen content and aggregate gradation is carried out with the same test methods as for hot asphalts after the water has been completely evaporated from the mixture. 

The degree of compaction determination may be carried out using the sand-cone method or by core extraction. Core extraction is preferred when layer thickness is also needed to be checked. However, coring takes place a few days after compaction, possibly even after 2-3 weeks, to be able to extract intact cores. 

Sampling of constituent materials is carried out in the central mixing plant or upon delivery of the materials on site. Aggregate testing procedures are the same as those for hot mixtures. Bitumen emulsion testing, as well as tests on the recovered bitumen, follows the requirements and test methods specified in the standard used. 

---