Experience with experimental designs and performance assessment of cold asphalt mixtures – New type of pavement structure in the Czech Republic

摘要

Presently there is a definite focus in road construction on technologies, which allow reducingrnenergy demand during manufacturing and realization of pavement structures and equally minimizing cost severityrnof new structures within the development of road infrastructure. Stated presumptions try to make provision forrntechniques of cold asphalt mixtures based on bituminous emulsion applications. Generally cold asphalt mix is arncomposite material containing crushed natural aggregates and sand with corresponding grading and slow-settingrncationic emulsion, which is produced and can be applied in normal atmospheric temperature. In comparisonrnwith traditional hot mix asphalts there is no requirement for heating some of the mix components. In the CzechrnRepublic the technology of cold asphalt mixes laid by normal pavers is not presently used, therefore insufficientrnlaboratory and practical experience and data are available. As a starting point experience and vast sets of datarnabout cold recycling mixes can be used. Because of the absence of valid technical specifications and so far notrnapproved preliminary specification prepared within the tasks of Ministry of Transportation French experience,rnvalid standards and validated procedures have been used. Within the experimental activity done at the CzechrnTechnical University selected physical and mechanical properties as well as performance-based characteristicsrn(stiffness, resistance against permanent deformations or fatigue) are presented.At the same time the most suitablerncompaction method for test specimen preparation was assessed as well. So far gained results and experiencernare presented in this paper. The objective is to extend and specify more precisely technical parameters and theirrnrequirements in the national technical specifications.