New Material Treatment Technologies in Management of the Effect of Seasonal Variations

Resumo

In the recent years, it has been considered more to use lower quality aggregates in road construction. This has become necessary mostly due to smaller supply of good quality materials available within a reasonable transportation distance and higher transportation costs. Nontraditional stabilisers have been marketed as economical and promising to improve the properties of poor quality materials. In the regions with long frost periods, such as S candinavia, open-graded aggregates containing a small amount of fines have been used in road construction in order to prevent frost heave. As fines content increases, the moisture susceptibility of aggregate becomes greater, leading to problems with bearing capacity in spring when frost thaws. The research was done to find out if non-traditional stabilisers would provide a toolbox for decreasing the moisture susceptibility of coarse-grained aggregates having, except for spring-time frost thawing, a sufficiently good bearing capacity. Polymeric and ionic stabilisers and resins have been tested. This paper presents the effects of the stabilisers on four different aggregates. The laboratory research consists mainly of Tube Suction tests. The literature studies and test results indicate that ionic and enzymatic stabilisers can hardly be used for decreasing moisture susceptibility in aggregates having a fines content of less than 15%. The tests showed that polymeric stabilisers and resins were the most promising stabilisers. It must be noted that the same stabiliser might act in a different way from one aggregate to another. Therefore it should always be checked whether the stabiliser is
applicable in connection with the aggregate in question.