Materials

At Hamburg, sand-cement stabilization (SCS) conseructed by the central-mixed (stationary plant) method is successfully used for frose-protection courses. The requirements applicable to these courses, which as a rule are 15 em thick, are based on those for cementbound sub-bases as laid down in the TVT regulations: degree of compaction ~98%,...

The principal criteria applicable to the mix design and the properties of lean concrete are: - splitting tensile strength in the region of 1.7 MFa and compressive strength in the region of 15 MPa at 28 days; - good erosion resistance; - lowest possible modulus of deformation; - possibility of...

Cement-bound sub-bases (CaSBs) are constructed ~ithout joints. During and after hardening, cracks may be formed in consequence of drying and/or cooling, even if the sub-base has noc yet been subjected co any traffic load. It would be desirable to have no cracks or only very fine ones (capable of eransmieting...

The curing compounds hitherto employed have not always been found satisfactory when applied to road concrete with superplasticizer, to concrete on small jobs, to concrete placed by slipforming and to cement-boundsurfacings. For this reason three new types of curing compound have been introduced, namely, compounds which - give good protection...

The engineering properties of a soil-cement mix are adversely influenced by any delay between mixing and compaction. This problem is more serious in hotter climates where the initial setting period is relatively short. As a consequence of this situation, the final product often fails to meet specification requirements. A laboratory...

Road concrete made with superplasticizers has successfully been used for about ten years now. Its special features with regard to mix composition and method of placing were reported in detail at the London symposium in 1982. This method of construction is increasingly being applied in Austria: - For the maintenance...