In this study, tests are being carried out on cement-grouted macadam as a roadbase. The aim is both to test an improved production technique and to follow up the final results for two test sections built in 1988. In both tests the coarse, relatively uniform macadam, has been laid with a macadam spreader. The liquid cement-mortar has been spread with a converted asphalt paver. During the tests, it has been found that the best results are achieved when the macadam is laid with a macadam spreader instead of a grader. When using a macadam spreader, it is important that the macadam maintains the specified fraction limits. Excessively large stones easily block the feed slit in the spreader. Construction traffic should be avoided spreader. Construction traffic should be avoided on unbound macadam since rutting is likely to occur in the somewhat unstable surface. By using a concrete pump to fill the mortar spreader's trough, construction traffic and consequent rutting can be avoided. (A)
Abstract