National Institute for Transport and Road Research
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Item Rapid field test for carbonation of lime or cement treated materials(1984-04) Netterberg, FA rapid field test for carbonation of lime, lime-slag, lime-pfa, cement, cement-pfa or cement-slag stabilized pavement material is described. The treated material is simply sprayed with phenolphthalein, phenol red and dilute hydrochloric acid solutions. If the untreated material does not contain carbonate (i.e., fails to effervesce with hydrochloric acid) and the treated material does not turn red with phenolphthalein, but turns red with phenol red and effervesces with hydrochloric acid, the material is carbonated. If the untreated material does contain carbonate (i.e., effervesces with hydrochloric acid and probably turns red with phenol red) and the treated material does not turn red with phenolphthalein, the material is probably carbonated. The phenolphthalein test can also be used to test for the presence or absence of lime or cement in a frehly treated material, but not for the amount present.Item Calcrete in road construction - Bulletin(1971-09) Netterberg, FThe composition, distribution, origin, and age of South African calcretes are briefly reviewed and a simple classification suitable for engineering use described. Methods of searching for economic calcrete deposits and of testing calcretes for roadmaking are considered and it is concluded that special methods of locating these must be used and that precautions must be taken during testing if the best results are to be achieved. The engineering properties of calcretes and specifications for calcrete roads are dealt with in some detail. Depending on their stage of development, these materials range in properties from those of an almost useless powder to those of rock, and this and their unusual composition and mode of formation cause them to exhibit unusual and often beneficial properties. Depending on the actual stage of development reached, calcretes can be suitable and have been used for all classes of road material, including surfacing chips, base, subbase, gravel road wearing courses and concrete aggregate. Some of the usual soi I constants and grading requirements can be considerably relaxed when these materials are employed and significant economic benefit can result.Item Calcrete in road construction- first draft(1969-01) Netterberg, FThe composition, distribution, origin and age of South African calcrete are briefly reviewed and a simple classification suitable for engineering use described. Methods of searching for economic calcrete deposits and of testing calcretes for roadmarking are considered and it is concluded that special methods of locating these must be used and that precautions must be taken during testing it the best results are to be achieved. The engineering properties of calcretes and specifications for calcrete roads are dealt with in some detail.