Mechanization of finishing of pneumatic-concrete tunnel linings, ensuring lower roughness

Autor: N. I. Zinevich, A. G. Min’kov, A. A. Pogrebinskii, A. S. Nikolaev
Rok vydání: 1978
Předmět:
Zdroj: Hydrotechnical Construction. 12:869-874
ISSN: 1570-1468
0018-8220
DOI: 10.1007/bf02322082
Popis: 1. The experiments established the feasibility of mechanical finishing of pneumatic concrete linings, ensuring a roughness coefficient of n=0.011–0.012 for the lining surface. 2. To reduce the roughness of a pneumatic concrete lining, it is advisable to use a sand covering layer (Gunite). 3. The application of pneumatic concrete (including the covering layer) on a previously constructed primary lining of prefabricated or cast-in-place concrete should be performed in an automatied regimen, which produces a pneumatic concrete surface satisfactorily meeting the design specifications and leads to minimum waste from the shaping operation, the waste even being eliminated in many cases. 4. It is recommended that, for pneumatic concrete surfaces, use be made of the “anklepf” method for wall chambers and of the milling cutter method for tunnel walls and roofs, employing in the installation the corresponding interchangeable equipment. 5. For application of pneumatic concrete in the automated regimen, it is necessary to continue to improve the existing machine designs or to develop new ones which will ensure a more uniform discharge of the material from the nozzle.
Databáze: OpenAIRE