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Sewer manholes are essential elements of gravity sewerage systems. The wide
range of market offers includes both plastic and concrete sewer manholes. In order
to fulfil its function and make its long-standing, proper exploitation available,
manholes should be made of high quality materials. The apparent ease of producing
sewerage manholes prefabricated elements and low quality materials used by some
producers caused that concrete manholes seem to be impermanent. However, the
technology of prefabrication and principles of concrete manholes realizations are
continuously improved. Nowadays, the building of concrete manholes which
enables a long-time proper exploitation is possible and often applied.
This paper presents results of an evaluation and analysis of the condition of 41
concrete exploited sewerage manholes of gravity sanitary systems and gravity storm
water drainage systems. Manholes were located in 13 different testing points in
5 voivodeships in Poland. The exploitation time of examined sewer manholes
varied from 1 to over 11 years. During the test, the general condition of manholes
was valuated as well as the condition of manhole base units. Information about
every manhole was supplemented with the manhole’s exploitation time,
localization, system type and manhole base unit producing technology. As
additional, in selected cases also examinations of sewage pH and concrete pH were
executed. The sewage and concrete pH was examined by the Rainbow-Test method
indicator. Basing on executed analysis, a dependence rule between technical
condition of a manholes and their time of exploitation and producing technology
were tried to be defined.
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