The performance of road ironwork installations

The term 'road ironwork' is used to refer to covers that are placed over manholes, drainage gullies, water valves and similar installations in highways, which are common in urban areas, Highway engineers have to deal with a high incidence of premature failure in these installations, the total costs of which are estimated to be pound 207 million per year, These failures are Generally characterized by Gradual deterioration of the surrounding bituminous surfacing, associated with failure of the bedding material supporting the ironwork frame, The reasons for this high incidence of failure were investigated in a major project which involved experimental and theoretical research including site observations and full-scale trials as well as laboratory studies, The results led to the development of a specification for improved bedding material.