In this paper, test results obtained from six trial sections, where improvements in construction control procedures involving a number of properties had successively been introduced, are analysed and discussed. Particular emphasis was given to the cost of these improvements and the resulting reductions in variabilities and in characteristic deflection values. The paper also provides some estimates of pavement `life' extensions based on the measured reductions in deflections and estimates of the degree of dependence of deflections on the underlying pavement and material properties. The results showed that significant reductions in characteristic deflections, which indicate substantial increases in pavement `life', can be achieved, at a small addition to the total cost of construction, when improvements in construction control procedures of one or more of the investigated properties, namely levels, moisture content, grading and compaction, are implemented. The results also showed that basecourse deflections were found to depend, to a large extent, on sub-base deflections and sub-base relative compaction while sub-base deflections largely depended on subgrade deflections. This finding suggests that similar compaction standards should be specified for all pavement layers. (A)
Abstract