Daily and Seasonal Variation of Several Parameters Based on the Measured Deflection at the Edges of Different Types of Semi-rigid Pavements Transverse Cracks

There are around 30% semi-rigid pavements in the National Spanish Roads Network, being a composition of bituminous layers over cement treated layers. Those with more than 20 years in service were constructed with a high percentage of cement. As a result, thermal transverse cracks were reflected on the wearing course, which have to be sealed and reinforced periodically. This research is focused on transverse cracks edges daily and seasonal variation of Load Transfer (LT, %), Relative Deflection (RD, micrometer/micrometer) and Maximum Deflection (MD, micrometer), of four types of situations: thin cracks (width < 5 mm); wide cracks (width ≥ 5 mm); block cracks and fatigue cracks on the wheel-paths. For this purpose, eight sections of roads were chosen from thermal zones hot in summer and little rainy but cold in winter. The findings of this study have been the quantification of the transverse cracks pavement structural state in two scenarios referred to as winter and summer conditions. Firstly, it was proved that the before mentioned structural parameters correlated with temperature. Secondly, these parameters' daily and seasonal variations were defined. The main findings of this research are: (1) MD in semi-rigid pavements is even less than 200 micrometer after more than 20 years in service. Thus, LT and RD turn out to be the main structural parameters to evaluate pavement bearing capacity close to thermal transverse cracks; (2) LT rises with temperature reaching 100% whereas RD decreases reaching almost 1 micrometer/micrometer, as well as, MD goes down up to the temperature turning point in which the bituminous layers influence is higher; (3) After more than 20 years in service, semi-rigid pavement road stretches could show good pavement structural state (that is, LT > 80%) measuring at any time in summer condition (average temperature 5 cm below the surface ≥ 20 °C); (4) Crack sides MD measured with pavement temperature close to 20 °C (reference temperature for Spanish standardized deflections) in winter condition (average temperature 5 cm below the surface < 20 °C), could also show a good pavement structural state, MD < 300 micrometer; (5) If the worst structural pavement state needs to be evaluated, deflections should be measured on the front side cracks except for block shape cracks in winter condition and thinner cracks in both conditions; (6) Wide cracks LT experiences the greatest daily variation range among all crack types, from more than 20% to more than 30% in winter condition and thin cracks unseat them in summer condition with a daily variation range from almost 10% to less than 20%; and (7) Besides, wide cracks RD daily variation is the highest among all crack types in both conditions, ranging from a decrease of more than 0.30 micrometer/micrometer to more than 0.60 micrometer/micrometer in winter condition and half this range of values in summer condition.

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  • English

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  • Accession Number: 01607934
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 29 2016 8:33AM