Uncracked joints in plain concrete pavements: causes, effects and possibilities of improvements

Abstract

Article Info AbstractKeywords: pavements concrete uncracked joints crack widthDuring the construction of Jointed Plain Concrete Pavements (JPCPs) in Chile, it was observed that joints remained uncracked. The objectives of this paper are to evaluate the effects of uncracked joints (UnCrJ) in JPCPs and to propose possible solutions or improvements to avoid or minimize this phenomenon. Considering low thermal amplitude as cause of UnCrJ, a rational-based, detailed and empirically validated model is used to predict UnCrJ and crack width. The modelled results are not only due to material changes but also to the location of the series of cracks in time in the JPCP system. The paper contributes with this rational approach, instead of an empirical-simplified one, to achieve the objectives. For the modelled conditions, the "as-built" slab length range is 8 m to 56 m instead of the 4 m designed one. Then, more curling, joint faulting, water infiltration in sealed joints and load transfer efficiency ≤ 70% are expected. The alternative solutions proposed are associated to innovations as short joints spacing, unsealed joints and saw-cuts up to 50% thickness made with thin blade (≤ 3mm), which was verified with new field evidence provided in the article.

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“…Besides the referenced studies, the presence of UnCrJ in real-world JPCPs has been reported by other authors such as Zollinger et al [20] and Pradena & Houben [21]. In particular, Pradena & Houben [21] identified in the field the presence of UnCrJ even when traditional technical specifications for the saw-cutting depth were fulfilled. In this case, the effective slab length is three times greater compared to the originally designed slab length, i.e 3L.…”