Load Transfer-Crack Width Relation of Non-Dowelled Jointed Plain Concrete Short Slabs

Abstract

Abstract. Non-dowelled short slabs are a cost-effective innovation of jointed plain concrete pavements. The development of this innovation has been concentrated in their structural performance. Still there is a lack of specific studies of the relation load transfer -crack width, being the crack width at joint the direct cause of the aggregate interlock. Considering that their provision of load transfer relies on aggregate interlock, the objective of the present article is to develop the relationship between the load transfer by aggregate interlock and its direct cause (the crack width) specifically for innovative nondowelled short concrete slabs pavements. For that, the analysis includes a validated nonlinear aggregate interlock model incorporated in a 3D Finite Element program, laboratory results, and field measurements performed as part of the present investigation. The results show that due to the small crack widths, the short slabs are able to provide adequate load transfer (not less than 70%) even without dowels bars. Indeed, in this case, the load transfer relies on aggregate interlock and the results of the Faultimeter (residual value more than 0) have confirmed this interlocking for crack widths at joints not more than 1.2 mm, which are typical values in short slabs when the joints are activated. For that, the Early Entry saw cutting method needs to be modified or applied as a complementary method to perform the joints. Although in short concrete slabs pavements the provision of load transfer is already guaranteed by the small crack widths at joints, the application of high-quality coarse aggregates provides even higher load transfer.

Laboratory Characterization of The Load Transfer-Crack Width Relation for Innovative Short Concrete Slabs Pavements

“…The objective of the present article is to characterise in the laboratory the LTE-CW relation for innovative short concrete slabs pavements. Although the characterisation is general, in the present article the laboratory results obtained using the same aggregates, which the Chilean test section of short slabs reported by Pradena & Houben (2018), are presented to give a better explanation to the singular behaviour observed in the field.…”

“…According to the characterisation of aggregates made for Chile, the region of origin of the aggregates (Metropolitan Region) presents LA values between 12% to 14.9% (Pradena & Houben, 2018). These LA values are considerably below the 35% maximum allowed in the specifications of the Chilean Highway Manual (Dirección de Vialidad de Chile, 2018) and the 40% allowed by the FP-14 Standard Specifications for Construction of Roads and Bridges on Federal Highway Projects.…”

“…In other words, the LTE values obtained from static loads are more conservative than the ones from dynamic loads. Since the Chilean aggregates are also high-quality (Pradena & Houben, 2018), and the LTE values from static loads are more conservative, at this stage of the development of the LTE-CW relation, it is considered appropriate to opt for a test under static load application.…”

“…Although the aggregates were characterised in TU Delft, they were obtained from samplings of the material used in the test sections of short slabs in Chile used by Pradena & Houben (2018) to develop their investigation of the relation LTE-CW for short concrete slabs pavements.…”

“…Salsilli, Wahr, Delgadillo, Huerta, & Sepúlveda (2015) recognise the necessity to make specific studies of LTE in the nondowelled short slabs. In 2018, Pradena & Houben (2018) studied in the field the LTE-CW relation in short slabs made with Chilean aggregates. In this study, although the LTE values tend to decrease as the CW increases, since 0.7 mm the LTE maintains an asymptotic behaviour around the 80% (until 2 mm), instead of continuing the LTE reduction.…”