MP
M.A. Pradena
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1
Aggregate interlock is the dominant load transfer mechanism in non-dowelled Jointed Plain Concrete Pavements, as the innovative short concrete slabs. Although the Load Transfer Efficiency of this pavement innovation is based on that mechanism, the structural design methods do not relate the Load Transfer Efficiency by aggregate interlock with its direct cause, which is the Crack Width under the joints. The objective of the present article is to characterise in the laboratory the Load Transfer Efficiency−Crack Width relation for innovative short slabs Jointed Plain Concrete Pavements. Additionally, as an alternative to large-scale laboratory tests to study the Load Transfer Efficiency, a practical test on a reduced scale is proposed. The results confirmed that short slabs Jointed Plain Concrete Pavements with high-quality aggregates are able to provide adequate Load Transfer Efficiency (above 70%) without dowels bars. Based on the laboratory results, complemented with previous field data, a Load Transfer Efficiency−Crack Width curve is proposed and made available for structural design methods of short slabs Jointed Plain Concrete Pavements. Finally, the laboratory test on a reduced scale is useful to develop specific Load Transfer Efficiency−Crack Width relations using standard equipment available in traditional concrete laboratories.
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Aggregate interlock is the dominant load transfer mechanism in non-dowelled Jointed Plain Concrete Pavements, as the innovative short concrete slabs. Although the Load Transfer Efficiency of this pavement innovation is based on that mechanism, the structural design methods do not relate the Load Transfer Efficiency by aggregate interlock with its direct cause, which is the Crack Width under the joints. The objective of the present article is to characterise in the laboratory the Load Transfer Efficiency−Crack Width relation for innovative short slabs Jointed Plain Concrete Pavements. Additionally, as an alternative to large-scale laboratory tests to study the Load Transfer Efficiency, a practical test on a reduced scale is proposed. The results confirmed that short slabs Jointed Plain Concrete Pavements with high-quality aggregates are able to provide adequate Load Transfer Efficiency (above 70%) without dowels bars. Based on the laboratory results, complemented with previous field data, a Load Transfer Efficiency−Crack Width curve is proposed and made available for structural design methods of short slabs Jointed Plain Concrete Pavements. Finally, the laboratory test on a reduced scale is useful to develop specific Load Transfer Efficiency−Crack Width relations using standard equipment available in traditional concrete laboratories.
For their characteristics, concrete pavements are particularly valuable in critical traffic hubs as intersections or roundabouts, roads with predominant trucks traffic or bus corridors, bus stops, bus stations, industrial floors, yards and airport aprons. In particular, in Jointed Plain Concrete Pavements (JPCPs) cracks are produced under the joints as a result of the restricted deformations in the concrete at early-age. The in-service JPCP performance is affected by the width of those cracks, especially in non-dowelled JPCPs, where the transfer of loads between slabs depends on the aggregate interlock. This is especially relevant nowadays with the incorporation of the innovative (non-dowelled) short slabs JPCPs. The objective of this thesis is to evaluate the effects of the early-age concrete behaviour on the in-service performance of traditional and short slabs JPCPs. For that, not only the structural performance is considered but also the functional one because it is directly related with the pavement clients’ satisfaction. As part of the analyses, field measurements were performed in JPCPs of Belgium and Chile, including traditional and short slabs JPCPs in urban, interurban, industrial and airport applications. The analyses presented in this thesis (i.e. including the effects of the early-age concrete behaviour on the in-service performance of JPCPs) show the structural, functional and economic advantages of short slabs JPCPs compared to traditional JPCPs, resulting from the reduction of the slab length, the new traffic load configurations, the reduction of slab curvature (and the variation of it) and the finer cracks at joints.
...
For their characteristics, concrete pavements are particularly valuable in critical traffic hubs as intersections or roundabouts, roads with predominant trucks traffic or bus corridors, bus stops, bus stations, industrial floors, yards and airport aprons. In particular, in Jointed Plain Concrete Pavements (JPCPs) cracks are produced under the joints as a result of the restricted deformations in the concrete at early-age. The in-service JPCP performance is affected by the width of those cracks, especially in non-dowelled JPCPs, where the transfer of loads between slabs depends on the aggregate interlock. This is especially relevant nowadays with the incorporation of the innovative (non-dowelled) short slabs JPCPs. The objective of this thesis is to evaluate the effects of the early-age concrete behaviour on the in-service performance of traditional and short slabs JPCPs. For that, not only the structural performance is considered but also the functional one because it is directly related with the pavement clients’ satisfaction. As part of the analyses, field measurements were performed in JPCPs of Belgium and Chile, including traditional and short slabs JPCPs in urban, interurban, industrial and airport applications. The analyses presented in this thesis (i.e. including the effects of the early-age concrete behaviour on the in-service performance of JPCPs) show the structural, functional and economic advantages of short slabs JPCPs compared to traditional JPCPs, resulting from the reduction of the slab length, the new traffic load configurations, the reduction of slab curvature (and the variation of it) and the finer cracks at joints.
During 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.
...
During 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.
Functional thresholds for designmaintenance of urban pavements
Functional criteria for sustainable design of urban pavements
Functional criteria have been mostly defined in urban pavements using subjective methods, rather than by means of objective and repeatable procedures. The Whole
Body Vibration, the Heart Rate Variability, and new technologies to determine the
IRI (International Roughness Index), are nowadays available. For that, an analysis of
available technologies is made under a PC-O (Pavements Clients-Oriented) integral
perspective, including simulations with the HDM-4 computer program. The IRI
criteria for speeds allowed on urban roadways, i.e. the so-called IRIcity criteria, are
proposed in the paper.
...
Functional criteria have been mostly defined in urban pavements using subjective methods, rather than by means of objective and repeatable procedures. The Whole
Body Vibration, the Heart Rate Variability, and new technologies to determine the
IRI (International Roughness Index), are nowadays available. For that, an analysis of
available technologies is made under a PC-O (Pavements Clients-Oriented) integral
perspective, including simulations with the HDM-4 computer program. The IRI
criteria for speeds allowed on urban roadways, i.e. the so-called IRIcity criteria, are
proposed in the paper.