Title: Factors Affecting Load Transfer Across Transverse Joints in Jointed Concrete Pavements
Author(s): N. Buch
Publication: Symposium Paper
Appears on pages(s): 43-64
Keywords: Aggregate; concrete pavements; crack width and spacing; cyclic loads; finite element method; jointed concrete pavement; load transfer; shear stresses
This paper presents preliminary results of a laboratory and a finite element investigation of the behavior of joints in jointed concrete pavement systems in terms of load transfer derived through aggregate interlock. The results have thus far revealed that aggregate type, texture and shape have a pronounced effect on the load transfer mechanism of an undoweled joint in a concrete pavement system. Pure aggregate interlock is not sufficient to provide adequate load transfer over a long period of time. The load transfer mechanism of an undoweled joint was modeled by a two-phase system (cement matrix and aggregates). This approach produced results that were confirmed by experimental results. The finite element analysis demonstrated that the load transfer mechanism is sensitive to slab thickness, modulus of subgrade support, and joint stiffness (aggregate interlock factor). This analysis also indicates that the shear capacity of a joint is a function of the aggregate interlock factor, subgrade modulus, magnitude of load, and crack width. The finite element modeling indicated that undoweled joints in thinner pavements resting on weak subgrades tend to develop high shear stresses (and load transfer efficiencies) and subsequently a lower Endurance Index.