Evaluation of interlocking block pavement performance under varying construction conditions by model chamber tests

As the demand for interlocking block pavements (IBPs) grows to accommodate diverse traffic loads, it is crucial to comprehensively understand how construction conditions, such as block thickness, joint width, and bedding thickness, affect IBP performance. This study addresses these factors through a series of repeated loading tests on model IBPs constructed with bedding thicknesses of 30, 50, and 80 mm and joint widths of 5 and 8 mm for 100 mm-thick general blocks, and bedding thicknesses of 50, 80, and 110 mm with a joint width of 5 mm for 160 mm-thick heavy-duty blocks. The performance of IBPs was evaluated based on deflection resistance, load-dispersion ability, and interlocking effect, the latter being assessed through the relative deflection of adjoining blocks, a key mechanism for load resistance in IBPs. The results demonstrated that an enhanced interlocking effect was achievable with a bedding thickness of 50 mm and a joint width of 5 mm for general blocks. Additionally, heavy-duty blocks required an increased bedding thickness of 80 mm to achieve greater interlocking. Under these conditions, the blocks rotated sufficiently to produce an arching effect and higher relative deflection. Conversely, IBPs constructed under inadequate conditions exhibited rutting failures, with a maximum block uplift of 0.374 mm due to excessive stress transmission to the base and bedding sand migration. Finally, the elastic modulus, estimated from transmitted stress, reached higher values of 5417.06 and 2075.45 MPa for general and heavy-duty blocks, respectively, under optimal construction conditions. This study highlights the importance of construction factors in ensuring IBP performance and suggests that both deflection and interlocking effect should be considered key performance indicators.