Study On Structural Durability Of Permeable Interlocking Block Pavement

In the construction of urban roads,airport roads and other facilities,the basic technical indicators such as the degree of surface smoothness and bearing capacity have received much attention;however,with the continuous expansion of the city scale,the traditional roads in the urban ecology,the durability and easy recovery of the facilities as well as other aspects gradually exposed more and more serious problems.Due to structural impermeability,the traditional compact road surface will cause rain and flood problems in the city,and it will be difficult to repair after the road is damaged,causing many adverse effects on people’s lives.For this reason,in the construction of pavements such as sidewalks and parking lots in cities over the past decade or so,the paving of pavement structures in blocks has become more and more popular.However,the traditional vertical seam-joint block pavement surface itself has insufficient transverse load diffusing capability and serious joint misalignment,which has become an important factor influencing its flatness and other performance properties.It adopts a laterally connected structure and lateral load diffusion effect.The block combination pavement can effectively solve these problems.In view of the repeated coupling of the wheel structure,the block surface of the block will bear repeated bumps at the joints,and the joints may suffer freezing and thawing cycles at low temperatures in winter.These effects may cause fatigue damage to the corners of the block and thus directly affect the service life of the combined track.In addition,rainwater,which contains particle contaminants on the road surface,will also cause the joints to be blocked during the infiltration process at the joints,which will cause the water permeability of the pavement surface to gradually decrease.This paper focuses on the anti-collision ability and freeze-thaw resistance of block joints of transverse diffusion load combined pavement structures in order to reveal the durability of this group of pavement surface structures.Based on the load transfer characteristics of the transverse diffusion load bearing structure,the physical and mechanical behavior analysis of the joint and the damage pattern of the structure has been revealed initially.The finite element method was used to simulate the anti-collision behavior of joints subjected to repeated vertical impacts and the damage behavior under freeze-thaw cycles.Under the laboratory conditions,the fatigue test of the vertical and horizontal load of the assembly structure was carried out,and the indoor quick freeze-thaw test was conducted.The results of the study indicate that small particle plugs(particle size range from0.5 to 1 cm)with larger particle plugging(particle size range of 1 to 1.5 cm)can more easily to block the joints of the water-permeable composite pavement;The damage path during loading was carried out along the corners concrete when blocks are subjected to cyclical wheel pressure,and the cracks of the block was broken at about 8000 load cycles,and the corners of the structure were destroyed.The freeze-thaw damage of concrete blocks tends to be slower at first and then faster,but the overall damage is small,and the block can withstand the low temperature effect of about 7.5 years in Tianjin and about 30 years in central China;the cracks tend to appear at the interface zone around the weak aggregates.and will develop toward the place where the initial defect such as the small hole exists.When turbid water infiltrates through the pavement joints,small particle plugging(particle size range of 0.5~1cm)and larger particle plugging(particle size range of 1~1.5cm)will more easily block the joints of the water-permeable combined pavement surface.