Decision-making system and verification of pavement diseases treatment scheme for highway reconstruction and extension

Based on the case of a highway reconstruction and extension project in Guangdong Province, a decision-making system for the treatment of the old pavement diseases of semi-rigid base asphalt pavement's reconstruction and extension has been established. The load-carrying capacity of the old pavement structure has been obtained by the Benkleman beam deflectometer; the damage condition of the road surface has been determined by investigation of road surface diseases; the restorability of the pavement diseases has been evaluated by investigation of the pavement maintenance history; the interior damage condition of the pavement has been detected by the three-dimensional ground-penetrating radar; furthermore, the decision-making system of the old pavement damage treatment scheme has been constructed and the treatment scheme of old pavement diseases has been put forward by using the four-hierarchy indexes of ‘the load-carrying capacity + the condition of road surface + the maintenance history + the interior damage condition of the pavement’; and the treatment effect of pavement diseases has been verified by bearing capacity test. The results show that the variation level of the deflection representative value of the old pavement has been reduced by about 8.2% ∼ 25.1% by adopting different diseases treatment schemes in different sections; 44.2% by adopting the deep grouting of the roadbed scheme, and 61.6% effectively by using the plan of milling all the asphalt layers and the upper base, and then relaying the C20 plain concrete to the top of the upper base and relaying asphalt mixture. The decision-making system for the treatment of the old pavement diseases of the semi-rigid base asphalt pavement's reconstruction and extension can effectively guide the treatment of old pavement disease, notably improve the load-carrying capacity of old pavement structure and the balance of the load-bearing capacity in different sections of the pavement structure.