Dorozhko E. The improvement of the method of calculation of thin asphalt concrete layers on a rigid base

The analysis of the constructive solutions and calculation methods for asphalt concrete layers on a rigid base (concrete slabs) is done. Design scheme of the stress-strain state of asphalt concrete layer and cement concrete slab from the effects of thermal deformation and the mathematical model of the stress-strain state of the combined system is proved. The solution of the problem of calculating the stress state of thin asphalt concrete layer on the plate from the joint action of temperature and deformation of the traffic load, which takes into account the duration of the traffic load and temperature deformation is received. The stress-strain state of asphalt concrete layer on a rigid foundation is firstly determined separately from the action of traffic loads and thermal deformation, while taking into account the time of the action loads. Then certain voltage from two separate components summed according to the superposition principle. Temperature coefficient of linear expansion of the asphalt concrete by heating and cooling in the range of positive temperatures experimentally derived. Reference base of the thermal coefficient of linear expansion of the asphalt concrete in the range of above-zero temperatures from 20 °C to 40 °C during heating and cooling was developed. Criteria of durability of thin asphalt concrete layers on a rigid base which took into account the strength of adhesion on the contact layer and the shear resistance of thin asphalt concrete layer on a rigid base are proved. On the basis of the conducted research the recommendations for calculation of thin asphalt concrete layers on a rigid base are given. The minimum allowable thickness of asphalt concrete layer on a rigid base for various regions of Ukraine, which must be considered when designing, to ensure a firm grip on the contact layers for different types of prime coating and the shear resistance of asphalt concrete set. The expected economic effect for the overhaul of the introduction of the improved method of calculation is 324 thousand UAH/km.