Research On Design And Construction Technology Of Ultra-thin Asphalt Concrete Overlay On Cement Concrete Pavement

GT TECH ultra-thin asphalt overlay is a kind of hot mix asphalt concrete structure layer with thickness of 0.8cm ～ 2.0cm.After forming,the pavement has good anti-crack,anti-seepage,anti-slide and noise reduction function,and the cost is moderate,and can be applied to bridge,tunnel pavement reconstruction,highway and urban road pavement reconstruction and maintenance.This study relies on the construction of the test section,and compares the common pavement structure of the "white to black" project surrounding the test section.This paper summarizes the investigation and analysis of the current cement concrete pavement before the renovation,and gives suggestions on the treatment plan of the old cement pavement.It also elaborate on the technical requirements and test methods of the raw materials used in the ultra-thin asphalt concrete.In this paper,according to the performance requirements of the ultra-thin asphalt overlay,a suitable mineral gradation was formulated.The standard Marshall specimens were prepared with the proposed mixture gradation,and the rut test was used to evaluate the high-temperature stability of the ultra-thin asphalt mixture;the four-point bending beam fatigue test was used to evaluate the low-temperature performance of the ultra-thin asphalt mixture;the immersion Marshall test and the freeze-thaw split test were used to evaluate the water stability of the ultra-thin asphalt mixture;the Kentaburg dispersion test was used to evaluate the adhesion between the asphalt and the stone inside the ultra-thin asphalt mixture.Furthermore,the road performance of the GT TECH ultra-thin asphalt mixture proposed in this study was evaluated.According to the construction of GT TECH ultra-thin asphalt coverlay on the test section of provincial highway S352 line,this paper systematically summarizes the selection of construction machinery and construction technology of ultra-thin asphalt cover layer.The paper also puts forward specific requirements for the quality acceptance of ultra-thin asphalt overlay.Finally,from the on-site inspection of the paved test road section,including on-site friction coefficient,structural depth,water permeability coefficient,pavement thickness,pull-out bond strength,driving noise and other indicators,it is concluded that the ultra-thin asphalt overlay has good road performance and is worthy of application and promotion in practical engineering.The results of this paper have important reference significance for the design and construction of ultra-thin asphalt overlay on old cement concrete pavement.