Study On Coarse Aggregate Interlocking Pavement Concrete: Preparation And Properties

Coarse aggregates play skeleton enhancement in the concrete. To increase aggregate volume fraction can improve the volume stability of concrete, reduce heat of hydration, and reduce the permeability, reduce the costs of materials. Taking into the surplus coefficient of concrete paste is too large and the important role of coarse aggregate, we prepared coarse aggregate interlocking pavement concrete by scattering-filling stone process. The coarse aggregate replacing ratio on the mechanical properties and durability of pavement concrete were studied; the concrete forming method, mixing method, the performance of scattered coarse aggregate on concrete strength and other properties were studied. Finally, according to the stacking rate of coarse aggregate, we give a formula to calculate the optimum volume friction of coarse aggregate in concrete. Innovative achievements made are as follows:(1) The optimum replacement ratio of scattering stone is about 10% in pavement concrete. With filling of coarse aggregate can increase compressive strength of concrete significantly in any age. The flexural strength is lower than the ordinary pavement concrete in early age. The flexural strength can close to or greater than the flexural strength of ordinary pavement concrete in later age. The concrete prepared by scattering-filling stone process have higher elastic modulus, both impact toughness and abrasion resistance are improved.(2) Replacement ratio of 10% by volume, vibrated by table vibration, it is the best way to scatter the coarse aggregate to middle of the concrete and the concrete have the best strength in the long term. Followed by the two-step mixing. Vibrated by vibrating rod, it is the best way to scatter the coarse aggregate to top of the concrete and the concrete have the best strength in the long term. Followed by the two-step mixing. The concrete prepared by scattering-filling stone process have no influence on the strength in the long term. The concrete prepared by scattering-filling stone have the best strength when the coarse aggregate was scattered to the middle of the concrete. Followed by the two-step mixing. (3) The best condition of scattering aggregate is saturated surface and the best size is equal to or slightly larger than the aggregate of reference concrete.(4) With the increase of the scattering-filling stone replacing ratio, the concrete have lower drying shrinkage. Chloride ion permeability coefficient was decreased. So, the concrete have better durability.(5) According to the coarse aggregate stacking rate, through the proposed model and empirical values, we give a concrete mix proportion formula for interlocking pavement concrete and the formula gets a better validation.