Analytical study on Durability of Continuous Reinforced Concrete Pavement Mixing Various Admixtures

It is reported that in snowy and cold regions, continuous reinforced concrete pavements (CRCP) would suffer severe corrosions of their internal steel less than 10 years in service, due to the spray of anti-freezing agents. In order to boost the durability of CRCP in such regions, it is necessary to diminish cracks' width appropriately by expansion (Ex) and suppress materials' deterioration by mixing fly ash (FA) with blast furnace cement (BB). This study constructed a kind of full-scale CRCP with various admixtures in the campus of College of Engineering, Nihon University(Koriyama, Fukushima Prefecture, Japan). After concrete was placed, the temperature and strain behavior of CRCP slabs were monitored continuously. Then, the crack risk of the pavement slabs was evaluated analytically with an FEM analysis based on the input values. Ordinary cement was used in the first condition(N), while the other two conditions adopted FA and BB separately, with 20 kg/m3 of Ex added in the formula with FA/BB. It is found that the shrinkage of FA and BB that were mixed with Ex is clearly smaller than that of N, indicating that Ex can reduce the tensile stress of CRCP slabs and suppress the crack risk from early expansion. In addition, the full-scale CRCP’s FEM model was constructed to precisely predict the temperature and strain behavior of CRCP slabs. This model can be used to quantitatively evaluate the crack risk in CRCP with various types of admixtures.