Research on performance improvement of high slump concrete for continuously reinforced concrete pavement

During the construction of Continuously Reinforced Concrete Pavement [CRCP], the lateral pouring method requires the high slump of concrete. In order to improve the performance of High Slump Concrete [HSC] for CRCP, an orthogonal experiment was designed to optimize the HSC mix proportion, and the matrix analysis method was used to determine the optimal mix proportion. Furthermore, the early age cracking risk of HSC-CRCP structure was analyzed by ABAQUS. Hydroxypropyl Methyl Cellulose [HPMC] and Basalt Fibers [BF] were used to enhance the performance of HSC, and the optimal contents of HPMC and BF were determined. The results showed that the importance ranking of various factors was: water-binder ratio [W/B] > polycarboxylate superplasticizer content [PCE/%] > sand ratio [βs/%] > slag powder content [SP/%] > fly ash content [FA/%]. The HSC-CRCP structure still had cracking risk during the early age of 15~21 days. The optimal content of HPMC and BF was 0.025 % and 0.15 %, respectively. The segregation rate [SR], shrinkage rate of 28 day early age [ε], and total cracking area per unit area [c] of HSC were reduced by 87.4 %, 37.0 %, and 38.9 %, respectively, while the compressive strength [fcu], splitting tensile strength [fts], and flexural strength [ff] were increased by 9.8 %, 11.0 %, and 7.1 %, respectively. The findings have significant value for improving the durability of CRCP.