Research On The Composition, Properties And Key Construction Technology Of PMCC Bridge Pavement

The polymer modified cement concrete(PMCC) has the characteristic of good flexural strength and toughness. This new kind of material is used in the pavement of bridge deck pavemen. The composition, properties and construction technology of PMCC has researched in this paper to satisfy the technology of one-time paving construction.The influence of styrene butadiene polymer latex, consistency of fresh concrete and the ratio of polymer cement on the compactness of PMCC has studied. The consistency of PMCC should control at 5 second, combined with the construction of vibrating compaction for 30 s, mixing for 60 s. The construction time of PMCC should complete within 1h. Based on the key construction technology for one-time paving construction, the flexural toughness was adopted as the core indicator to research the effect of consistency, the ratio of polymer cement, cement dosage and fiber. The pavement material of PMCC with good properties was prepared.The enhancement of fiber, polymer and combination of both were compared, To make further improvement on the flexural toughness of PMCC, the combination of polyester fiber and latex is adopt. The results showed that compared to ordinary cement concrete, the compressive strength of the fiber modified PMCC reduce lightly at the age of 28 day, but the flexural strength, flexural toughness, fracture toughness, fracture energy increased about 44.2%, 289.1%, 397%, 462.8% respectively. The frost resistance grade of the fiber modified PMCC is increased from F150 to F250. In the condition of 5% failure probability, 0.7 stress level, the bending fatigue life increased 883.6%, flexural tensile elastic modulus, abrasion resistance and chloride ion diffusion coefficient decreased 43.1%, 54.8%, 64.1% respectively. Even after 180 days, the polymer still has the ability to improve the mechanical properties of concrete.Modification mechanism study showed that when P/C was 13%, the polymer latex can not involved in cement hydration and delayed cement hydration in the early stage, but in the later age, because of stability and water-retaining property of polymer film, cement hydration has better condition to improve. The polymer has also reduced the void of PMCC and enhance the cohesion between each phase of the concrete. On account of the polymer modified cement has stronger bonding ability, the polyester fibers in the PMCC is not so easy to pull out in the condition of flexural lord, making the modification on the PMCC has better effect than the ordinary cement concreteThe key construction technology and composition of interfacial bonding material has also studied in this paper. The problem of agglomerates formed in the progress of mixing was solved and the interfacial bond strength was also improved. The good perfomance of interfacial bonding material can provide better protection for PMCC.