Analysis of Factors Influencing Self-compacting Concrete Construction Quality for Prefabricated Track Slabs in Urban Rail Transit

Objective In response to the problems of narrow construction space, difficulty in controlling the construction quality of prefabricated track slab subgrade, and high requirements for the construction quality of self-compacting concrete in metro construction, the factors influencing the self-compacting concrete construction quality are analyzed through on-site experiments. Method The influence of different mix proportions, construction fixtures, construction techniques, concrete transportation duration, and construction environment on the quality of self-compacting concrete is analyzed through experiments. Result & Conclusion The appropriate dosage of viscosity modifier for self-compacting concrete optimal mix proportion should be 30 kg/m3, a sand ratio of approximately 50% and a fly ash amount controlled within 15% to 25%. The infusion height of observation holes should be maintained between 20 to 30 cm, employing a ′slow-fast-slow′ infusion technique with an infusion time of at least 3 minutes. The material for pouring funnels should preferably be made of steel plates with a thickness of 2 mm or more, and gate valves should be used for intermediate hoppers.