Mechanical properties of lightweight foam concrete filler for roadbed of high-speed railway

Abstract A high-speed railway has high requirements for line smoothness, and uneven settlement control is the primary factor considered in design operation of subgrade. The emergence lightweight subgrade structures meets needs development railway. As a kind filling material with good performance, foam concrete can effectively reduce load excessive cost foundation treatment. This paper studied dynamic characteristics different wet densities water-bearing states under train loading. effects density fly ash content on compressibility, impermeability, frost resistance were analyzed detail. results show that still residual strength after compression, which about 60% its peak strength. Under mix ratios, critical stress generally 0.2–0.3 times unconfined compressive strength, elastic modulus increases increase cyclic amplitude. With increasing, volume water absorption decreases first then increases, value 40%. gradually density, sample 279 kg·m −3 lost 41.1% 20 freeze–thaw cycles. When 20%, equivalent to pure cement.