Volume Compatibility of Interlayer Treatment Materials with Roller-Compacted Concrete

Interlayer is the weakest plane of the entire roller-compacted concrete (RCC) structure and is easily deteriorated under the pressure of water and other environmental factors. Shearing force induced by the different shrinkage in interlayer part is the main reason for that poor performance of the RCC. In this paper, the deformation of RCC concrete and interlayer treatment mortar with supplementary cementitious materials (SCMs, including fly ash and silica fume) and double expansive resources admixtures (HME, containing calcium sulphoaluminate (CSA) and CaO) were studied. Deformation of concrete (produced RCC) and interlayer treatment materials was modeled and compared. Porosity characters of interlayer treatment materials and water absorption of interlayer-treated RCC samples were tested. Results showed that the HME significantly reduced the shrinkage of mortar and the deformation difference degree between layers was shortened. Modified interlayer treatment materials with HME could modify the macroscopic properties of RCC, the low porosity of interlayer and water absorption of interlayer-treated RCC was resulted. The suitable HME content is necessary in interlayer treatment materials and which could improve the performance of RCC.