Roller compacted concrete (RCC) : strength and permeability of horizontal joints

Abstract

Roller compacted concrete is a very dry material consolidated by the use of a powerful external vibratory compacting. It can be defined as concrete no-slump consistency in its unhardened state that it transported, placed and compacted using earth and rockfill construction equipment. Properties of hardened RCC are similar to those of conventional placed concrete. This material is mainly used in gravity or arch/gravity dams on which RCC construction methodology, by concrete layers, involves a high number and an extensive area of horizontal joints. These joints are the weakest part of RCC in terms of sliding stability and uplift. This study analyses the influence of different parameters on the properties of the joints, namely the influence of cimentitious material content (150-230 Kg/m3), percentage of fly ash (30-60%), and maturity of concrete. The results obtained show the importance of knowing the performance of the joint versus time elapsed between the compaction of the upper and lower layer.