The connection strength of masonry block faced retaining walls

Segmental masonry blocks are widely used as a facing to reinforced soil retaining walls and bridge abutments. Due to the safety critical nature of structures constructed using such systems, concerns are often expressed regarding the connection strength between the soil reinforcing grid and the block facing. With segmental block facings, the blocks are laid without mortar, the reinforcement trapped between the blocks. In the event of a fire in front of a block faced reinforced soil structure, there is therefore potential for loss of structural integrity of the connection, leading to collapse of the facing system. The paper describes the development of a block system which enables the full grid strength to be mobilised between the grid and the blocks, whilst offering protection to the geogrid reinforcement in the event of fire. The resulting wall system was subjected to a half hour fire test and the grid connection strength re-evaluated.