WEATHERING OF ROCK AS ARMOURSTONE: A CASE STUDY ON BAHRAIN LIMESTONE

Andrea Caricato, Leo Woods, Chandra Mohan

Abstract


Locally-sourced armourstone is used extensively in the construction of new sea defence structures throughout Bahrain, with hundreds of thousands of tonnes being placed on single reclamation projects. This armourstone is won almost exclusively from the local quarry, which outputs limestone of variable quality. An evaluation has been made into the quality of local rock for usage as armourstone, using observations on sites and at the quarry, as well as compliance test results from various projects undertaken in recent years. Attempts are made to quantify potential losses in-service, by using the two degradation models described in the CIRIA Rock Manual, which give markedly different estimates. The envisaged loss of mass is difficult to predict with great accuracy due to the high sensitivity of the models to material and site parameters. Plots of estimated mass loss over time are presented for different rock sizes and different levels of rock armour mobility.

Keywords


armourstone; degradation; weathering; micro-deval; armourstone quality designation; Bahrain

References


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