Performance evaluation of innovative concrete armor unit for coastal protection structure

Abstract

Various local innovative armor units for coastal protection structure have been developed to mitigate and control serious coastal erosion problems. The armor units designed by researchers from several institutions in Malaysia include SAUH, SINE SLAB, L-Block and Labuan Block armor. These armor units were implemented to prevent critical erosion problems along various stretches of Malaysia's coastline. This paper discusses the site assessment that was conducted covering selected coastal protection projects along West Coast of Peninsular Malaysia to evaluate the' performance level and identify concerns regarding these armor units. Initial condition of the armor units and the site location were identified and documented as the base condition for the performance evaluation. Comparisons were later made with current observation and findings. The breakage, displacement and settlement of the armor units were noted and any sign of accretion and erosion were also taken into consideration. Most of the armor units remain intact in their initial position especially SAUH and SINESLAB armor units. Corrosion of reinforcement steel bars was observed in most of the armor units as evidenced from the presence of brownish color substance at the concrete surface. This was caused by intrusion of salt water in the concrete through minor fractures and gaps. No major failure on the armor unit was observed during the site assessment indicating good structural stability as expected in their design life. Overall, the impIemented schemes were observed to be performing successfully with occurrence of accretion at most of the sites. The findings and result from this site assessment are important as guidance for future research and other initiative to improve the current innovations. The up-to-date assessment are also critical to estimate further maintenance works to prevent major failure due to prolong exposure to damage that may lead to potentially high maintenance costs to local authorities and nearby residences.