Marine Durability Characteristics of Rice Husk Ash-Modified Reinforced Concrete

This paper addresses the potential use of Rice Husk Ash (RHA) as a cementitious material in concrete mixes. RHA is produced from the burning of rice husk which is a byproduct of rice milling. The ash content is about 18-22% by weight of the rice husks. Research has shown that concrete made with RHA as a partial cement substitute to levels of 10% to 20% by weight of cement has superior performance characteristics compared to normal concrete. Also, the use of RHA would result in a reduction of the cost of concrete construction, and the reduction of the environmental greenhouse effects. This paper reviews the research investigations during the past three decades. The significant findings from these include higher compressive strength, and the lower chloride-ion penetrability of RHA modified concrete compared to normal concrete. Further research is being conducted by the authors to determine the resistance to accelerated corrosion in the marine environment, shrinkage and durability, and resistance to chloride ion penetrability of concrete mixes with different percentages of RHA and different water-binder ratios. This project, funded by the National Science Foundation, is a joint effort with a parallel investigation of restricted scope, at Chulalongkorn University, Bangkok, Thailand.