durability of rice husk ash concrete in chloride-sulfate environments

One of the challenges facing the construction industry is the durability of concrete in unfriendly environments. cement substitute materials such as rice husk ash (rha) can play a positive role in this direction. therefore, the impact of rice husk ash on the behavior of concrete in an aggressive environment was examined experimentally by testing specimens partially submerged in solutions containing chloride and sulfate ions. the strength development and permeability of concrete mixes with 12% rice husk ash replaced by weight of cement were examined, in addition to normal concrete and concrete with a 5% superplasticizer (5%sp). the exposure duration and the maximum size of coarse aggregate were two of the test parameters. the outcomes of the experiments show that rha enhances the properties of concrete and outperforms 5%sp and plain concrete. the compressive strength of rha concrete was 40-60% higher than its equivalent plain concrete. after being exposed to the test solution for more than nine months, the 12%rh concrete's permeability was considerably lower than that of the other two types of concrete. a number of existing strength models were used to predict the splitting tensile and flexural strengths of rh concrete based on the compressive strength, yielding mostly conservative results.