Authors: Pakdee Khobklang and Piyanuch Jaikaew
This paper aims to adopt the Disturbed State Concept (DSC), which is a mechanistic approach, in modelling the behavioral responses of porous concrete to static loading. In this study, gravel was used as the coarse aggregate which was the main variable while the other factors were constant. A three different size of gravel, in accordance with ASTM C 136, was selected, namely gravel retained on sieve #2, #4 and mixing size between #2 and #4. Then the compressive strength and the void ratio of porous concrete were investigated by conducting the tests in laboratory that conform to ASTM C 39 and ASTM C1754, respectively. After that, the experimental results were employed by DSC in establishing an equation for back-predicting compressive strength of porous concrete specimen. The experimental results indicate that compressive strength of porous concrete specimen are affected by their void ratio, i.e. compressive strength of porous concrete is increased when its void ratio is decreased. For DSC modelling, it is found that the disturbance function is around 2.62 times of void ratio and the use of DSC equation in back-predicting compressive strength of porous concrete provides the calculation results that are consistent with the experimental results, in which the percentage of error is less than 5.
Keywords: Disturbed State Concept; porous concrete; compressive strength; void ratio; size of coarse aggregate