Optimization of lightweight foamed concrete using fly ash based on mechanical properties

Since weight loss in structures has reduced the effect of earthquake; many researchers have focused on the use of foamed concrete. Using foamed concrete with fly ash could be used as a great solution to reduce carbon footprint of concrete. The main objective of this research is to study the mechanical properties of concrete by using foam and fly ash, meanwhile the effective parameters on its strength, density and durability. Therefore, the survey investigates the characteristics of foamed concrete by means of laboratory sampling and trying to increase concrete's strength, while reducing the weight of concrete. First, to obtain the optimal foam percentage, various percentages of foam were replaced with concrete mortar and tested under a compressive strength test. Then the samples were tested with various percentages of fly ash to evaluate their strength. The results demonstrate that the concrete with a mix design of 10% foam and 15% fly ash has reached the maximum value of compressive strength on 28 days of curing, equivalent to 24.7 MPa. Furthermore, the highest value of splitting tensile strength of concrete with 10% foam, 15% and 5% fly ash is about 3.3 MPa. At the end of this study, the optimum percentage of fly ash was replaced with super fly ash to compare their results.