Engineering properties of hybrid foam concrete based on waste glass powder and red pine cone powder

This study aims to investigate the fresh, mechanical, physical, thermal, freeze-thaw and sulfate resistance performances of foam concrete production with the combined use of glass powder (GP) and Turkish red pine powder (RPP) wastes. In this respect, the study is the first comprehensive evaluation of two different waste types in the same matrix, employing a hybrid approach, and offers a holistic perspective on both sustainability and durability. Additionally, the systematic presentation of the resistance behaviors of foam concrete against various environmental conditions, including freeze-thaw cycles, high temperatures, and sulfate effects, is a notable contribution. In the study, 12 different mixtures were produced using 10 % and 20 % GP, and 5 %, 10 %, and 25 % RPP. Mechanical, physical, high-temperature, and durability tests were then performed. In the results, increasing the RPP ratio to 25 % reduced the flow diameter by 20 %, the oven-dried density by 15 %, and the 28-day compressive strength by 55 %. Increasing the GP usage ratio to 20 % resulted in a 40 % decrease in the 28-day compressive strength and a 10 % increase in the flow diameter. In the freeze-thaw tests, at the end of 100 cycles, the strength loss in mixtures containing high GP and RPP reached 65 %, whereas this rate remained between 10 % and 15 % in mixtures without additives. While the strength decreased to 3.57 MPa in mixtures with high additives at the end of 120 days under the effect of sulfate, the mixture without additives maintained its value of 10.65 MPa. This study demonstrates that it is possible to utilize GP and RPP wastes in foam concrete production; however, the optimum additive ratios need to be determined. Thus, it contributes to both waste recycling and the production of environmentally friendly, lightweight building materials.