Abstract from original publication: Foam concrete refers to a type of low-density concrete that is commonly known to have favorable insulation and thermal performance due to its intentionally increased porosity. However, foam concrete is known to generally have a very low physico-mechanical and durability performance mainly due to its high porosity and the con- nectivity of the pores that can allow the entrance of unfavorable substances into the concrete medium. As a result, most often, foam concrete is considered inapplicable to major load bearing structural elements. To counter this tendency, this study adopted the use of basalt fibers with silica fume to increase the structural integrity of foam concrete. In that respect, 18 mixes with varying content of foaming agent, basalt fiber and silica fume have been prepared. Apparent porosity, water absorption, compressive, flexural and splitting tensile strength, sorp- tivity, ultrasonic pulse velocity (UPV), drying shrinkage, freeze–thaw, thermal conductivity, and thermal resis- tance tests were performed to evaluate the physico-mechanical, durability, and insulation properties of the produced foam concretes. Based on the results, a highly durable foam concrete with a maximum compressive, flexural and splitting tensile strength of ~ 46, 6.9 and 3.07 MPa, respectively, has been developed. Furthermore, it is observed that the inclusion of silica fume can significantly influence the pore network and enhance fiber- paste matrix. The effect of basalt fiber, however, is found to be more dependent on the use of silica fume, potentially due to its low integration with cementitious paste. The results of this study are significant and point out to the great potential for producing a highly durable and lightweight insulating foam concrete through the use of basalt fiber and silica fume. [1]
For thermal conductivity test, a C-therm, TCi Thermal Conductivity Analyzer with a thermal conductivity range of 0 to 500 W/mK, conforming to ASTM D7984 was used. In this test, a constant momentary heat pulse is applied on the surface of the test sample, thermal effusivity is determined as the temperature increases at the surface of the material with elapsed time. [1]
a) Thermal conductivity and b) thermal conductivity versus dry unit weight of different foam concretes. [1]
[1] Osman Gencel, Mehrab Nodehi, Oguzhan Yavuz Bayraktar, Gokhan Kaplan, Ahmet Benli, Aliakbar Gholampour, Togay Ozbakkaloglu, Basalt fiber-reinforced foam concrete containing silica fume: An experimental study, Construction and Building Materials, Volume 326, 2022, 126861, ISSN 0950-0618, https://doi.org/10.1016/j.conbuildmat.2022.126861. (https://www.sciencedirect.com/science/article/pii/S0950061822005475)