Abstract. The main goal of this thesis was to produce foam concrete by using impure kaolinite coming from the mining industry of Finland. The purpose of making foam concrete was to use as light weight concrete in engineering applications such as thermal/ acoustical insulations and building blocks.
The experimental part consists of two different sets of experiments. The first set of experiments involve fresh properties to determine fresh density, viscosity, yield stress and aeration rate and to find the behavior of sample in the fresh state before curing. The second set of experiments was the harden properties including the compressive strength and water absorption. The purpose for testing was to find the effect of H2O2, molarity of NaOH and the effect of surfactants. The purpose of our study was to check the application of impure kaolinite in the production of light weight foam concrete. Furthermore, XRD and FTIR analysis were carried out to determine the crystalline structure and the chemical properties of the Alkali activated kaolinite. Polarized microscope was used to get insight about the pore structure and the effect of different parameters on the pores structure and size.
The main findings from the study is the possibility to use kaolinite without any processing and production of low temperature (400 ˚C) ceramic like concrete foam. The dosage of H2O2 was varied from 0.5 to 2%, it effected the hardened properties such as compressive strength as it goes from 20 MPa to 15 MPa. Furthermore, it effected the fresh properties of the material, especially the aeration rate. The aeration rate was increasing for all samples when the percentage of H2O2 was increased. The molarity of NaOH was an important factor that affected the water absorption. Microscopic studies showed that the pore structure varied between samples made without surfactants and those with surfactants, that explains the hardened properties of the aerated foam with impure kaolinite
