Synthesis Of A Synthetic Based Foaming Agent And Evaluation Of The Effects Of Its Foam On Foamed Concrete

The purpose of this study was to design a foaming agent that contains an organic solvent and synthetic surfactants, then study its properties and its performance in mortar slurry. This foaming agent's foam in combination with a superplasticer and various percentages of Metakaolin and Titanium oxide nanoparticles was then used to create high density foamed concrete(density above 1600kg/m3) whose properties such as water absorption and compressive strength were studied under different curing conditions.A foaming agent was created using synthetic based surfactants. Surfactants are organic amphiphilic compounds that contain both hydrophobic and hydrophilic groups. Their primary purpose is to reduce the surface tension of water, and hence make it easier for foam to be created when high speed compressed air and the foaming solution intermix in high density restriction areas(forming lance). This foaming agent contained Sodium lauryl sulfate, Ethanol, Lauryl alcohol and Water. On dilution in water and aeration, this foaming agent created a stable foam whose properties such as dilution ratio, density, capacity and drainage were studied.This foam was then mechanically entrained in mortar slurry to create foamed concrete whose properties such density stability, compressive strength and water absorption were investigated. Test results on foam showed that the initial foam density was 104 kg/m3 at an optimum dilution ratio of 1:40. Test results of foamed concrete showed that its density varied from 450kg/m3 to 1950kg/m3 and, its compressive strength varied from 0.5-23 MPa. On comparison to Eabassoc foaming agent, this foaming agent's foam achieved a higher compressive strength at 28 days. According to ASTM 869-91, this chemical composition qualified to be used as a foaming agent.After being qualified as an appropriate foaming agent, high density foamed concrete(foamed concrete above 1600kg/m3) containing foam generated from this foaming agent and various percentages of Metakaolin(MK) and Titanium oxide nanoparticles(NTO) was made, and the effect of curing on its compressive strength and water absorption was studied. This foamed concrete was cured in air at room temperature of 25±2oC, water immersion at 25±2oC, oven at 80±2oC and steam at 80±2oC. Metakaolin(MK) was used to replace cement in weight percentages of 5%, 10 or 15% and Titanium oxide nanoparticles(NTO) in weight percentages of 1, 2, 3, 4 or 5%. The effect of curing, of MK, of NTO and of combined NTO and MK on the water absorption and compressive strength of high density foamed concrete was investigated.Comparing two mix designs with the first containing only NTO(C2) and the second without NTO and MK(C1), Test rests revealed that 3day water cured C1 and C2 specimens had the highest compressive strength compared to other curing conditions such as oven curing, steam curing, air curing and water immersion curing. It was observed that specimens containing only NTO(C2) had the lowest water absorption and compressive strength compared to C1. Specimens C1(without NTO and MK) had a higher 28 day compressive strength compared to C2 specimens that contained only 3%NTO.Specimens C3, C4 and C5 contained only MK in proportions of 5%MK, 10%MK and 15%Mk respectively. Comparing test results of C3, C4 and C5 specimens, the optimum percentage of MK that gives the highest compressive strength was 10% MK specifically for specimens cured in water till tested. Three(3) day water cured specimens showed an increase in water absorption when the percentage of MK increased.C6, C7, C8, C9 and C10 specimens contained both MK and NTO. The percentage of MK was 10% for all specimens, but the percentage of NTO varied from 1%, 2%, 3%, 4% and 5% respectively. According to test results, the optimum percentage of NTO and MK that gave the highest 28 day compressive strength was 10%MK and 3%NTO. All specimens cured in water showed the highest compressive strength followed by steam cured specimens and lastly oven cured specimens. It was also noted that the water absorption of specimens increased with increase in compressive strength with oven cured specimens having the lowest water absorption, steam cured specimens with the second highest and water cured specimens with the highest water of absorption.