Research On Performance Of Foaming Agent For Foamed Concrete

Foam concrete is a lightweight,thermal insulation,sound insulation material and has excellent characters on fire resistance and freezing resistance.Foam concrete is also widely used in building efficiency and other fields.Many factors have ability to influence the performance of foam concrete,especially foaming agent.In this paper,three main foaming agents(composite foaming agent,compound foaming agent and protein foaming agent)were researched on the aspects: foaming performance,modification of foam stability of foaming agents,preparation of cement products including foaming agents.The main research contents are as follows.Firstly,it was studied that the foaming performance of sodium dodecyl sulfate(SDS),animal protein,SDS mix dodecyl benzene sulfonate(SDBS)and SDS mix animal protein.And then a mechanism analysis based on surface tension theory was carried out,the results show that the peak values of foam expansion for SDS,animal protein foaming agent,SDBS and SDS mix animal protein foaming agent were respectively 55,28,86 and 106.Comparing the results we can see SDS mix animal protein foaming agent has the highest foam expansion.Secondly,choice the foaming agent which mixes SDS with animal protein as the research object,and then modifying the foaming agent with polyacrylamide(PAM),gelatin and polyvinyl alcohol(PVA),studied the foam stabilities by testing the sedimentation distance,bleeding degree and viscosity of liquid phase of solution.Results show that the sedimentation distance is 20 mm and the bleeding degree is 40 ml for SDS mix animal protein foaming agent when foam expansion reached the highest.After adding 0.02% PAM,0.09% gelatin and 0.02‰PVA,the sedimentation distance for the foaming agent is respectively 13 mm,11mm and 6mm,the bleeding degree is respectively 40 ml,30ml and 40 ml.By contrast,it is ideal option to choice PVA modifying the compound foaming agent and the best dosage for PVA is 0.02‰.Finally,produced foamed concrete with the PVA compound foaming agent.Through analyzing the subsidence degree,density and compressive strength of test specimens which have different strength degree by means of using different water-cement ratio.Results show that all different density specimens have no collapse during testing,which means there is a good consistency between bubbles and cement.At the same time,the performance of specimens also meets the requirements of JG/T 266-2011.And different preparation technics of foam concrete were researched and compared in this paper.