Optimization Of Preparation And Construction Of Foam Lightweight Filler

Foam Lightweight Filler,which is FLF for short,has been studied in terms of cementitious materials,foaming agents,mixing ratios,etc.However,the insufficient attention is paid to the change of light soil foam loss and wet bulk density during construction.Considering the problems encountered from FLF engineering process,the experimental and theoretical analysis of several processes for the preparation and construction of foamed lightweight filler will be carried out through laboratory tests and field tests in the paper,which include several parts:(1)The practice were carried out in the coastal high-speed foam lightweight filler project in Taizhou Bay,Some shortcomings were found in the practice process such as high cost of light soil,unstable wet bulk density of the discharge port and great influence of the pouring process on the wet bulk density.There are the later research direction.(2)Five different active agents were added to the composite foaming agent for modification to test the performance of the foaming agent according to find in engineering practice.It is found that sodium dodecylbenzenesulfonate can effectively reduce the surface tension of the foaming agent.Tensile,foaming ratio and foam stability are most favorable when the dosage is between 0.3%-0.7%.Adding the addition of a little gum arabic and polyacrylamide can significantly improve the foam stability such as the gum arabic content is 0.7%-1.0%and the amount of polyacrylamide is 0.3%.The expansion ratio is first increased and then decreased after the incorporation of polyvinyl alcohol and gelatin.The small amount of surfactant can change the sedimentation distance,but there is no qualitative change in the amount of bleeding and too much gelatin can increase the amount of foam bleeding.(3)It is put forward to solve the problem of low cost and low wet weight of lightweight soil in engineering practice by using admixture instead part of cement.The wet bulk density and dry bulk density were tested under different mixing technology for six different mixing ratios of foamed light soil adding mineral powder,fly ash and kaolin.The results show that the increase of the stirring rate will accelerate the mixing of the foam and the cement slurry during the same period,which leads to reach the stabilization of the light soil shortly.The effects of ho-rizontal mixing mortar mixer are better than the vertical shaft mortar mixer.The foam mixing is more uniform and the wet bulk density is more stable.On the one hand,owing the foam mixing time of foam short,the foam mixed is not uniform and the light soil after curing is poor.On the other hand,The longer the mixing time is,the weigher the foam lightweight filler more expensive will be.The foam is broken in the slurry.When using a horizontal mixer to stir the unsanded foam lightweight filler,it is recommended to stir the time for 2min,and the recommended mixing time for sanding light soil is 4min;the vertical shaft mixer is'nt added sand.The recommended mixing time for light soil is 8min and the recommended mixing time for sanding light soil is 4min.(4)In the engineering practice,the pouring process has a great influence on the wet bulk density.The effects of pumping flow,pumping distance and pouring height on the wet bulk density of the foamed lightweight soil were analyzed.The results show that the pumping flow and wet bulk loss are lost.The ratio is inversely correlated.The larger the flow rate,the smaller the loss of wet bulk density;the pumping distance is proportional to the wet volume.The long pumping distance leads to the long residence time of the light soil in the tube and the greater the loss of wet bulk density.The higher the pouring height,the greater the change in bulk density;the greater the design bulk density,the less the bottom bulk density increases.