Experimental Study On Mix Proportion Of Fly Ash Microbead Foam Concrete

In recent years,with the development of ecological civilization construction,the utilization scope of fly ash has been expanding.As the solid waste discharged from thermal power geneproportionn,fly ash microspheres(solid microspheres and hollow microspheres of the sinking part)has lost its activity completely due to the water immersion in the production process,and its density is much higher than the floating part of fly ash microspheres,which results in the utilization rate of fly ash microspheres in the construction field is almost zero.On the other hand,there are still no perfect products for the wall panels of assembled buildings.If fly ash microspheres can be used as the main material of prefabricated wall panels,and fly ash microspheres mortar which can meet the requirements of thermal insulation,sound insulation,light weight and mechanical properties can be developed,the resource utilization of fly ash microspheres will be realized in the prefabricated wall panels of buildings.Therefore,this paper takes fly ash microspheres as the research object,and the main research contents are as follows:(1)The basic properties of fly ash microspheres were tested.The results showed that the bulk density of fly ash microspheres,the apparent density was,and the water absorption rate,results of particle gradation,and the chemical composition,which provided the basis for mix design and test.(2)The mix proportion of fly ash microsphere mortar was designed and 120 samples were made in three batches.The effects of cement dosage,EHD early strength water reducer,naphthalene high-efficiency water reducer,polypropylene fiber and fly ash dosage on the performance of mortar were analyzed.The strength of each age of the test block was determined and the reasonable mix proportion of fly ash micro-bead mortar was determined.Fifteen specimens of12 specimens of 300mm×300mm×30mm were fabricated after the mix proportion was determined.The axial compressive strength,splitting tensile strength,softening coefficient,elastic modulus,thermal conductivity and impermeability of fly ash microsphere mortar were determined.(3)The experimental study on lightweight of fly ash microsphere was made by using YS-10 cement foaming agent,hydrogen peroxide solution,eighteen alkyl sulfate as blowing agent or air entraining agent.A total of 192 batches of16 Mix proportion were made.The effects of cement dosage,foaming rate and additives on the density and strength of fly ash microsphere foam concrete were tested and determined,and a reasonable mix proportion was determined.The thermal conductivity of the fly ash microbead foam concrete was measured and microscopic electron microscope scanning was compared with the fly ash microbead mortar.Finally,the static load test was carried out on the wall panels made of 900mm×900mm×50mm in the mix proportion.The ultimate bearingcapacity of the wallboard,the stress change and the mid span ultimate deflection,and the span of the fly ash microsphere foam concrete wall under different conditions was calculated.