Research Of Lightweight Cement-based Boards Of Fly Ash

With the rapid development of our country economy driving the rise of construction, the demand wall materials in construction have greatly incresed and meanwhile the requirements of the materials are rising, especially for the performance of new wall materials. In the paper, in order to reduce building energy consumption,a new type of light wall materials with a large amount of industrial waste fly ash in cement meet for the peoplerequirements.The materials are made by adding some foam prepared by mechanical methods into the slurry mixture, then after mixing on a seriesof processes.The product is a new type lightweight wall materials containing a large number of closed pores.Material preparation process has great influence on the performance of the materials, in the subject, the material requirements of the production processes are introduce-d firstly, and then the influence of the material components on the performance of the fly ash cement lightweight concrete were analysied. The influence of various factors on the fly ash cement lightweight concrete are evaluated by the dry apparent density and strength of two main basic performance index. The strength of the materials first increased then decreased with the increase of the dosage of fly ash; and its strength also showed a increasing tred with the increase of dosage of water reducing agent, however excessive water reducing agent can cause harmful gaps and stratification. With the increase of water-binder ratio, the liquidity of lurry obviously improved but the strength of the material reduced; As foaming agent content increased, the strength of the material strength drcreased sharply, meanwhile the dry apparent density of the prepared block reduced as the increasing bubble content.The composition of fly ash and the activity of fly ash excitation mechanism are also analyzed in the paper, the contrast tests are conducted to study the influence on the properties of lightweight materials by the presence and absence of exciting agent.Through experiments exciting agents hydrated lime are found to obtain a certain effects on fly ash activity whose excitation effects are better than unhydrated lime, when the content of the hydrated lime is about1%, the fly ash aquired the best activity. The most appropriate mix is when cement content of40%and fly ash content of60%, water-cement ratio of0.38, superplasticizer dosage of0.3%, the foaming agent content of0.4g, hydrated lime content of1%. The test block28days compressive strength is4.58Mpa, dry apparent density is828kg/m3.Fly ash cement based lightweight materials can not only improve the building function, improve the construction quality and efficiency, and can meet the requirements of the construction unit and the modernization of housing industry to achieve the goal of saving energy, effectively using of resources, meanwhile it has the advantages of light weight, energy saving, waste utilization, playing an important practical significance in the development of construction industry.