Research On Preparation And Properties Of Aerated Shale Block

As global energy situation becoming more desperate, various countries around the word confirmed growing concern over energy issues. In the forms of energy consumption, the proportion of building energy consumption is rising year by year. It's an important issue in the construction field to reduce energy consumption effectively and popularize energy-saving building.At present, aerated concrete, hollow bricks, perforated brick and concrete hollow blocks are widely used as energy-saving wall materials. With the popularization of the third step of building energy-saving, single wall materials such as hollow bricks, perforated brick and concrete hollow blocks can't achieve the requirements for the thermal performance of building envelope. While aerated concrete exists some defects such as large shrinkage and easy-cracking. The purpose of this thesis is to research one type of aerated shale block with low thermal conductivity and volume stability.The preparation method and performance of aerated shale block was explored in this thesis, the effect of w/s ratios, dosage of Methyl Cellulose, types of foaming agent, particle size distribution of shale and sintering system on mechanical properties, thermal property and durabilities of aerated shale block were studied. The results showed that:①Drying shrinkage and compressive strength of specimens were effected by foaming ways and the types of foaming agents, the properties of specimens foamed by protide foaming agent were better than that of rosin-based foaming agent.②Compressive strength was affected obviously by slump flow of shale paste. The slump flow of shale paste should be controlled between 95mm~115mm.③Compressive strength of specimens was raised from 2.8MPa to 5.5MPa, while MC dosage was raised from 1.5% to 2.0%. Strength of specimens were affected mainly by bulk density but not MC dosage while MC dosage changing between 2.0%~3.0%.④There was remarkable effect of reducing water absorption and enhancing compressive strength by increasing content of particles whose size less than 80μm.⑤When specimens were dried at the drying system of increasing temperature gradiently, which was drying at 40℃for 12h, 50℃for 4h, keeping 55℃until drying out, their performance was better than that were dried at 40℃.⑥With sintering temperature increased, sintered shrinkage and compressive strength enhanced obviously while water absorption reduced. Specimens deformed seriously while sintering temperature reached 1150℃.Compressive strength of specimens increased with the holding time which changed between 2 hours and 6 hours.⑦Aerated shale block with bulk density of 728kg/m~3, compressive strength of 5.1MPa, water absorption of 53.7% and thermal conductivity of about 0.125W/m·K was prepared under the condition of this research.