Research On The Preparation And Properties Of Insulation Board Made By Silicon Calcium-Expended Perlite

Expended perlite (EP) is a wildly used light-weight inorganic aggregate in thermal insulation materials for its excellent properties, such as heat insulation, sound absorption, sound insulation, fireproofing, and desirable durability. However, EP and its composites commonly present high water absorption ratio and easily broken, which limits its further popularization and application. To solve problems referred above, preparation technology of EP insulation board was studied, and stress development of EP insulation board in exterior insulation systemeffect was simulated by ANSYS. The results will contribute to the popularization and application of EP insulation board, and proved fundmential theory for wall materials innovation and building energy conservation.(1) A industrial waste (the main component is SiO2) and lime were chosen as silicate source and calcium source, repectively. Portland cement and gypsum were used as adjusting materials. The optimal proportions of cementing materials for EP insulation board prepation were obtained as: calcium by silicon ratio is 0.6, water by binder ratio (w/b) for extrusion molding is 0.45. Portland cement has negative effect on the strength of cementing materal, while gypsum shows a desirable effect. When the dosage of gypsum is 5%, the compressive strength of cementing material can be as high as 34.8 MPa, softening coefficient arrives at 0.591.(2) The influence of room temperature curing time, autoclave temperature, and holding time on the properties of the cementing material was investigated by orthogonal experiment. The optimal parameters are: room temperature curing time is 24h, the autoclave temperature is 180℃, and the holding time is 6h.(3) XRD was applied to analysis the reaction products of the cementing material. The results show that: the reaction degree of the samples without gypsum is relative low, and the main phases are SiO2, Ca(OH)2, tobermorite, and CSH(B). In contrast, the reaction degree of the samples with 5% gypsum is relatively higher, and the main phases are SiO2, tobermorite, and CSH(B).(4) Relationship between bulk density and thermal conductivity, crushing strength, volumetric water absorption can be expressed as: y = 0.0136x0.2701, y = 0.013 x 2? 0.7846 x+ 55.568, 2y = 0.0064 x ? 1.4674 x+ 103.59.(5) EP insulation board was successfully prepared using cementing material obtained and P4, P3 EP. The compressive and flexural strengths of EP insulation board with self-made binder are much higher than those of insulation board prepared by Portland cement. To improve the waterproofing peroperty, hydrophobic treatment was also applied to EP insulation board. Volume water absorption of EP insulation board is reduced significantly even when low concentration of organo-silicone hydrophobic agent was used.(6) According to the climate in Guangzhou, the steady-state temperature field and thermal stress development of two typical exterior insulation systems constituted with EP insulation board were simulated by ANSYS. The results show that the temperature of no insulation wall changes uniformly along the cross-section of the wall from outside to inside, while the temperature of the wall with EP insulation board mutates at the insulating layer, indicating superior thermal insulation effect. Similar conclusion can also be drawn from transient temperature field analysis. Thermal stress and strain existes in the lateral wall and the coners of the wall, thus cracking preventment should be applied to walls with insulation layer.