The Research On The Preparation And Performance Of Gypsum-based Foam Insulation Material

The requirement of building energy saving is becoming more and more high with the rapid development of China's economy;It was to reduce energy consumption as far as possible,and improve the energy efficiency of building energy efficiency in building construction and building materials in the process of using the same requirements or the same purpose to building energy saving construction.From the point of view of building energy efficiency,gypsum-based cementing composite is prepared by calcined gypsum as base material,adding slag,ordinary portland cement?P.O 32.5? and various additives;Then it is added to the foam prepared by physical foaming process and the mixing is uniform,to make of light weight, high strength, good thermal insulation performance, good water resistance and other excellent properties of gypsum based foam insulation material.Influences of various factors on gypsum-based foam insulation materials were studied systematically.The main research results of this project are as follows:1)The building gypsum,slag and Portland cement ?P.032.5? optimal formula was determined by a large number of experiments;The study showed that the composite materials with calcined gypsum:slag:ordinary portland cement?P.O 32.5?=7:3:1,2% of alkaline activator content,0.5% of the retarder dosage have 1607kg/m³ in apparent density, ?28days? 5.15MPa in tensile strength,28.66MPa in compressive strength,13 minutes in initial setting time,23 minutes in final setting time,0.98 in soften-coefficient,7.5% in water absorption rate.2)The ettringite?AFt? and calcium sulfate dehydrate is basic structural skeleton of the hydration hardening body,the higher content of xonotlite(Ca₆Si₆O₁₇?OH?₂) and calcium silicate hydrate?C-S-H?,the higher strength,and the better water-resistant performance to the gypsum-based composite.3)The foam stability was improved by adding mass fraction 0.2% of foam stabilizer to the diluted foaming agent solution;In order to make the bubble hole in the heat insulating material became more uniform and compact and improve the bending resistance and the compressive strength,we added 2% of glass fiber and 1.5% of polyvinyl alcohol ?PVA? fiber to the gypsum-based composite cementing material. The results showed that when the prepared samples apparent density was 600kg/m³,the thermal conductivity was 0.122W/?m·K?, the compressive strength reached 3.9MPa, after 15 times freeze thaw cycling experiments,the mass loss rate was 2.4%, the strength loss rate was 14.5%.4)Additives can significantly improve gypsum based foaming thermal insulation materia's physical and mechanical properties.The optimal amount of water reducing agent was 0.2%,hydrophobic agent was 0.05%,lignocellulose was 0.2%,P.O32.5 cement was 11.7%,slag powder was 29.9%.5)The thermal conductivity coefficient and the product thermal performance of gypsum-based insulation material was tested and the curve of the dry apparent density and thermal conductivity of the thermal insulation material was drawn. And the curve of the two curves were fitted, The fitted polymerization equation was ?= 0.0572+7.086×10^-4·?-9.37×10^-7·?²+4.26×10^-10·?³.