Study On Reinforcement Modification Of Thermal Insulation Gypsum And Internal Insulation System

Grade A thermal insulation materials have poor construction performance,high engineering cost,high water absorption rate,quality problems such as hollow drums,cracking,and leakage,and poor durability.However,in special buildings such as public buildings and high-rise buildings,it is necessary to use grade A non-flammable thermal insulation materials,so the development of new grade A non-flammable thermal insulation materials with good thermal insulation properties has become a prominent problem that needs to be solved urgently.In this paper,flue gas desulfurization building gypsum was used as cementitious material,mixed with fine light aggregates such as vitrified expanded perlite,modified with retarder,polymer latex powder and cellulose ether,reinforced with water reducing agent,cement,?-High strength gypsum plaster,fibers and hydrophobic expanded perlite.Thermal insulation gypsum applied in exterior wall internal insulation system with Grade A non-flammable,good thermal insulation,high strength and excellent crack resistance was studied and prepared.And the interface gypsum mortar and anti-cracking gypsum mortar matched with the thermal insulation gypsum exterior wall internal insulation system were also studied and prepared.The use of vitrified expanded perlite reduced the density,the retarder adjusted the setting time,the latex powder increased tensile bond strength,the cellulose ether improved the water retention.The basic proportion of the thermal insulation gypsum was explored.Water reducer reducing the water requirement of normal consistency,cement improving the amount of hydration products,?-High strength gypsum plaster replacing the building gypsum,fiber strengthening toughness and fine light aggregates particle gradation optimization were used to reinforce thermal insulation gypsum,and the strengthening mechanism was clarified.The proportion and performance of thermal insulation gypsum,interface gypsum mortar and anti-cracking gypsum mortar were studied,and the performance of thermal insulation gypsum external wall internal insulation system was tested and analyzed.The FGD building gypsum has a high density and hardened quickly.The use of vitrified expanded perlite to reduce the density,the retarder to adjust the setting time,the latex powder to increase tensile bond strength,the cellulose ether to improve the water retention,the dosage of 45%of vitrified expanded perlite,the dosage of 0.1%of citric acid,the dosage of 1%of latex powder and the dosage of 0.6%of HPMC were added.Therefore,the basic proportion of thermal insulation gypsum was determined.The water reducer is used to reduce the water requirement for normal consistency to enhance the thermal insulation gypsum.It was determined that the polycarboxylic acid water reducer PC had a good strengthening effect on thermal insulation gypsum.When the critical content was 0.2%,the water requirement for normal consistency was 1.8,and the compressive strength increased from 0.31 MPa to 0.61 MPa.Cement is used to increase the hydration product to enhance the thermal insulation gypsum.It was determined that the OPC content was 10%,the compressive strength of the thermal insulation gypsum 28d was better.The 28d compressive strength increased from 0.31MPa to 0.37 MPa.The?-High-strength gypsum is used to replace the desulfurization building gypsum to reinforce thermal insulation gypsum.It was determined that when the amount of?-type high-strength gypsum was 20%,the compressive strength increased from 0.31 MPa to 0.36 MPa.Fiber is used to reinforce toughness to enhance thermal insulation gypsum.It is determined that PVA fiber had a good strengthening effect on thermal insulation gypsum.When the critical content is 0.7%,the matrix flexural strength increases from 0.11MPa to 0.2MPa,the toughness index TI exceeds 0.21,and the deflection,flexural strength and toughness are all improved.By optimizing the lightweight aggregate grading to strengthen the thermal insulation gypsum,it is determined that the particle size distribution of the vitrified expanded perlite was0.315mm~2mm,which is beneficial to the strength of the thermal insulation gypsum.When it is blended with 15%hydrophobic expanded perlite,the compressive strength increased by 83.9%.The addition of 15%hydrophobic expanded perlite significantly optimized the lightweight aggregate gradation,which increased the compressive strength by 83.9%.According to the above research,the proportioning of 400 kg/m~3 thermal insulation gypsum is determined as FGD building gypsum:vitrified expanded perlite:hydrophobic expanded perlite:citric acid:latex powder:HPMC:PC:OPC:?-High strength gypsum plaster:PVA fiber=700g:485g:134g:1g:10g:6g:2g:100g:200g:6g.The proportion and performance of the interface mortar and anti-cracking mortar were studied.The proportion of interface gypsum mortar and anti-cracking gypsum mortar of the thermal insulation gypsum exterior wall internal insulation system was determined.The PKPM software simulation was used to calculate and analyze.It was found that the thermal insulation gypsum external wall internal insulation system was suitable for hot summer and cold winter area.When the thickness of the insulation layer was 30mm,the heat transfer coefficient of the external wall is 1.21W/(m~2·K),which met the energy saving design of 65%standard.