Research On Waterproofness Of Expanded Perlite Thermal Insulation Mortar

At present,organic insulation materials are mainly used in insulation material in China.This type of insulation material has the advantage of light,smaller thermal conductivity,and so on.But its fireproof performance and durability are poor and release toxic gases easily under the high temperature.Comparing with organic insulation materials,inorganic insulation mortar is a king of building materials with better comprehensive properties and green environmental protection.Its characteristics are higher compressive strength,good fireproof performance and durability.Expanded pearlite thermal insulation mortar is applied widely and an important variety of inorganic insulation mortar.Durability and thermal insulation performance of this mortar are affected by the defects of ubiquitous bigger water absorption of expanded thermal insulation mortar.Modified expanded perlite,component materials,the classification waterproof material,modification method and so on,are taken to research thermal insulation mortar.The influence law of water absorption of expanded perlite affected by the hydrophobic agent,the properties of thermal insulation mortar affected by components,water absorption of thermal insulation mortar affected by the classification waterproof materials and its water absorption affected by modification method,are deeply analyzed.The results of hydrophobicity modified expanded perlite show that:Three kinds of hydrophobic agent can also decrease water absorption and water absorption rate of expanded perlite and enhance water proofness of expanded perlite.When the concentration of silicone water-proofing agent is 0.3%,modification effect is best.The water absorption of perlite can be decreased from 290 mass%to 92 mass%.The basic ratio results show that:When mass-volume concentration ranges froml:4 to 1:8.With the increasing of the mixing amount of expanded perlite aggregate,the dry density,compressive strength and softening coefficient of insulation mortar decrease,the water absorption increases.When content of fly ash ranges from 0%to 30%.With the increasing of the mixing amount of fly ash,the compressive strength and softening coefficient increase,the dry density and water absorption declined slightly,Its rational content is 20%.Redisperdible powder have less significant influence on the properties of thermal insulation mortar.When the concentration of redisperdible powder was 3%,the properties of mortar are better.When content of air entrining agent range from 0%to 0.3%.With the increasing of the mixing amount of air entrining agent,the dry density and compressive strength decrease,the water absorption and softening coefficient increase and then decrease,Its rational content is 0.3%.With the incorporation of water reducing agent,the dry density,compressive strength and softening coefficient increase and then decrease,the water absorption is contrary.When content of cellulose ether ranges from 0%to 0.3%.With the increasing of the mixing amount of cellulose ether,the dry density decrease and then increase,the water absorption is contrary,the compressive strength and softening coefficient gradual increase.When water binder ratio range from 0.9 to 1.2.With the increasing of the mixing amount of water,the dry density decrease,the compressive strength and softening coefficient increase and then decrease,the water absorption gradual increase.In order to optimize mix proportion,orthogonal experiment is conducted at the basis of single factor experiment.Its mass-volume ration(the ratio between quality of cementing material and aggregate volume),fly ash,redispersible powder,air entrining agent,water reducing agent,cellulose ether and water-binder ratio are 1:5,20%,3%,0.3%,1.5%,0.6%,1.0,respectively.The results of adding waterproof materials show that:When single factor experiment is taken to add waterproof materials,waterproof effect are expanding agent>organosilicon waterproofing agent>capillary crystalline waterproof master batch.With the increasing of the mixing amount of them,the water absorption are also decrease.When orthogonal experiment is taken to double add waterproof materials,effecting the important order of 2h water absorption and 24h water absorption are expanding agent,capillary crystalline waterproof master batch,organosilicon waterproofing agent.Compared with single adding,waterproof effect of thermal insulation mortar of double adding waterproof materials is better.The mixing amount of each material is expanding agent 12%,infiltration crystalline waterproof master batch 9%,organosilicon waterproofing agent 7%.Comparing with internal doping with soaking,insulation mortar water absorption of internal doping organosilicon waterproofing agent is less then soaking organosilicon waterproofing agent.Namely,waterproof effect of internal doping organosilicon waterproofing agent is best.In conclusion,The thermal insulation mortar of mass-volume concentration,fly ash,redispersible powder,air entrining agent,water reducing agent,cellulose ether,water-binder ratio,expanding agent,capillary crystalline waterproof masterbatch,waterproofing agent are 1:5,20%,3%,0.3%,1.5%,0.6%,1.0,14%,7%,7%,respectively.According to the optimum proportion,thermal insulation mortar are prepared sample and properties are tested.Its dry density,compressive strength,thermal conductivity,2h water absorption and 24h water absorption are 341 kg/m3,1.12 MPa,0.0751 W/m·K,11.05%,16.70%,respectively,meeting the national standard GB/T 20473-2006?Dry-mixed themal insulating composition for buildings?requirements.