The traditional cement expanded perlite thermal insulation mortar has a large water absorption rate and poor crack resistance, and can only be used as internal insulation. Its application has great limitations; therefore, research and development and promotion of using thermal insulation mortar with better technical economy to promote thermal insulation The upgrading of mortar has important practical significance.
Process waste polystyrene foam (EPS) to a particle size of 0.5!
As a light aggregate, the 5mm granules can effectively overcome the defects of high water absorption and poor crack resistance of perlite thermal insulation mortar, and better thermal insulation. This paper mainly studies the effects of different aggregate particle size distribution and different aggregate content on the working performance and mechanical properties of thermal insulation materials, in order to obtain better thermal insulation materials.
2 Raw materials and test methods 2.1 Raw materials 1) Regenerated EPS particles and expanded perlite 5 R-type silicon cement common water reducer: wood calcium, water reduction rate 7% thickener: methyl cellulose ether accelerator from the base Sex activator finely dispersed polymer, vinyl acetate copolymer, solid powder (water repellent, main component, organosilane, solid powder Table 1 density of aggregate particles and gradation aggregate particle size distribution. Abandoned EPS particles, native EPS particles, expanded perlite, 2.2 samples, damped 70mm triple mold, firstly premix the cement, mineral additives, finely dispersed polymer, thickener, accelerator and water repellent. Then add water for 3%5min to form a viscous slurry, and then add the recycled EPS particles for 3min to become a lightweight, viscous recycled EPS ultra-light concrete slurry. After the test piece is formed, it is placed in a standard curing room for maintenance. After 48 hours, the mold is removed and cured under standard conditions until 28 days. 2.3 Test method Water absorption test The mass of the m1-immersion sample is calculated by the formula aZmrmcVm.)100, g; m. The mass of the sample was dried, g; the arithmetic mean of the results of the three tests was used as the measured value.
Softening coefficient test 70mm, test 28d strength 3 experimental results and discussion 31 The effect of different aggregates on the performance of the experiment using cement, fly ash, mineral powder as a cementitious material, 500g of cementitious material, of which cement is 30 (, pulverized coal Ash 35), mineral powder is 30, the amount of accelerator is 4.3- of the total amount of cementitious material, the amount of water reducing agent is 05. of the total amount of cementitious material, and the amount of air-entraining agent is 0.12 of total amount of cementitious material. The amount of thickener is 0.23 of the total amount of cementitious material, the water-binder ratio is 4470.41, the amount of water is 205ml, and the total amount of aggregate is 1300ml. The percentage of discarded EPS particles, native EPS particles and expanded perlite is shown in Table 2 Table 2 Different proportions of aggregates Mixing ratio No. of discarded EPS native EPS (expanded perlite table 3 different aggregates impact on the performance of thermal insulation materials No. Consistent wet capacity kg/m3) Dry capacity kg/m3) Compressive strength MPa ) flexural strength MPa) water absorption) softening coefficient a primary EPS content against compressive strength b expansion perlite content against compressive strength effect of aggregate compressive strength a influence of native EPS content against folding strength b expansion Effect of perlite content on folding strength Effect of Aggregate Resistance Strength Table 3 lists the effects of different aggregates on the properties of the insulation material mixture and the mechanical properties of the hardened slurry. The effects of different aggregates on the compressive and flexural strength of the insulation materials are shown. It can be seen that the increase of the content of the original EPS particles and the increase of the expanded perlite content can increase the compressive strength and the flexural strength of the test piece. When the waste EPS particles are completely used as the aggregate, the compressive strength of the test piece is 1.16MPa, the flexural strength is 1.24<>. When the original EPS particles are incorporated, the strength of the test piece increases. When the original EPS particle content is 10% of the total aggregate, the compressive strength and flexural strength of the test piece are 1.49MPa and 1.30MPa, respectively increased by 28.4 and 4.CD, when all the original EPS particles were used as aggregate, the compressive strength and flexural strength of the test piece increased to 1.56MPa and 1.35MPa, respectively. Compared with the strength of the specimens using the discarded EPS pellets as aggregates, the strengths of the specimens were increased by 34.5E and 9F, respectively, which indicates that the increase in the amount of the primary EPS particles can significantly improve the strength properties of the specimens. Into the expanded perlite can also improve the strength properties of the test piece. When the amount of expanded perlite is 5G of the total amount of aggregate, the compressive strength and flexural strength of the test piece are 1.31MPa, respectively. And 1.60 MPa, with all discarded EPS particles as Compared with the material, the strength increased by 13H and 191 respectively. When the amount of expanded perlite increased to 10 of the total amount of aggregate, the compressive strength of the test piece further increased to 1.73MPa, and the increase reached 49K. It can be seen that the improvement of the strength properties of the test pieces by the native EPS particles and the expanded perlite is due to the improvement of the pore structure of the test piece. Compared with the discarded EPS particles, the primary EPS particles have a smaller particle size and a uniform distribution. The increase of its content makes the porosity of the test piece lower, the compactness is improved, and the strength of the test piece is increased. The mechanism of the improvement of the strength of the test piece by the expanded perlite is similar. The incorporation of expanded perlite also improves the pore structure of the test piece, increases the compactness of the test piece, increases the strength, increases the influence of a native EPS content on the water absorption rate, and the effect of the expanded perlite content on the water absorption rate. The effect of the material on the water absorption rate The publication in June 2006 showed the effect of different aggregates on the water absorption of the insulation material. It can be seen that the incorporation of the original EPS particles reduces the water absorption rate of the test piece, and all the waste EPS particles are used. As aggregate The water absorption of the test piece is 22.7S. When the original EPS particles of 10T are blended, the water absorption of the test piece is reduced to 16.4U. When the amount of the original EPS particles is increased to 10V of the total aggregate amount, The water absorption of the test piece was further reduced to 153 W. This was also due to the improvement of the pore structure of the test piece by the native EPS particles. As the particle size was smaller, the amount of the original EPS particles with uniform particle distribution increased, and the test piece was The porosity is gradually reduced and the compactness is also increased, so the water absorption of the test piece is declining. The effect of the expanded perlite on the water absorption of the test piece is similar. The improvement of the pore structure of the test piece causes the water absorption rate to decrease. Liu 05% UY'/r Expanding Lingzhu 1 a Effect of native EPS content on softening coefficient b Effect of expanded perlite content on softening coefficient The effect of aggregate on softening coefficient 4 shows the effect of different aggregates on the softening coefficient of thermal insulation material It can be seen that the increase of the content of the original EPS particles reduces the softening coefficient of the test piece. When all the discarded EPS particles are used, the softening coefficient of the test piece is 0.82, and the incorporated native EPS particles are the total aggregate. 10 of the amount! At the time, the softening coefficient of the test piece was reduced to 0.77. When all the native EPS particles were used as the aggregate, the softening coefficient of the test piece was reduced to 0.64. When the expanded perlite content was 5", the waste EPS particles were used as the aggregate. Compared with the aggregate, the softening coefficient of the test piece is reduced. When the amount of expanded perlite continues to increase to 10 of the total aggregate amount, the softening coefficient of the test piece increases, and no expanded perlite is used. Incorporating 5 expanded perlite and 10% expanded perlite, the softening coefficients of the test pieces were 0.82, 0.76, 0.92. The effect of a native EPS content on the dry bulk density. The effect of the expanded perlite content on the dry bulk density. The effect of the material on the dry bulk density shows the effect of the aggregate on the bulk density of the insulation material. It can be seen that the primary EPS particle content is 10 hours of the aggregate amount, and the dry weight of the test piece is compared with the total use of the discarded EPS particles as the aggregate. The increase of kg/n3 is increased to 589.5kg/n3, which should be caused by the improvement of the compactness of the test piece due to the addition of the original EPS particles, but when all the original EPS particles are used as the aggregate, the test piece is dried. The bulk density has been drastically reduced to 517.9 Kg/n3, this may be due to the single gradation of the original aggregate, the large gap between the aggregates, resulting in a decrease in the bulk density. It can be reflected that the increase in the amount of expanded perlite increases the dry bulk density of the test piece. Firstly, the expanded perlite has a significant improvement on the pore structure of the test piece, which makes the compactness of the test piece increase, and the density of the expanded perlite itself is relatively large. As its content increases, the dry bulk density of the test piece increases. Will increase significantly, as the amount of expanded perlite increases from 0 to 5 (, 10), the dry bulk density of the test piece also from 3.2 different bulk density on the performance of the experiment using cement, fly ash, mineral powder as glue The condensed material and the cementing material are taken as 500g, wherein the cement is 304, the fly ash 355, the mineral powder is 358, the amount of the accelerator is 4.39 of the total amount of the cementing material, and the amount of the water reducing agent is 0.5: the total amount of the cementing material. The amount of air entraining agent is 0.1 of the total amount of cementing material, the amount of thickening agent is 0.2 of the total amount of cementing material, and the wind power is not more than 5 grades; when rainy days are constructed, effective measures should be taken to prevent rainwater from scouring the wall surface, base layer The wall and screed should be dry and qualified.
2.2 Preparation before construction Clean up the base layer, make adhesion test, cut the EPS composite board, and modulate the mortar (use it with the equipment, use it within 1h).
2.3 The adhesive of the composite board should be applied to the EPS board and should not be applied to the base layer. The area of ​​the glued material meets the requirements of the specification. The mixture mortar is continuously applied to the heat preservation board in a horizontal direction with a tooth boring tool. The adhesive mixture strip is 1 mm, the thickness is 10 mm, the pitch is 50 mm, and the heat insulation board coated with the binder mixture is immediately pasted on the adhesive layer. On the wall, move quickly to prevent the surface of the binder mixture from losing its bond.
2.4 Anchoring is fixed with mechanical anchors to fix the composite plate. The anchor is installed at least 24 hours after the adhesive is used. The hammer is used to punch the surface of the composite plate inward. The diameter depends on the diameter of the anchor. The depth of the wall is not drilled. Less than the design requirements, screw in or knock in the anchoring nails, the nail head and the disc should not exceed the polystyrene board surface as much as possible, and the number and type of anchor fixing parts are determined according to the design requirements.
2.5 Elastic filling putty construction EPS composite board anchors can be fixed after the anchoring, the gap between the board and the slab can be carried out. The gap between the board and the keel and the surface of the anchor are affixed with a mesh cloth and smoothed with elastic putty, closed on the outer surface. Gap to improve the overall insulation of the insulation.
3 Conclusion According to the actual situation of the project, the EPS composite insulation board system was adopted, which not only ensured the construction quality, but also formed the insulation construction of the entire facade in a relatively short period of time, ensuring the construction of the subsequent exterior wall. At present, there is no applicable technical specification for the application of composite thermal insulation board to external wall insulation, and only relevant specifications can be referred to. In order to further promote the use of composite insulation boards, it is recommended that they should be included in the corresponding technical specifications to facilitate construction and supervision and acceptance.
The effect of the number on the 464th page can be seen that as the wet bulk density of the thermal insulation material increases, the compressive strength of the test piece increases, and the amount of aggregate decreases, so that the compactness of the mixture increases. The strength of the specimen after molding is naturally high; as the wet bulk density of the insulation material increases, the water absorption rate of the specimen decreases, which is also due to the decrease in the amount of EPS particles, which increases the compactness of the mortar and reduces the post-forming test. The porosity of the piece is caused; it can be seen that the increase of the wet bulk density of the slurry has little effect on the softening coefficient, and the softening coefficient can still be maintained at 0.70!
Between 0.80. The relationship between the wet bulk density of the insulation material and the dry bulk density is shown. It can be seen that there is a good correlation between the wet bulk density of the insulation material and the dry bulk density.
The larger the wet bulk density, the larger the dry bulk density, and the dry bulk density can be estimated based on the wet bulk density of the insulation material.
From Tables 6 and 0, the change of dry shrinkage of different bulk density insulation materials is shown. It can be seen that the shrinkage rate of the test pieces under different bulk density gradually increases with time, the shrinkage of the previous test pieces changes greatly, and the test pieces shrink in the later stage. The change in the shrinkage ratio of the different bulk density of the sample 6 is the drying shrinkage rate is gentle. Compared with the lighter weight insulation materials, R-5 and R-6, which have larger bulk density, have larger dry shrinkage and smaller dry shrinkage values ​​due to less aggregate content and relative cementitious material content. More, the shrinkage of the slab of the hardened slurry causes a large contraction of the gang, and in the later stage, due to their relatively small porosity and relatively large elastic modulus, the constraints on the shrinkage of the slurry are relatively large, resulting in their The drying shrinkage rate is low.
4 Conclusions EPS aggregate-level insulation materials have a great impact on the work performance and mechanical properties. The use of native EPS particles has a very good effect on the performance of the insulation material. When the amount of primary EPS particles accounts for 10% of the total amount of aggregate, the strength of the insulation material is improved and the water absorption rate is obviously improved. The use of expanded perlite can also significantly improve the strength properties of the test piece. The water absorption rate of the piece.
The greater the bulk density, the higher the strength of the insulation material and the lower the water absorption rate but the softening coefficient does not change much.
(3) When the amount of EPS aggregate is large, the shrinkage of the insulation material is small in the early stage, and the dry shrinkage is large in the later stage.
(Finish)
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