Study on Performance and Application of Lightweight Thermal Insulation Mortar for Power Plant Light Sand

The solid waste of power plant was used as lightweight sand to prepare insulation mortar for masonry. The physical and mechanical properties of lightweight thermal insulation mortar were experimentally studied. The influence of lightweight sand on mechanical properties and thermal conductivity of thermal insulation mortar was analyzed. The light-weight masonry thermal insulation mortar and plastering thermal insulation mortar formulated for use in combination with new wall materials can effectively avoid the occurrence of hollow bridges and wall hollowing and cracking.

Power plant bottom slag; Lightweight thermal insulation mortar; Compressive strength; Thermal conductivity In recent years, the comprehensive utilization of fly ash in the economically developed areas on the southeastern coast of China has been in a good situation, dry ash has appeared in places like Jiangsu, Zhejiang and Shanghai. The situation in short supply. However, the comprehensive utilization of bottom slag, which accounts for about 20% of the ash emissions from coal-fired power plants, is still insufficient. At present, more than 90% of the bottom slag at home and abroad is only used as roadbed material or ash landfill, occupying large amounts of land. In China, a small amount of bottom slag is used as coarse aggregate or fine aggregate in building materials, partly to replace river sand or gravel, and in foreign countries it is mainly used as road embankment and grass-roots. The economic benefits of these utilization methods are not high. The volume density of light bottom slag in power plant industrial slag This project uses cement, fly ash, power plant light sand, additives, etc. as raw materials, and according to different proportions, it is prepared by mixing into compressive strength M5.0, M7. 5, M10 masonry insulation mortar and plastering insulation mortar, suitable for industrial and civil building wall masonry and painting.

1 Raw materials and test methods 1.1 Raw materials Cement: The test uses P*O42.5 cement, density 3.03g/cm3, produced by Nantong Huaxin Cement Plant.

Fly ash: Class fly ash, density 2.30g/cm3, produced by Nantong Huaneng Power Plant.

Lightweight sand: the power plant light bottom slag particle size of 1.8mm ~ 5mm) is divided into three categories of coarse, medium and fine, Nantong Huaneng power plant production, its basic properties are shown in Table 1. Admixture: special additives for thermal insulation mortar, Prepared by the project team.

3 Conclusions Contrasting experimental results can be concluded as follows: Screening with a suitable source of iron ore tailings can completely produce graded sand required for exterior wall thermal insulation mortar.

Iron tailings sand is more suitable for the preparation of exterior wall thermal insulation mortar. The prepared mortar can meet the standard requirements and has good performance.

The use of iron tailings and natural quartz sand is not as good as using iron tailings or natural quartz sand alone.

The use of iron ore tailings has the best ratio at the grain level and should be determined for different iron tailings.

The use of iron ore tailings for external thermal insulation bonding and screeding mortars increases the mixing water usage, but does not affect the performance of the mortar. At the same time, the flexibility of the mortar is enhanced.

The adhesive mortar and trowel mortar produced from the best grading iron ore tailings obtained through experiment comparison have been applied in batches in the exterior insulation of polyphenylene sheet and plaster coating of Beijing Wanheng Home. In half a year, experienced severe weather changes in the winter in Beijing, and there were no problems such as emptying or cracking. During the construction process, operators felt that the plaster's hand feel was basically the same as that produced by natural sand.

Table 3 Mortar performance test results Table 1 Basic properties of light sand Lightweight fineness Modulus Apparent density kg/cm3) Bulk density kg/cm3) Membrane excess %) Fine sand Fine sand 1.2 Experimental method 70 The cube compressive strength test specified in -90 Basic Performance Test Method for Building Mortar was carried out. A 70.7mmX70.7mmX70.7mm cube specimen was used to measure the mortar strength of each compounding ratio. Measure the dry density, thermal conductivity, etc. of the specimen with 300mmX00mmX0mm. The determination of the thermal conductivity is based on the standard GB10294-88 Test Method for Thermal Resistance of Thermal Insulation Materials and Related Protective Foil Methods.

1.3 Mortar experiment mix ratio design rule of 98-2000 masonry mortar mix, optimized design of 5 sets of light sand insulation mortar mix ratio and 2 sets of ordinary mortar mix ratio, experimental mix ratio see Table 2. 2 Mortar experiment mix ratio Number of raw materials used kg/m3) Consistency Stratification Water retention rate Wet density Cement sand additive Water Note: K indicates ordinary mortar prepared using ordinary yellow sand, Q indicates that thermal mortar prepared using lightweight sand.

Lightweight mortar preparation requirements: The preparation of light mortar should use compulsory mixer, stirring time is 3min; If using the self-drop type mixer, the mixing time should be 5min. When light mortar is formulated, cement and additives should be added first Stir the water and add light sand to the mixer. The light mortar mix ratio is based on the actual ratio of the design test block. Other construction techniques for lightweight mortars are the same as ordinary mortars or experiments.

2 Experimental results and discussion Form the test specimens according to the mix ratio in Table 2 and test the dry density, strength, thermal conductivity, shrinkage and other properties until the specified age. The test results are shown in Table 3 and H. No. Compressive strength MPa) Heat Conduction Coefficient Shrinkage Density Dry Density Compressive Strength Mortar 28d Compressive Strength Material Dry Density and Thermal Conductivity Table 4 Jiangsu Province Wall Energy-Saving Main Material Thermal Parameters Name Specification tom) Bulk Density kg/m3) Thermal Conductivity Heat Storage Coefficient Main Applications Area Clay Perforated bricks 240/19014000.587.92 Province sand bricks 24019001.1012.72 Province slag bricks 24017000.8110.43 Province fly ash fired bricks -16000.57.82 Xuzhou concrete double row of holes block 19013000.685.88 Province aerated concrete blocks 2507000.223.59 Province XPS board -350.030.54 Province fly ash silt S1-2 15500.39- Nantong fly ash silt S3-4 Table 5 Common external wall structure and heat transfer coefficient Wall material and Thermal conductivity wall structure Wall heat transfer coefficient ordinary mortar masonry light mortar masonry clay perforated brick 0.5820mm cement mortar + 240mm porous brick + 20mm cement mortar 2.431.9120mm cement mortar + 240mm porous brick + 20mm ZL glue powder Particle +5mm cracking mortar 1.361.18 fly ash sludge brick 0.3820mm cement mortar + 240mm porous brick + 20mm cement mortar 1.801.3720mm cement mortar + 240mm porous brick + 15mmZL rubber powder polystyrene particles + 5mm cracking mortar 1.261. 03 Aerated Concrete Block 0.2220mm Cement Mortar + 240mm Aerated Concrete Block + 20mm Cement Mortar 0.720.5520mm Cement Mortar + 240mm Aerated Concrete Block + 15mm ZL Adhesive Powder Polystyrene Particle + 5mm Anti-cracking Mortar 0.620.48 2.1 Mechanics Performance Wang Yudong et al. [6] proposed that furnace bottom slag can replace 15% of ordinary yellow sand to make mortar. The ratio of this experiment is to use furnace bottom slag instead of ordinary sand. As can be seen from Table 3, the 28-day compressive strength of lightweight sand insulation mortar is reduced by 50% compared with ordinary mortar, but by adding thickening powder and fly ash, the 28d compressive strength of the lowest group can also be It reaches 8MPa and meets the requirements of masonry mortars M5.0 and M7.5; the highest group has an intensity of 15MPa-20MPa. Taking into account the thermal conductivity and the cost of mortar, the proportion of mortar can be further optimized to reduce the amount of cementitious materials. Dosage.

The gray ratio and the amount of cement are the main factors affecting the compressive strength of lightweight thermal insulation mortar. It can be seen that the water-cement ratio changes from 2.25 to 1.0, the sand-cement ratio decreases from 4.5 to 1.7, the cement dosage increases from 200kgm3 to 410kgm3, and the strength of the mortar increases gradually, that is, the more the unit cement amount, the smaller the water-cement ratio group strength. The higher the 28d intensity, the largest group was 1.6 times higher than the smallest group.

2.2 density and thermal conductivity and light insulation mortar density of 1300kg/m3 Table 3 shows that with the sand-cement ratio increased, the density of lightweight insulation mortar gradually reduced.

Bottom slag as a lightweight aggregate instead of yellow sand, due to its own porous structure and low thermal conductivity, making it possible to prepare lightweight thermal insulation mortar with low thermal conductivity. The size of the thermal conductivity of a material is related to the structure of the material itself, and is related to the thermal conductivity and density of the visible material. It can be seen that the two curves are basically the same, indicating that the sample density is closely related to the thermal conductivity. Bulk density is a direct reflection of the porosity of the material. Since the thermal conductivity of the gas phase is usually lower than the thermal conductivity of the solid phase, the insulation material has a large porosity, ie, a small bulk density. In general, increasing the porosity or decreasing the bulk density will cause the thermal conductivity to decrease. It shows that there is a linear relationship between thermal conductivity and dry density of lightweight mortar within a certain range. However, there are many factors affecting the thermal conductivity of the material, and further research is required to explain it more accurately. The experimental results show that the thermal conductivity of the prepared lightweight thermal insulation mortar is 0.19W/m*K)4.25W/m*K), while the thermal shrinkage coefficient of 2.3 ordinary drying mortar can be seen from Table 3, the drying shrinkage of ordinary mortar is 0.06. % 0.08%, while the lightweight insulation mortar drying shrinkage rate is 0.06% state. 10%, the difference between the two is not great. With the sand-cement ratio increasing, the drying shrinkage rate decreased.

3 Matching application of lightweight thermal insulation mortar and new wall materials Table 4 shows the thermal parameters of the current wall-dominated materials in Jiangsu Province. Table 5 lists the three types of basic wall structures and their thermal parameters that are common in the current project. Taking into account the effect of masonry mortar on the heat transfer coefficient of the entire wall, the use of ordinary mortar and light was calculated separately. The overall heat transfer coefficient of the mortar masonry results show that: the common thermal conductivity coefficient of clay porous bricks is Elotex Yilaitai awarded 15 scholars of Harbin Institute of Materials Material School Newsletter June 2nd, Elotex Yilaitai and Harbin The School of Materials of the University of Technology co-sponsored the Elotex Yi Lai Tai Scholarship Award Ceremony of the Harbin Institute of Technology in 2007. A total of 15 students won the Elotex Yi Lai Tai Scholarship.

Dr. Wang Chunji, Elotex Asia Pacific Technical Manager Eileex, Elo-tex Yi Laitai China Senior Sales Manager Wang Ping, Elotex Yi Lai Tai China Human Resources Department Hu Songli, Elotex Yi Laitai Northeast Technical Sales Director Yang Zhenye, Harbin Chair Award ceremony. At the meeting, Yi Laitai introduced the company’s technical achievements and Li Renfu, party secretary of the Institute of Materials Science at the Industrial University, and deputy dean Yu Lin’s personnel policy. They interacted with the students.

0.58W/6rK) does not meet the requirements of heat transfer coefficient 6i567*K) specified by energy saving standards. If lightweight insulation masonry mortar is used, only 20mm thick polystyrene insulation mortar can meet the requirements of energy-saving standards. However, the use of ordinary mortar masonry is still not up to standard.

15mm thick polystyrene powder particle insulation mortar masonry, wall can meet the energy-saving requirements.

The wall itself can meet the energy saving requirements.

In summary, lightweight mortar masonry walls can increase the insulation performance of the entire wall by more than 20%.

The apparent density of ordinary masonry mortar is generally more than 1800kg/m89 and the thermal conductivity is 0.8W/m*K). 0w/m*K), the apparent density of lightweight insulating blocks is generally 450kg/m3450kg/m3 and the thermal conductivity is 6rK). If ordinary masonry mortar is used to masonry lightweight block walls, the difference in thermal conductivity between the two will make the whole masonry cold bridge, and the energy loss caused by the masonry mortar joints will be large, and the wall will also appear. Surface condensation, hollowing or even cracking, affect the use of the function and service life of buildings, but also restrict the promotion and application of lightweight blocks. Therefore, thermal insulation masonry mortars with thermal conductivity similar to lightweight blocks should be used. It is feasible that the lightweight energy-saving mortar masonry and plastering surface developed in this project can be used as the main energy-saving materials for the wall in Table 4.

4 Conclusion Use power plant bottom slag as mortar aggregate to prepare lightweight heat-insulated masonry mortar and lightweight heat-insulating mortar. Its strength grade is M5M10, dry bulk density is 1300kg/m3-4600kg/m3, thermal conductivity 6rK)i25W/m *K), performance indicators in line with national industry standards.

The lightweight insulation masonry mortar has the characteristics of light weight, heat preservation, low cost, convenient construction, etc., and is matched with the lightweight wall energy-saving leading material, which can effectively avoid the cold bridge.” Xu Fasong. The study of iron tailings and gravel in concrete Application of Commercial Concrete, 2006 1) P Duan Pengxuan etc. Application of Iron Tailings Sand in Common Dry Mix Mortars.Beijing Institute of Building Materials Science.

Jia Qingmei and so on. Research and Current Situation of Resource Utilization of Iron Tailings . Mining Engineering, 2006 Chapter 1 Yin Xiang. Study on Properties and Production Technology of Iron Tailings Dry Mixing Mortars . China Mortar, Fig. 3 Relationship between Thermal Conductivity and Dry Density of Lightweight Mortar 3 This project is a project of Jiangsu Provincial Department of Construction (JH7.1)