Papers by Keyword: Expanded Perlite

Abstract: Expanded perlite as an aggregate in concrete may make insulating concrete and fire-resistant suitable for roof decks and other purposes. Expanded perlite aggregate (EPA) may be used with gypsum plasters and Portland cement to protect columns, beams, and external applications. Other building uses are chimney linings, under-floor insulation, ceiling tiles, gypsum boards, and roof insulation boards. The primary goal of this research is to learn more about the effects of employing perlite aggregate (EPA) as a partial or complete substitute for sand on various characteristics of expanded perlite concrete (EPC) at 7 and 28 days. Air-dry density, compressive strength, water absorption, flexural strength, and thermal conductivity are all investigated in this research. EPA replacement by volume of sand was used to create five EPC mixes with 0%, 25 %, 50 %, %, and 100%. The effects of introducing 0.5% polypropylene fiber on the characteristics of EPC mixes were investigated. To increase the EPC workability, superplasticizer was utilized, particularly at the higher EPA replacement levels. The test outcomes reveal that the measured mechanical and physical properties of EPC decrease when increasing the EPA content. Thermal insulation of EPC increases with increasing the percentage of perlite aggregate replacement. In addition, using polypropylene fibers in the EPC specimens cause a slight reduction in density, compressive strength, and thermal conductivity compared to unreinforced specimens. Polypropylene fibers significantly increase in modulus of rupture reach 29% at 28 days, and increase in water absorption compared with unreinforced specimens.

Abstract: The insulation wall provides suitable heat for winter production of solar greenhouse. A thermal insulation mortar containing paraffin/expanded perlite composite phase change material based on desulfurized gypsum was studied as an inner insulation mortar to improve heat preservation and storage/exothermic capacities in solar greenhouse walls. Results showed that the ideal mass ratio of paraffin and expanded perlite was 60:40. The phase change temperature of the paraffin/expanded perlite composite particles was 25.3 °C, and the latent heat was 122.3 kJ/kg. The ideal mass ratio of this composite phase change material and desulfurized gypsum was 1:3. The ideal mixing amounts of dispersible polymer powder, redispersible latex powder, citric acid, hydroxypropyl methyl cellulose ether, and polypropylene fiber were 2%, 0.15%, 0.5%, and 0.5% of desulfurized gypsum content, respectively. The prepared composite phase change thermal insulation mortar had a dry density of 363 kg/m³, a compressive strength of 0.73 MPa, a softening coefficient of 0.65, a coefficient of thermal conductivity of 0.076 W/m·K^-1, a heat capacity of 1.35×10³ J/kg·°C^-1, a heat storage coefficient of 11.65 W/m²·K^-1, a phase change temperature of 25.6 °C, and a phase change latent heat of 89.8 kJ/kg. The phase change temperature and the phase change latent heat were suitable for solar greenhouse production.

Abstract: Development of new material is focused on modification of properties of materials with silicate binder so that these could be used for renovation of horizontal structures of high-temperature devices and at the same time contribute to reduction of heat transportation of constructions with higher surface temperature (in this case 200 and 500 °C). Main requirements for this material is low volume weight and low coefficient of thermal conductivity. This paper assesses influence of exposition to higher temperatures on microstructure.

Abstract: The surface-vitrified and expanded perlite is a new, high-quality insulation materials. It is studied to the effects on performances of the glass surface to expanded perlite insulation board, through comparing with the openings of expanded perlite, expanded and vitrified small ball and surface-vitrified and expanded perlite. A large number of experiments have been done on the physical properties of the insulation board with surface-vitrified and expanded perlite. It shows that the insulation board with surface-vitrified and expanded perlite has a low density, high strength, low water absorption, high obturator rate, low thermal conductivity, stable performance and so on. And the main reason is analyzed.

Abstract: Flatwise compression and flexural behaviour of perlite/sodium silicate composites made of expanded perlite and sodium silicate is studied using a new manufacturing method for applications of sandwich foam core materials. Sodium silicate content in composites (a perlite particle size of 2-3mm) was varied for a range of 0.1 - 0.3 g/ml and compaction ratio for moulding for a range of 2.0 - 3.0. Specimens under flatwise compression were found to be more capable for energy absorption than those previously reported for lengthwise compression, ascribing to appearance of densification stage following the initial cracking. Also, under flexural loading, energy absorption in composites after the initial cracking was found to be in operation, supporting their candidacy for wide applications where gypsum boards are dominant. It was deduced from both flexural testing results and fracture mechanism that compressive strength is higher than tensile strength, suggesting the future directions of mechanical performance improvement.

Abstract: Degradation of building materials is an important phenomena influencing its design and utilization. Corrosion of concrete, due to common use of this material is especially important. Chemical corrosion of cementitous materials may be mitigated using various methods. Among them introduction of properly chosen active supplementary cementitous materials to the mix is one of most commonly used. One of possible additives possessing pozzolanic properties is ground waste expanded perlite. No data on the influence of such perlite on chemical durability of cementitous materials can be found in literature. Present paper presents results of investigation on the influence of ground waste expanded perlite on chemical durability of cement mortars. Results obtained showed that there is an improvement of durability of mortars modified with ground waste expanded perlite in sodium sulfate enviroment.

Abstract: This paper studied the produce process of the lightweight wall material (LWW). The main components of LWW were expanded perlite (EP) and Portland cement (PC). An experimental investigation was carried out to study the effect of EP on the performance of LWW, such as the bulk density, the strength property and thermal conductivity. The experimental results indicated that the products can be divided into lightweight structural materials and lightweight thermal insulation materials.

Abstract: In this paper, desulfurization gypsum was made of cementing materials and expanded perlite as light aggregate, by adding the right amount of fly ash and other admixture, in the pouring forming preparation of desulfurization gypsum heat preservation material. Expanded perlite is porous surface, made its hydrophobic, lower water absorption, by emulsion coated surface of expanded perlite. In the waterproof property research, different emulsion composite waterproof contents on the influence of the bibulous rate of the product volumetric had been studied, and emulsion composite waterproof agent was chosen as the last agent with the dosage of 4%. SEM test for analyzing the microcosmic structure of desulfurization gypsum products were taken to research and analyze each combination, and discuss the waterproof and thermal insulation mechanism. The optimal parameters of the desulfurization gypsum of insulation products obtained by the experiments were: desulfurization gypsum of 90%, fly ash of 10%, and fiber of 0.5%, emulsion composite waterproof agent of 4%.

Abstract: The expanded perlite lightweight, non-toxic, non flammable, good insulation properties, and chemical stability, corrosion resistance, low cost, its application more widely. But after absorbing its high water absorption and the freeze-thaw resistance shortcomings significantly reduced as building insulation materials, especially in the cold and cold regions is very restricted. Expanded perlite products with hydrophobic technology, the advantages of both ordinary expansion perlite products, but also solve the problem of absorbent easy and freeze-thaw resistance poor, as the application of external insulation materials in building engineering has been expanded.

Abstract: In this paper, expanded perlite / fly ash floating beads insulation material was made of expanded perlite, fly ash floating beads, cement, fly ash and VAE emulsion by adding decent additives, like waterproof agent, in the pressure forming process. The effects of molding pressure, VAE emulsion content, fly ash floating beads content and waterproofing agent content on the properties of thermal insulation material were studied, and the internal microscopic morphology of thermal insulation material was observed by SEM. Besides, the related action mechanism was explored. The test results show that the optimum ratio as follows: molding pressure of 0.46 MPa, VAE emulsion content of 20%, fly ash floating beads content of 20%, waterproof agent content of 7%.