Plaster materials from waste calcium sulfate containing chemicals, organic fibers and inorganic additives (original) (raw)
Related papers
Journal of Cleaner Production, 2019
Gypsum is widely used in the construction sector in internal coatings. The fact that the chemical composition of gypsum does not change makes the material fully and eternally recyclable, potentially solving the important problem of the large amounts of gypsum waste that each year go to landfills. Up to now, most of the works that use gypsum wastes subjected the material to a previous heating process. This implies a significant energy consumption, reducing the environmental benefits of the recycling process. This paper shows the second part of a research on which two different types of gypsum waste were used as a substitute of commercial gypsum: gypsum waste from industrial plasterboard production and flue gas desulphurization gypsum from a thermal central plant. In this research, the influence of the heating process on the development of new gypsum plaster composites containing different types and contents of waste was studied. Their mechanical properties and thermal conductivity were determined and a brief environmental analysis, using the Life Cycle Assessment method, was carried out. Based on the findings of this paper, it is confirmed that it is possible to substitute 100% of commercial gypsum with gypsum waste from industrial plasterboard production without any heating treatment, but maintaining a good performance. With this action, apart from the benefits in terms of environmental impacts, a slight improvement in the density, mechanical properties and thermal conductivity of the plaster was obtained.
Hygric and thermal properties of lime plasters modified with wood chips ash-based mineral admixture
CENTRAL EUROPEAN SYMPOSIUM ON THERMOPHYSICS 2019 (CEST), 2019
Information on plasters hygrothermal performance is of the particular importance for their applicability, especially in such applications, where high moisture content of the substrate is anticipated. Among such applications belong above all historical and older buildings, where horizontal waterproof insulation is usually missing. Therefore, hygric and thermal properties of newly developed lime plasters modified with wood chips ash-based mineral admixture are studied in the paper. As wood chips ash is pozzolana active, in plasters composition, lime hydrate was partially substituted by wood chips ash coming from biomass incinerator for heat and electricity production. The replacement ratio was 5, 10, and 15 mass % respectively. The dosage of batch water was maintained similar for all tested plasters. For basic characterization of studied materials, their bulk density, specific density and total open porosity were measured. Among hygric properties, apparent moisture diffusivity, water absorption coefficient, saturation moisture content and water vapor transmission parameters were accessed. As heat transport and storage significantly affect plasters performance in a real environment, their thermal conductivity and volumetric heat capacity were measured. Since the total open porosity was almost similar for all tested plasters, and their hygric and thermal properties varied in dependence on lime hydrate substitution, additional pore size distribution measurement was performed for explanation of obtained data. Based on performed test and accessed data, wood chips ash was found to be an alternative eco-efficient mineral admixture applicable in plaster mix composition.
Study on Gypsum Plasters with Modified Waste Mycelium as Retarder
Proceedings of the 2015 International Symposium on Computers and Informatics, 2015
As new type of indoor decoration materials, gypsum plasters have good development prospect in fire resistance, heat preservation and insulation, environmental protection, etc. The purpose of this paper is to prepare gypsum plaster using desulphurization gypsum, waste mycelium retarder (WPM) and some additives. The formulation of surface gypsum plaster was obtained: desulfurization gypsum 93%, cement 2%, granulated blast-furnace slag 4%, water retention agent 1%, water reducing agent 0.05%, WPM retarder 0.06%. The base plaster was obtained by mixing surface gypsum plaster with medium sand in mass ratio of 1:1. 5. The thermal insulation gypsum plaster was prepared with surface gypsum plaster and perlite by mass ratio of 5:1.8. The products conform to (JCT517-2004) standards.
Journal of Building Engineering, 2020
The construction sector consumes 95% of the total production of gypsum due to its multiple applications. Gypsum plaster is one of the most common indoor coating material (pastes and mortars), but it can also be used in prefabricated products like plasterboards, blocks and decorative elements. Gypsum waste recycling provides a solution to an important environmental problem from the use of gypsum plaster, which is the generation of large amounts of wastes at different phases (production, construction, rehabilitation and demolition). This paper studies two different replacement alternatives of natural gypsum: Flue Gas Desulphurization (FGD) gypsum and gypsum waste obtained from industrial plasterboard production. The influence of the previous types, amounts of waste (25, 50, 75 and 100 wt%) and different heating temperatures (100 � C, 150 � C and 180 � C) and processes on the workability of gypsum plasters is evaluated and discussed, based on a microstructure analysis using XRD and SEM techniques. This research highlights the feasibility, in terms of workability, of using Gypsum Plasterboard Waste (GPW), without any heating process, as a replacement gypsum in plasters. Despite the fact that a higher amount of water was necessary in the production of the mixes, a good workability was achieved. On the other hand, the unfeasibility of using unheated FGD as a constituent of plasters was demonstrated. However, a good performance, in terms of workability, of the FGD was obtained when the powder was subjected to a heating process at 180 � C during 6 h.
Modified gypsum compounds: An ecological–economical choice to improve traditional plasters
Construction and Building Materials, 2012
h i g h l i g h t s " We studied hemihydrate-slag-pozzolanas pastes with improved performance than plasters. " The main hydration products are gypsum, ettringite and C-S-H. " Density is slightly higher than pure plasters but strength is almost triplicate. " Silica fume additions translate in excellent dimensional stability after 180 days.
A new calcium sulfate-based plaster composed of composite particles
Materials and Structures, 2014
Flash-calcination of gypsum by a new patented process produces a particular type of plaster. This particular plaster has been characterized and compared to a classical b-plaster. It appears as a stable mixture of hemihydrate and of c-anhydrite. Because of its composition, this new plaster presents several stable states depending on the storage conditions. A study of its reactivity followed by XRD and thermal analyses has been realized. It reveals that even after several months of exposition under moist atmosphere, c-anhydrite is still present in the sample. A model of composite particle of plaster is proposed for explaining this unusual behavior.
Construction and Building Materials
Abstract It is important to ensure indoor comfort by passive methods, avoiding mechanical equipment that has energy costs. To assess plasters common efficiency but also its contribution as moisture buffers, five different plastering mortars, including unstabilized and stabilized earth-based plasters, gypsum and cement-based pre-mixed plasters, were analyzed and their chemical, mechanical and hygroscopic characteristics compared. The materials and mortars were analyzed by X-ray diffraction and simultaneous thermal analysis. Linear shrinkage, dry bulk density, dynamic modulus of elasticity, flexural and compressive strengths, dry abrasion resistance, surface cohesion, surface hardness and sorption and desorption of mortars and plasters were also evaluated. The mechanical strength of earthen mortars is lower than gypsum and cement-based mortars. However, earth plasters show the highest hygroscopicity, acting as moisture passive buffers, improving thermal comfort and contributing to occupantś health.
Engineering, 2011
Since antiquity, man used to stock up materials and products existing in his close surroundings to build his house, which provides him shelter and comfort. Within the present work, mixtures of plaster and dune sand have been studied with the aim of valorization of locally abundant materials. The tests showed that with the addition of dune sand and the compaction, an optimal mixture (67% plaster and 33% dune sand) can be used as a carrier element for construction of up to three levels; since significant increase of the mechanical strength has been observed. The element obtained offers an acceptable thermal insulation with a decrease in the thickness of the outer wall construction. The use of this gypsum's mortar block as a carrier element in a structure not exceeding three levels, also enables a considerable savings especially in areas where sand and plaster are abundant and relatively inexpensive.
Thermal and mechanical properties of gypsum plaster mixed with expanded polystyrene and tragacanth
Thermal Science and Engineering Progress, 2017
In this paper, the employability of waste Expanded Polystyrene Foam (EPS) as filling material in the plaster with resin added gypsum by means of revaluation has been examined. After waste EPS is collected as packaging material and disintegration according to 0-3 mm particle diameters and mixed with the gypsum of percentages; 20%, 40%, 60% and 80%. Tragacanth is added to each of this binder at 0.5%, 1% and 1.5% of the weight of the mixture in order to create artificial pores on gypsum block. The samples of 16 different combinations are produces. They are subjected to some tests to find out their properties. It is found that; the thermal conductivity, the compression and tensile strength decreases with increasing amount of EPS and tragacanth in the mixture. Produced samples must not be used in external plaster which is subjected to water against the danger of freezing as the water absorption rate was found higher than 30%. With this study, it is recommended that the samples should be used as internal plaster, insulation plaster and decoration material due to their canal opening and paint sustention features. If this plaster and decoration material is used, (i) the waste EPS will be evaluated and environmental pollution will be prevented, (ii) building heating and cooling energy will be saved.
Influence of Wood and Plastic Waste as Aggregates in Gypsum Plasters
IOP Conference Series: Materials Science and Engineering, 2019
Large amounts of waste are generated each day in the world, being a major concern for the EU28, who establish waste management as a priority line of work within the Horizon 2020. Construction sector is one of the largest residues generators. In that sense, architects and civil engineers should give an answer to solve that environmental problem. One of the options is to reuse waste for the generation of new materials and products for construction. In this research, wood waste (sawdust) from demolition works and polycarbonate waste have been used as aggregates to generate new gypsum plasters. Different percentages of additions (5, 10, 20 and 40%) for each type of waste have been conducted to develop the gypsum composites. Physical (density and thermal conductivity) and mechanical (flexural and compressive strength) properties of the new plasters have been measured using the procedure regulated by standards, comparing them with the reference material values (commercial gypsum without a...