Navegando por Assunto "Mortar"

Agora exibindo 1 - 12 de 12

Acesso aberto (Open Access)
Argamassas para dessalinização de alvenaria mista de edifício histórico de Belém
(Universidade Federal do Pará, 2013-09-05) LOUREIRO, Alexandre Máximo Silva; SANJAD, Thais Alessandra Bastos Caminha; ANGÉLICA, Rômulo Simões; http://lattes.cnpq.br/7501959623721607; http://lattes.cnpq.br/8950586647715771
In the historical monuments of Belém structural masonry, along with the foundations and pillars, are responsible for supporting the building (VASCONCELLOS, 1979). These masonry are made of stone and solid bricks with lime mortar setting and can present various pathologies among which stand out the action of salt efflorescence and moisture. These two agents cause detachment of layers, mortar spraying, the appearance of cracks in masonry, and whitish appearance (HENRIQUES, 1994; CHAROLA, 2000). The research has as main objective the identification, characterization and attenuation of salt efflorescence, through study of the masonry of the right transept of the Church of St. Alexandre, located in historic downtown of Belém- PA. For this, laboratory techniques were used in order to understand the favorable process conditions of salt efflorescence, the damage to the materials, the kinds of salts and which materials are effective for desalination. First was the mapping the masonry and mapping damage to verify the current situation and the most degraded areas. Was subsequently performed the physical, chemical and mineralogical characterization: 1) physical characterization by sieve analysis, trace analysis and analysis of the moisture content of the masonry, 2) chemical characterization through qualitative and quantitative testing of salts and 3) characterization mineralogy by X-ray diffraction. The X-ray diffraction was also used to evaluate the efficacy of four types of desalination mortars containing clay (bentonite and kaolin) and sand in different ratios. At the end of the study it was found that the suggested techniques for characterization and mapping of the masonry proved efficient and aided in the correct diagnosis of the existing problem. Moreover, the research showed which kinds of mortar are recommended to desalination of masonry damaged by salt efflorescence.
Acesso aberto (Open Access)
Comportamento de argamassas de revestimento quanto à retração, fissuração e mecanismo de descolamento em substratos de concreto
(Universidade Federal do Pará, 2013-10-22) LIRA, Mariana Domingues von Paumgartten; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
This research aims to evaluate the retraction, by the mortar superficial movement, occurrence of cracking and detachment of the mortar. Were choosed two types of substrate, one with a 30 Mpa resistance and other with 40 MPa resistance, also were used two types of mortar, one with additive and other lime based, two thicknesses of coating layer, from 15 mm and 30 mm, and was simulated the exposure condition that the region has.For this, tests were performed to characterize the mortar in the fresh state (consistency, water retention, air entrainment and mass density) and in the hardened state (compressive strength, tensile strength in bending, specific gravity, water absorption, voids and density). After preparation of the samples for evaluation, were taken the measures of superficial movement of the mortar for 28 days and the occurrence of cracks and detachment, as well as the verification of the bond strength of the coating and also the loss of water by evaporation of mortars. As a result of this research, it was observed that the variation of the resistance of the substrate analysis not showed a significant difference in the shrinkage, as well as the thickness of the layer to some series. It was also found that the type of mortar, or the material composition, has a direct influence on retraction. With regard to water loss by evaporation from the mortar, it can be seen that the additive achieved greater success in water retention materials. In the test of bond strength, was found that the most significant influence was in relation to the composition of the mortars and that they had values above the minimum allowed by regulatory norm.
Acesso aberto (Open Access)
Influência da substituição parcial do cimento por sílica ativa nas propriedades de argamassas com agregado reciclado de concreto.
(Universidade Federal do Pará, 2023-04-13) CRUZ, Welington de Sousa; CORDEIRO, Luciana de Nazaré Pinheiro; http://lattes.cnpq.br/9126233381230999; https://orcid.org/0000-0001-7931-4042
The main objective of this dissertation is to evaluate the effect of partial replacement of cement by silica fume on the physical-mechanical behavior of coating mortars with recycled concrete aggregate (RCC) and to analyze its environmental impacts, considering CO2 emissions and energy consumption. generated in the production of mortar raw materials. We tried to evaluate the influence of recycled aggregates in proportions of 1:3 and 1:4 (in mass) by partially replacing the natural aggregate with 0%, 30% and 50% RCC, and each of these groups was subdivided with substitutions partial cement by silica fume in the contents of 0%, 5%, 10% and 15%. The results allow concluding that the increase in the recycled aggregate content in the mortars impacts on its rheology and reduces its mechanical properties compared to the reference one, being softened with the incorporation of silica fume. Regarding environmental impacts, cement was the main cause of impacts. Samples R0S15 present the highest cement consumption in both the 1:3 and 1:4 mixes and, therefore, generate greater impacts. However, the impacts generated per unit of resistance show an inverse situation. Therefore, despite generating higher CO2 emissions and energy consumption, their contribution to resistance reflects greater sustainability.
Acesso aberto (Open Access)
Influência de aditivo polimérico no comportamento mecânico e reológico das argamassas produzidas com rejeitos industriais
(Universidade Federal do Pará, 2015-05-12) SILVA, André Luis Mileo Ferraioli; FELIPE, Augusta Maria Paulain Ferreira; http://lattes.cnpq.br/8871741271063047; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968
Mortars are considered to be particulate systems in suspension with fine aggregate, binder, water and organic polymeric additive. Factors such as granulometry, cement, ash and additive contents in their composition influence mortar properties in both the fresh and hardened states. A rheological study and mechanical test were performed on mortar prepared for floors and coatings through incorporating civil construction wastes (RCC) such as fine aggregate and fly ash, a mineral waste derived from combustion in boilers at the HYDRO ALUNORTECompany. This study seeks to develop a polymeric mortar that uses CPII E-32RS Portland cement andflyashas binders and fine sand and RCC with polyvinyl acetate (PVA) as aggregates. A study was performed on the influence of cement, ash, granulometry of aggregates and use of PVA based-polymeric additives on mortar properties.The materials were submitted to physical and chemical characterization using granulometric analysis, X-ray fluorescence and FTIR. In preparing the specimens, 6 formulas with 5% cement and 3 formulas with 10% cement were used, both with different levels of ash, sand and RCC andmaintaining a constant level of Portland cement content. A comparison of the mechanical and rheological properties of formulas with and without PVA was also made.Formulas in a fresh state were submitted to rheological tests. After 28 days of curing specimens of these formulas, by then in a hardened state, were submitted to tests for mechanical resistance to compression, specific mass, apparent absorption and apparent porosity. The research demonstrated that employing a PVA-based polymeric additive improved the mechanical properties of the mortar prepared with industrial wastes, as well as guaranteeing satisfactory rheological behavior for possible applications of such mortars in civil construction.
Acesso aberto (Open Access)
Influência do resíduo do caulim tratado termicamente da região Amazônica e o seu potencial uso como material suplementar ao cimento Portland.
(Universidade Federal do Pará, 2022-11-23) SOUZA, Márcio Rodrigo Nunes de; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
Mineral industries produce waste in large quantities and in different types and levels of danger, such as the kaolin processing industry, which produces waste based on silica, mica and kaolinite. The disposal of this material in an inappropriate place causes a strong environmental impact, which could be minimized with the use of this waste as raw material for use in civil construction. This work aims to study the incorporation of calcined kaolin residues as a supplementary material to cement and concrete for use in civil construction. In this research, kaolin residues from the Felipe mine located in the south of Amapá were used, being carried out physical, chemical and mineralogical characterization tests, the pozzolanic activity index of the calcined residues at temperatures 500ºC, 700ºC and 900ºC, as well as the analysis heat, according to ABNT standards. For the mechanical technological tests (Simple compressive strength tests, modulus of deformation and tensile strength by diametral compression) and durability (Water absorption tests by immersion and water absorption test by capillarity), were incorporated with 0%, 10%, 15% and 20% of calcined kaolin waste, replacing part of the Portland cement. The results obtained showed that the calcined residues presented high pozzolanic activity at a temperature of 700ºC, the use of calcined kaolin residue presented mechanical behavior and durability as a supplementary material to cement and concrete within the ABNT norms, and finally we concluded that there is viability technique of using waste for use in civil construction as a supplementary material to cement, as well as use for high-strength concrete.
Acesso aberto (Open Access)
Influência do teor de cinza volante na reologia de argamassa de assentamento: fabricado com reciclagem de resíduos
(Universidade Federal do Pará, 2014-02-05) CARDOSO, Dilson Nazareno Pereira; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968; FELIPE, Augusta Maria Paulain Ferreira; http://lattes.cnpq.br/8871741271063047
The mortars may be considered as a set of solid suspended particles (aggregate), water and binders (cement slurry). Thus, rheological behavior during cure can be influenced by factors such as particle size, composition and content of corporate water. This study investigated the rheological properties of six mortars, depending on the content of fly ash as a pozzolanic activity material, partial replacement of cement. This type of cement used as an aggregate base construction of the residue (RCC) which was characterized by diffraction and fluorescence X- rays. Were formulated for the mortars with addition of rheological tests residue construction (RCC) in proportions of 95, 90, 85, 80, 75 and 70% fly ash (CV) 0, 5, 10, 15, 20 and 25 % to 5 % of ordinary Portland Cement (PC - II and 32), and in each sample was incorporated 35 % water. We used the model VT 550 viscometer with sensor type coaxial cylinders SV1 - Haake temperature of 28 ºC. To evaluate the curing time of the material has scheduled a constant shear rate 53.4 s-1 for 1h and 45 min, with rated torque at intervals of 15min. For the development of flow curves and hysteresis curves, we used the shear rate between 0 and 600 s-1 in the time interval of 120 s. The results showed that the incorporation of fly ash is the main factor for increased torque on the curing time of mortar and behavior change reópetico for thixotropic, the traits analyzed. The experimental data of the proposed formulations are adjusted to the rheological model of Herschel - Bulkley.
Acesso aberto (Open Access)
Influência do uso de resíduos industriais nas propriedades mecânicas e reológicas de argamassas utilizadas na indústria da construção civil
(Universidade Federal do Pará, 2019-03-21) CARDOSO, Dilson Nazareno Pereira; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/1711061955509303
The general objective of this work was to develop alternative and usable materials within the construction industry, addressing a logic of recovery and reuse of solid waste, generated from construction and demolition construction sites, as well as the reuse of waste generated from the construction industry mining industry and mineral processing. Were used in the work the residue of construction (RCC), residue of sulfide copper ore (RMCS) and the waste of circulating fluidized bed boilers from the combustion of coal to fly ash (CV). The samples of these materials showed appropriate characteristics, such as recycled fine aggregate within the NBR 7211 standard. The materials were subjected to physical and chemical characterization through laser particle size analysis, x-ray fluorescence (FRX), diffraction and x-ray (DRX).). The mortars produced were studied in the free state, that is, without additives and also within the insertion of polymeric organic additive polyvinyl acetate (PVA) and Styrene Butadiene (SBR). The obtained mortars were physically characterized through the analysis of apparent porosity, water absorption, apparent specific mass and resistance to axial compression. Thermal analyzes of (TG and DTG) and scanning electron microscopy - SEM were also performed. In the fluid state rheological tests were performed to evaluate its behavior according to time (thixotropy), workability and the most representative rheological model for its flow. The developed materials presented technical properties approved by the ABNT standards, making them suitable for certain types of applications, in terms of laying and covering of walls, floors and ceramic tiles, respecting the technical characteristics of these materials.
Acesso aberto (Open Access)
Reciclagem de resíduo a partir de cinzas de carvão mineral: produção de argamassas
(Universidade Federal do Pará, 2001-07-06) SIQUEIRA, Jacilene Siqueira de; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968; SOUZA, Célio Augusto Gomes de; http://lattes.cnpq.br/0800747860976046
This work aims to evaluate the possibility of use of waste obtained from the combustion of coal in fluidized bed boilers, an alumina refinery in Pará state. In this context, we evaluated the incorporation of fly ash as pozzolan, to partially replace cement in mortar production. To that end, samples were prepared using Portland cement type CPII-E-32. The mixtures were in the ratio 4:1, that is 4 parts aggregate (silica) and 1 part of binder (cement and ash), with the inclusion of the ash of 10, 20, 30, 40 and 50 percentage with respect to the cement, beyond the mortar without addition. We defined two relation water / binder, 0,4 and 0,8. After 7 and 28 days curing time, were tested for compressive strength analysis of behavior. In addition, the mortar with the water / binder 0.8 were subjected to further analysis of X-ray diffraction, scanning electron microscopy, water absorption, porosity and bulk density, the results obtained were consistent when compared with literature data, showing that viable application of ash studied in the construction industry.
Acesso aberto (Open Access)
Reciclagem de resíduos industriais na fabricação de argamassas e placas cerâmicas premoldadas fabricadas a partir de matriz sílico-aluminosa destinadas a construção civil
(Universidade Federal do Pará, 2014-05) CARVALHO, Ronaldo Nonato Ferreira Marques de; MACÊDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968
It is proposed to manufacture plates in structured network of PVC pipes, filled with mortar composed of rejected materials of civil construction, and coal fly ash, hydrated lime and Portland cement, inspired by the traditional technique of earth construction called “taipa de mão”, employed in the State of Pará, Brazil. The final product is a contemporary and ecological construction system for the execution of partition panels, aiming the decrease and the reuse of waste construction’ materials, whose disposal causes environmental damage. The rejected materials have physical-chemical characteristics which allow its recycling, increasing the duration of their Life Cycle. Aiming to develop mortar’s material having characteristics as plasticity, elasticity and mechanical strength were made experiments with traces consisting of construction waste and Portland cement, duly processed and dosed for the confection of test bodies. These were submitted to the tests absorption of water, porosity, density, compressive strength and toughness, resulting in the selection of the most appropriate compound, in respect to use in manufacturing mountable ceramic plates for use in partition panels. The plates were submitted to the tests of compression and tension.
Acesso aberto (Open Access)
Rejeito do minério de manganês como material de construção civil
(Universidade Federal do Pará, 2017-06-02) VIVEIROS, Danielle de Cássia Santos de; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
The increasing global demand for manganese ore and environmental impacts associated with the disposal of ore waste have motivated studies about the reuse of materials from tailings dams. In this context, the main objective of this work was to study the reuse of manganese waste as materials for civil construction. For this purpose a characterization of the Mn tailings was made from a physical, chemical, mineralogical, environmental and reactivity point of view. From these analyzes, feasible applications for the tailings were investigated. The first one was to study its reutilization as a filler in Portland cement. For this, reference mortars and mortars with 6, 8 and 10% substitutions were made to the cement. The mortars were tested for compressive strength and total water absorption and voids index at 28 days. The tests showed that the mortars with substitution contents obtained positive results when compared to the reference mortars. Inducing the resistance gain mainly for the percentages of 6 and 8%, as well as for the results of total absorption and voids index. A second investigation was carried out to study the reuse of Mn tailings as a fine aggregate in the manufacture of concrete. For this purpose, reference concrete and concretes were made with 15, 20, 25 and 30% substitutions to the natural fine aggregate. Through the analysis of resistance to axial compression a positive result was observed for both samples, especially for concretes with 15 and 20% substitution. The tests of tensile strength and modulus of elasticity achieved satisfactory results for both samples, especially for concretes with 20, 25 and 30% of substitution. In the capillary absorption analysis, the concretes with substitutions presented significant variations when compared to the reference concretes. The samples of 15% and 30% were the ones that less absorbed water, and the results of the 20 and 25% samples were still below the absorption values of the reference concrete. In this way, the reuse of this waste as materials for civil construction becomes feasible from a technical and environmental point of view.
Acesso aberto (Open Access)
Resíduo do lodo da estação de tratamento de água da Região Metropolitana de Belém em substituição parcial ao cimento Portland em argamassa
(Universidade Federal do Pará, 2019-04-25) CUNHA, Bruna Baia da; PICANÇO, Marcelo de Souza
As a result of the growth of cities and the greater demand for quality of life, the demand for drinking water has increased in recent decades. Like any industrial process, the production of water for human use generates large quantities of by-products, being the main designated residue of waste, sludge or sludge of Water Treatment Station (WTPS). So far, the most common destination for the WTPS is the watercourse, although it is considered a solid waste. These factors motivate research aimed at alleviating the problems caused by incorrect waste disposal in the environment. In this sense, the present paper presents an alternative proposal for the disposal of WTPS in mortar, partially replacing cement, whose extraction and employment also cause environmental impact. The WTPS was used in the mortar with the least possible alteration of the residue, that is, its in natura use to avoid energy expenditure and to enable its use. The characterization of the materials used, as well as the physical, chemical, mineralogical and thermal characterization of the sludge extracted from WTP Bolonha, located in the metropolitan area of Belém, was carried out. The analyzes provided data that were the basis for investigations of viable applications for the residue. The first investigation studied its use as pozzolan in Portland cement, for which the tests that analyzed its potential reactivity with lime and cement were carried out. The investigation of the pozzolanic activity, both with lime and cement CP II-F-32, showed that mortars with replacement contents obtained lower results than required by the respective standards, discarding their use for this purpose. The second research analyzed the effects of the use of the residue as a filler in Portland cement, the reference mortar (without addition of sludge) and traces with additions of 6, 8 and 10% were used. In the compressive strength the 6% replacement content of the cement Portland CP I-25 by WTPS produced a resistance increase of 8,93% at 7 days and 3,24% at 28 days of age, in relation to the reference mortar, besides absorbing 7,81% water less than conventional mortar. Although the use of sludge occurs in small quantities, its use is feasible, since its incorporation will reduce the consumption of the raw material required for the production of mortar.
Acesso aberto (Open Access)
Restauração do concreto aparente: estudo tecnológico para salvaguarda de edificações com tendências modernistas
(Universidade Federal do Pará, 2013-03-21) OLIVEIRA, Djanira Cabral Viégas Borges da Cruz; PAES, Isaura Nazaré Lobato; SANJAD, Thais Alessandra Bastos Caminha; http://lattes.cnpq.br/8950586647715771; http://lattes.cnpq.br/3432832117667434
Concrete is basically formed by mixed cement, water, sand and stone, and has emerged as a building material to replace wood, stone, brick and even structural steel, but only in the twentieth century its aesthetic beauty was recognized. The modernism appropriated the new constructive technology and its plastic possibilities and splited definitively with the passed styles. Influenced by the schools of Rio and São Paulo, architects and engineers who built at Belém left a legacy of unfinished concrete constructions, which unfortunately is being threatened by the lack of specific care, since many interventions are made in a random and misguided way. Therefore, the aim of this research is to study the unfinished concrete under the historical and technological aspects in order to develop a methodology for restoration of areas with gaps, considering aspects such as color, texture and strength, seeking a compatible material to the original concrete. The study was conducted in three different steps: 1) Historical Research, 2) Field Research; 3) Research Laboratory. The materials of this study correspond to samples collected in three buildings and laboratory samples. The physical characterization of the samples allowed to find the approximated trace of the old concrete of 1:3 and the strength of the material, which is approximately 22MPa. The chemical and mineralogical characterization indicated that the original material has been suffering process of mineralogical transformation evidenced by the presence of polymorphs of calcium carbonate (CaCO₃) and allowed to understand that the aggregates used in the composition of the material may have quartz or gravel origin. It was also observed that the color and texture of the material varies depending on the type of cement and aggregate used in the production of concrete. From the identification of the principle features of the original materials was developed a methodology for producing a mortar for restoration with properties similar to the antique material. The results as color, texture, and strength were satisfactory, because the values established by rule were accomplished and were also compatible to the appearance of the original concrete, allowing restoring the image of the building and achieving the proposed objectives.