Concrete is one of the most important material for civil construction, given its high applicability. C Compressive strength (fc) is one of the main parameters to evaluate the concrete quality. Concrete of the same mixing volume may vary even with the same materials preparation. Concrete specimens molding, and its surface regularization contribute to these variations that are often hard to measure. Therefore, this paper aims to determine the variations in compressive strength of concrete, simulating different processes for casting, initial curing and surface treatment. In stage 1, the specimens were subjected to five surface treatment types, resulting in variations of 30% for concrete fc, whereas grinding specimens reached the highest 28-day compressive strength, so they were carried over to the next stage. In stage 2, specimens were produced as per ABNT NBR 5738 (2015) and with induced errors in casting and initial curing. The specimen produced according to the standard achieved the second-best result, whose 28-day fc was3% lower than that of the similar method, despite leaving the specimen uncovered for the first 24 hours after casting. Specimens produced in metal cylinder form works shows higher results than those produced in polyvinyl chloride molds (PVC).

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Em setembro de 2020 aconteceu a eleição da Sociedade Brasileira de Acústica referente ao biênio 2021–2022. O processo eleitoral aconteceu entre os meses de setembro e dezembro, de maneira totalmente remota. Foram eleitos a nova diretoria nacional, membros dos conselhos deliberativo e fiscal, bem como seus suplentes, além das diretorias regionais Norte, Nordeste, Centro-Oeste, Rio de Janeiro, São Paulo e Rio Grande do Sul. A plataforma de votação escolhida foi o Limesurvey, de custo reduzido e que propiciou segurança e confiabilidade ao processo de votação. O resultado da eleição foi homologado em Assembleia remota aberta a todos os associados.

The lack of control regarding waste generation is a problem still faced by the construction industry, whereas its inputs could be used in the production of new cementitious composites, maintaining the quality, performance and sustainability of structures. This study developed grouts through the substitution of natural aggregate for residues of crushed ceramic bricks, evaluating its fresh state and mechanical properties. The samples displayed loss of workability and initial slump in fresh state, besides loss of compressive strength, elastic modulus, total water absorption and capillary water absorption in hardened state. In addition, composites with grog presented less consistency in fresh state when compared to the reference sample. The differences were even greater over time. As for the hardened state, the compressive strength of the samples was similaramong them at both ages, and all results remained above 14 MPa at 28 days, as required by ASTM C476, hence being characterized as structural grouts for masonry. For the elastic modulus test, the results were higher for samples with lower amounts of waste due to less internal voids and higher volume of natural aggregates. The substitution of natural aggregate for civil construction waste (CCW) in the mixtures increased void ratio and water absorption, while causing the lowest specific gravities of the research. Overall, the sample that presented the most satisfactory values was CCW 25%, showing that it is possible to obtain benefits from waste produced in factories and buildings, even for higher replacement levels, occasionally

As cavidades em blocos de vedação diminuem a massa superficial do elemento e aumentam as ressonâncias internas nos blocos, prejudicando o isolamento sonoro. Para minimizar esse efeito, os septos dos blocos podem ser preenchidos com material poroso, criando um amortecimento interno das ondas sonoras. Um material com potencial para tal fim é a vermiculita expandida. Nesse sentido, o estudo buscou avaliar a influência da utilização de vermiculita expandida no preenchimento de septos de blocos cerâmicos em paredes de alvenaria para o aumento do isolamento acústico desses sistemas construtivos, por meio de ensaios de perda de transmissão sonora. Para tal, foram preparadas 12 amostras com blocos cerâmicos de geometrias distintas nas seguintes composições: sem revestimento, com revestimento de gesso e revestimento em argamassa. Além disso, para cada composição foram construídas amostras sem e com o preenchimento dos septos dos blocos com vermiculita expandida. O índice de redução sonora foi determinado seguindo os parâmetros da ISO 10140:2010, sendo os ensaios realizados em câmara reverberante de ruído aéreo do itt Performance da UNISINOS. Verificouse que o preenchimento dos septos dos blocos com 14 cm de espessura proporcionou um aumento no seu isolamento acústico de até 13 dB.