Português Influence of foaming additive dosage on the strength of foamed cellular concrete

Abstract

The work addresses the influence of the air-absorbing additive on the composition of foamed cellular concrete and evaluates, through specific tests, its impact on the properties of mechanical compressive strength, specific mass, and water absorption. The methodology initially adopted involved bibliographic research on the concepts of concrete, its technological evolution, and subclasses such as cellular concrete. Subsequently, tests and trials were conducted in the Materials Laboratory of the Civil Engineering course at the Catholic University Center of Santa Catarina. For this, four different formulations of cellular concrete were produced, varying the percentage of foaming additive, and 15 specimens were molded for each formulation for tests performed at ages of 7, 14, and 28 days, totaling 60 specimens. The CC01 sample, with the lowest amount of foaming additive incorporated, exhibited the highest compressive strength at all ages, measuring 8.85 MPa at 28 days, the highest density at 1511 kg/m³, and the lowest percentage of water absorption at 17.42%. Conversely, the CC04 sample, which contained the highest amount of foaming additive, presented the lowest compressive strength at all ages, with a measurement of 0.29 MPa at 28 days, the lowest density of 545 kg/m³, and the highest percentage of water absorption at 72.63%. The CC01 and CC02 specimens, achieving compressive strengths of 8.85 MPa and 5.55 MPa, respectively, comply with the standards required for application in civil construction for concrete walls cast on site. The amount of foaming additive significantly influenced the results of this study due to the increase in the void index within the samples.