Effect of Additives, Cement Type, and Foam Amount on the Properties of Foamed Concrete Developed with Civil Construction Waste

Abstract

The main objective of this study was to evaluate the use of additives in producing foamed concrete blocks, which were made by totally replacing natural sand with civil construction waste (CCW). The concrete blocks were developed in accordance with an experimental design that used the complete factorial statistical method, for which three factors with different levels were considered: cement type (CP-V, CP II-Z, and CP II-F); use of additive (without additive, plasticizer, air entrainment, and superplasticizer) and foam amount (5.7%, 7.7%, and 9.5% of the total mass). The influence of each factor and the interactions between them were assessed on the following response variables: compressive strength, dry and saturated density, air voids, water absorption, and thermal conductivity. The results show that all factors had a significant influence on the variable response. For example, the use of the superplasticizer additive resulted in higher compressive strength, lower density, lower air void, and lower thermal conductivity. Finally, the use of additives had little influence on the response variables in relation to the other factors.

Evaluation of the Physical and Mechanical Properties of Autoclaved and Foamed Concrete Blocks Marketed in Passo Fundo/RS Brazil

“…Figure 2 shows the experimental apparatus used to determine thermal conductivity, which was done by using a hot thermal wire on the surface. This technique has already been corroborated as a variant of the parallel hot wire by several authors (GRAZZINI;BALOCCO, 1995;AKIYOSHI et al, 2001;SANTOS, 2002;FRANCO, 2007;SACHT et al, 2010;LERMEN et al, 2019) and is characterized as being a direct method that detects the transient temperature. The experimental system consists of two multimeters to determine the electric current and voltage; two samples in the form of a parallelepiped; a hot wire (0.5 mm diameter kanthal) connected to a power source; four temperature sensors (NTC); and a data acquisition system.…”

Waste Reduction in Industry: A Study on Using Fine Green Foundry Sand Waste in Foamed Concrete Production

“…The thermal conductivity test was performed using the surface hot wire test. This technique has been used and described in detail in previous works, such as Lermen, et al [18], Sacht et al [19], Santos [20], and others.…”

Utilização do Resíduo de Areia Verde de Fundição no Desenvolvimento de Concreto Espumígeno

“…Como se esperava, as densidades diminuíram com o aumento da quantidade de espuma, pois aumentando a quantidade de espuma, aumenta a inserção de bolhas de ar no interior do concreto e consequentemente aumenta a quantidade de poros. Isso está de acordo com os estudos de Favaretto, et al (2017) e Lermen, et al (2019). Em relação ao percentual de substituição, pode ser visto que aumentando a susbtituição da areia natural pelo RAVF as densidades (seca e saturada) aumentam.…”

“…A Figura 8(a) mostra o gráfico de absorção de água em relação a quantidade de espuma visualizado, onde é possível visualizar que o aumento da quantidade de espuma adicionada aumenta a absorção de água. Segundo Gomes et al (2015) e Lermen et al (2019), esse fenômeno ocorre devido ao aumento da quantidade de vazios total e do aumento da conectividade entre os poros.…”