123 American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS) ISSN (Print) 2313-4410, ISSN (Online) 2313-4402 © Global Society of Scientific Research and Researchers http://asrjetsjournal.org/ Soil-Cement Bricks as an Alternative for Glass Waste Disposal André Luiz Machado a , Roselene Maria Schneider b* , Adriana Garcia do Amaral c , Rafael Soares Arruda d , Flávio Alessandro Crispim e , Karinna Pinheiro de Oliveira f , Jennifer de Souza Onetta g , Letícia Tamara Hoffmann h a,b,c,d, f,g,h Universidade Federal de Mato Grosso – Câmpus Sinop, Av. Alexandre Ferronato, 1200, Distrito Industrial, Sinop, 78576-267 - Brasil e Universidade do Estado de Mato Grosso – Unidade Sinop – Avenida dos Ingás, 3001, Jardim Imperial, CEP 78555-000 - Brasil a Email: alm281082@yahoo.com.br, b Email: roselenems@yahoo.com.br, c Email: adrianagamaral@gmail.com, d Email: rafael.soares.arruda@gmail.com, e Email: flavio.crispim@unemat.br, f Email: karinna.p.o@gmail.com, g Email: jenny_onetta@hotmail.com, h Email: lthhoffmann@gmail.com Abstract Glass can be recycled an infinite number of times. However, the reverse logistics of bottles, flasks, packaging and others is not always economically feasible, and landfill disposal is widespread in Brazil. The reuse of glass waste is an alternative to recycling, hence the objective of this study was to evaluate the production conditions of soil-cement-glass bricks. The use of glass waste occurred in two ways, one with a cement substitute (glass powder) and another with a soil substitute (crushed glass), in the manufacturing of soil-cement bricks. The results indicated that the glass powder was ineffective in replacing cement. On the other hand, the incorporation of crushed glass significantly improved the mechanical resistance in the specimens. The soil-cement-glass bricks (mass composed of 45% soil, 45% ground glass and 10% cement) molded in conventional and alternative forms showed resistance to the compression established by standards at 14 and 7 days, respectively. This study demonstrated that bricks produced with crushed glass have advantages from the environmental and technical points of view, contributing to the sustainability of the industrial and civil construction sectors. Keywords: Waste incorporation; Reuse; Ecological Brick. ------------------------------------------------------------------------ * Corresponding author. American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS) (2020) Volume 71, No 1, pp 123-135 124 1. Introduction The growth of the global population causes an increasing waste generation, which makes it difficult and expensive to treat and set up its disposition. Waste reuse is a significant action to minimize such problems. The increased costs with raw materials and its reduced availability compels the search for alternative sources of it in the waste and byproducts from many processes and activities. It turns waste reuse into an important tool to sustainable development and environmental conservation [1]. Moreover, they help avoid and postpone waste disposal, as well as reduce problems, such as floods usually caused by the obstruction of drainage systems, and preserving natural raw material reserves. Civil construction generates large amounts of all sorts of waste, besides being responsible for a high consumption of natural non-renewable resources [2]. However, this sector has great potential to absorb solid wastes. Therefore, reclycing waste into aggregates or other components is an important alternative to reduce environmental impacts and to improve preservation. The number of research papers focused on reusing the waste from human activities in construction sites is growing [3,4,5,6]. Results about assessing crushed brick performance as supplementary material in recycled concrete aggregates stabilized with cement have shown that mixtures stabilized with up to 50% crushed bricks as supplementary material and with 3% cement presented appropriate physical properties and resistance consistent with requirements for the highway network [7]. With regard to specific waste such as glass, in Brazil data provided by ABRELPE [8] highlight that glass production reached approximately 3,000 t in 2008; 1,292 t of this total were produced by the packaging sector and 1,280 t by the flat glass sector. The disposal of approximately 20% of the produced packages take place in landfills or some other unknown locations. There is proven feasibility [9] concerning the use of glass waste in different replacement processes (and tested as a large or small aggregate), as well as a cementing agent in bricks, plaster and concrete. Glass from TV tubes and screens has considerable intrinsic strength; it absorbs water and is silica rich. The substitution of sand or pozzolan for glass waste in construction materials is possible, since the characteristics of glass make such substitution feasible [10]. Glass can be a great fine aggregate (sand) replacer in concrete manufacturing, i.e., glass-concrete is more resistant to compression than the standard sample [11]. However, an addition of more than 10% of glass into concrete is susceptible to the expansion of the mixture. Other studies showed that glass addition increased the compression strength by 16%, and the concrete flexion resistance by 14% [12]. Glass waste can be applied to manufacturing ceramic glazes, because glass addition leads to a product with aesthetical and mechanical features similar to the standard glazes, which makes ceramic surface water proof, colored and bright [13]. Besides plasters, bricks and concrete, soil-cement bricks are another alternative to waste disposal. Soil-cement bricks are a soil-cement mixture, and their manufacture is easy, since it occurs through manual molding and it requires neither burning nor expert professionals in its production and use [14]. There are literature reports of waste incorporation in soil-cement bricks. Incorporation of paper and cellulose waste in soil-cement bricks demonstrate that the incorporation meets the normative requirements in terms of compression strength and water absorption [15]. The addition of coconut fiber powder, rice husk and brachiaria bark to soil-cement bricks suggests that the mechanical resistance and water absorption properties are not affected if some of those vegetal wastes substituted cement up to 10% [16]. Results from the use of waste from water treatment plants into soil-cement bricks showed that it helps to reduce the environmental impacts of the water treatment plants [17]. The addition of used foundry sand together with gravel dust reduced water absorption and provided an acceptable level of mechanical resistance, in American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS) (2020) Volume 71, No 1, pp 123-135 125 accordance with established soil-cement standards [18]. In this work we examined the feasibility of recycling glass for the production of soil-cement bricks. We used ground glass as a replacement for cement, and powdered glass as a soil replacement, in the making of soil-cement bricks. It is environmentally reasonable by the use of recycled materials to replace natural resources, contributing to greater sustainability of building materials. 2. Material and methods The materials used in this research were soils (Red latosol and Yellow latosol), glass waste and Portland cement. There were two kinds of experimental steps. In the first one, we replaced part of the cement with glass powder; in the second one, we tested replacing the soil with crushed glass. 2.1. Glass waste The used glass was waste of flat glass, obtained from a glazing company located in northern Brazil. It presented big pieces (1 to 20 cm) and it was necessary to ground and sieve into two particle sizes: glass powder (smaller than 0.045 mm) and crushed glass (0.425 to 2 mm). The replacement of cement mass with glass powder to produce test specimens occurred in order to test a possible pozzolanic effect. Cement replacement with glass powder consisted of the following rates: 0, 25, 50, 75 and 100%. Crushed glass replaced soil in test specimens and bricks manufacturing. Soil (red latosol) replacement with crushed glass followed a 50% ratio, in mass. The granulometric crushed glass ranged from 0.425 to 2.00 mm, which corresponds to the mean and gross sand granulometry, since most of the sand in the red latosol was fine sand. According to the technical recommendations, granular soils have a stronger ability to gather with cement [19,20]. 2.2. Physical properties At Table 1 we can see the physical properties of the soils and soil-waste samples. The classifications of soil and soil-waste mixtures occur by granulometric assays and consistence limits (liquid and plastic limits). Soil and soil-waste were classified by comparing these results to results recorded by the National Transportation Infrastructure Department – DNIT [21] that uses the Transportation Research Board (TRB) classification. The Brazilian Portland Cement Association [22] recommends the TRB system. TRB gathers soil groups and sub- groups based on granulometric features and workability. The soil and soil-waste texture are presented in Table 1, based on the NBR 7181 [23] and sand, silt and clay contents. 1 [25]; 2 difference between LL and LP [26]; 3 [27]; 4 AASTHO-TRB adapted from ABCP [22]; 5 based on the TRB classification. * Proportion of ground glass that attributes the best texture characteristics to the soil that receives cement, according to the TRB Classification. American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS) (2020) Volume 71, No 1, pp 123-135 126 Table 1: Physical properties of the soils and soil-waste samples Parameter Soils, waste and mixture types Red latosol Yellow latosol Crushed glass Red Latosol (50%) + crushed glass (50%)* LL 1 % 17 33 -- 17 IP 2 % Non-plastic 13 -- Non-plastic Maximum Dry Unit Weight, kN m 3 18,96 15,44 - 19,40 Optimum Moisture Content 3 % 12 21 -- 10 TRB classification 4 A-2-4 A-6 -- A-1b Optimum cement 5 % mass 7 12 10 Total sand % 68 27 100 84 Mean and Coarse sand (0.425