Analysis of the potential use of poly(acrylonitrile-co-butadiene-co-styrene) in autoclaved aerated concrete

Construction projects, from single-family houses to civil engineering works, depend heavily on the extraction, processing, and transport of building materials. Structural walls are most often made from wood, brick, and various concretes, including autoclaved aerated concrete (AAC). Intensive growth in construction and reliance on natural aggregates have led to excessive use of quartz sand from mines and riverbeds. Because river sand is widely used as fine aggregate in concrete, restrictions on its extraction in many regions have increased the demand for alternative fine aggregates, while strict environmental regulations complicate the disposal of industrial byproducts. Incorporating such byproducts as alternative fine aggregates offers a sustainable way to address both riverbed degradation and industrial waste management (Santhosh et al., 2021).

This article focuses on AAC modified with waste-based additives: ABS (poly (acrylonitrile-co-butadiene-co-styrene)) and basalt powder (BAZ). ABS regranulate is a recycled plastic derived from industrial waste. It is an amorphous, metastable polymer with high strength, stiffness, scratch and impact resistance, good insulating properties, and resistance to light and UV radiation, but with low resistance to acids, esters, and ketones (Dębska, 2011). Recycling of plastics is a key element of global waste management, yet its effectiveness varies widely: in the United States recycling rates remain low and uneven across states, whereas Europe has achieved higher overall recycling performance through stricter environmental policies (Siemienowicz-Jaszyna, 2023).

Within sustainable waste management, O-I conducted a life-cycle assessment (LCA) of glass in 2010, showing that glass can have a more favorable carbon footprint than aluminum or PET. In line with ISO 14040 and ISO 14044, LCA comprises four stages: goal and scope definition, life cycle inventory (LCI), life cycle impact assessment (LCIA), and interpretation of results (https://www.pakowanie.info/o-i.html; Polska Izba Opakowań eu.o-i.com, 2017).

At the same time, global consumption of natural aggregates and binders continues to grow. According to Science magazine and a 2021 UN report (Fritts, 2019), around 50 billion tons of sand and gravel are used annually in construction, with concrete production accounting for nearly 10% of global industrial water use. More than 4 billion tons of cement are produced each year, which further intensifies pressure on natural resources (Czyszczoń, 2023).

According to the United Nations’ 17 Sustainable Development Goals (SDGs) for 2030, rational management of natural resources, alongside poverty reduction, is a key global challenge and a condition for sustainable development. Analyses show that if these goals are met while global consumption follows patterns of developed countries, the use of resources (water, energy, aggregates) will continue to rise sharply, potentially triggering international conflicts and severe ecosystem damage. The example of China’s rapid economic growth demonstrates that such development, based on extremely high resource consumption and serious environmental degradation, cannot serve as a model for developing countries; instead, deep changes in the management of natural resources and resource-based services are required (Wennersten & Qie, 2017).

This article examines the modification of autoclaved concrete using ABS granulate and basalt powder. The design of masonry wall structures follows the guidelines of the Eurocode 6 package, which includes four standards: PN-EN 1996-1-1, PN-EN 1996-1-2, PN-EN 1996-2, and PN-EN 1996-3. The first and last standards define procedures for static and strength calculations, PN-EN 1996-1-2 provides guidelines for wall design under fire conditions, and PN-EN 1996-2 specifies requirements for design and execution (Dębska, 2011; Drobiec et al., 2016).

Cement concrete offers several advantages, including high compressive strength, resistance to elevated temperatures and fire, ease of use, and relatively low production cost. Within the framework of sustainable construction and particularly environmental protection, the reduction of natural aggregate consumption such as quartz sand, and sustainable waste management, construction materials, including conventional and autoclaved concretes, are increasingly subject to modifications aligned with these requirements.

Palos et al. (2011) investigated the modification of cement mortar using recycled acrylonitrile-butadiene-styrene (ABS) powder. They examined mixtures with polymer-to-cement ratios of 8 %, 15 %, and 25 % by weight, focusing on changes in compressive behavior and adhesion to steel reinforcement. Their compression tests showed an increase in Young’s modulus for mixtures containing 8 % and 15 % ABS. However, adhesion strength to steel rebars decreased after the addition of ABS. When ABS was treated with maleic anhydride, adhesion improved. The reduced adhesion observed in mortars with untreated ABS was attributed to disturbances at the cement-steel interface. Scanning electron microscopy (SEM) revealed changes in the hardened mortar microstructure and an increase in pore volume following ABS incorporation (Dobiszewska et al., 2018; Drobiec et al., 2016).

Similar modifications were applied to AAC, where 8 %, 15 %, and 25 % by weight of ABS were introduced into the raw mixture with a sand-to-cement ratio of 3:1. These studies reported increased compressive strength of the final product. The addition of ABS waste together with maleic anhydride further enhanced adhesion to reinforcing steel, an important factor in structural applications (West et al., 2013), although these results differ from those obtained by Palos (2011).

Basalt powder is a more widely used as an additive in concrete when compared to ABS. In his study, Unčík & Kmecova (2013) evaluated the effect of basalt powder added in quantities of 10 %, 20 %, and 30 % by weight as a cement substitute on the rheological properties of fresh cement mortars and the physical properties of hardened mortars. The consistency of fresh mortars was expected to correspond to that of a self-compacting material. Unčík examined the influence of basalt powder on initial consistency, workability loss, shrinkage, and compressive strength, and reported favorable outcomes (Dobiszewska et al., 2018; Drobiec et al., 2016).

The aim of this study is to evaluate the feasibility of using ABS regranulate and basalt powder as partial replacements for quartz sand in autoclaved aerated concrete, focusing on compressive strength and bulk density.

The research section of this article presents tests on autoclaved concrete samples modified with ABS (poly(acrylonitrile-co-butadiene-co-styrene)) and basalt powder (Fig. 1).

Fig. 1.

Samples of autoclaved concrete products modified with ABS and basalt powder (own research)

The article presents compressive strength tests, considered a baseline parameter critical for sustainable construction (ABS recycling) and the design of structural walls. Multicomponent Portland cement CEM II/C-M (V-LL) 32.5 R, with a density of 3.0 g/cm³, was used in the tests. The cement composition complies with the PN-EN 197-5:2021-07 standard (PN-EN 197-5:2021-07). Cubic samples measuring 10 cm × 10 cm × 10 cm were prepared. Figure 1 shows several autoclaved concrete samples incorporating ABS regranulate and basalt powder, highlighting fractures with visible additives after the autoclaving process. For testing, raw material batches were prepared according to the research plan outlined in Table 1, then foamed and molded into samples. All samples were produced at an aerated concrete manufacturing plant under semi-industrial conditions.

The research plan was developed using Statistica 10.0. Table 2 presents the experimental plan, formulated according to the mathematical design of experiments. A full factorial design 3**(2-0) was employed, with two independent variables, nine experimental runs, and one block.

The effectiveness of the modification was analyzed using Statistica 10.0 (Table 2). The share of basalt flour in the raw material subjected to autoclaving was 10 %, 20 %, and 30 %, while the share of ABS regranulate was 5 %, 10 %, and 15 %. Initial testing included compressive strength (Fig. 2), followed by density measurements (Fig. 3), given the high strength of ABS regranulate compared to autoclaved concrete.

Fig. 2.

Graph of the compressive strength of samples modified with ABS and basalt flour (own research)

Fig. 3.

Graph of the bulk density of samples modified with ABS and basalt flour (own research)

Favorable strength results, comparable to the reference sample (5 MPa), were obtained using a modification of 30 % basalt flour and 5 % ABS regranulate (BM30ABS5), which achieved a compressive strength of 4.9 MPa, and 10 % basalt flour with 5 % ABS regranulate (BM10ABS5), which reached 4.8 MPa (Fig. 4). Bulk density values ranged from 445 kg/m³ (BM20ABS15) to 490 kg/m³ (BM30ABS5).

Fig. 4.

Combined graph of compressive strength and bulk density of samples modified with ABS and basalt flour (own research)

The analysis of combining basalt flour with ABS regranulate revealed clear benefits of the proposed modification. The resulting material achieved strength levels within the 2 MPa – 6 MPa range typical for autoclaved concrete.

The proposed modification achieved compressive strength values of 4.45 MPa – 4.9 MPa and bulk densities of 445 kg/m³ – 490 kg/m³, corresponding to the typical strength classes for aerated concrete. At the same time, quartz sand usage was reduced in favor of ABS regranulate and basalt flour/powder (Fig. 5). Future investigations should explore the use of ABS regranulate as the sole aggregate in autoclaved materials and examine the microstructure at the SiO₂-ABS-binder interface, given the strength differences between the modified material and its constituent components.

The combination of basalt flour and ABS regranulate in avtoclaved concretes demonstrated significant improvements, achieving strength comparable to cellular concrete while reducing quartz sand use, highlighting its potential as a sustainable alternative to natural aggregates. Autoclaved aerated concrete modified with 5 % – 15 % ABS regranulate and 10 % – 30 % basalt powder achieved compressive strength in the range 4.45 MPa – 4.9 MPa and bulk density of 445 kg/m³ – 490 kg/m³. The optimal combination in terms of strength and density was obtained for BM30ABS5 / BM10ABS5.