Details

The construction industry seeks sustainable materials to improve energy efficiency and reduce environmental impact. This work aimed to examine thermal behavior of 3D printed concrete (3DPC) containing recycled PET flakes as partial replacement for aggregates. Three mixes with 0%, 5% and 10% PET by weight were designed considering water/binder ratio, flow, extrudability and buildability. Rice-husk ash, xanthan gum, micro-silica and superplasticizer were added to optimize the mix design. Thermal performance was analyzed employing thermographic images and hot plate/thermometer under freezing and heated conditions. Moreover, the durability property was evaluated by exposing the samples to water and chemical attack (5% dissolved sulphate salt solution) for three-month period and monitoring the weight change of the samples and ultimately, the compressive strength test of the cubes was also carried out. The test result showed thermal conductivity decrease from 2.02W/mK (0% PET) to 1.88W/mK (5% PET) and 1.87W/mK (10% PET) demonstrating improved insulation, moreover, compressive strength values were 18.3MPa (0% PET), 16.0MPa (5% PET) and 12.7MPa (10% PET). The 5% PET mix yield target 15-20MPa range, suitable for load-bearing applications requiring energy efficiency. The 10% PET with low strength makes it better for non-load bearing applications needing insulation. This study demonstrates 3DPC’s PET infused potential to address plastic waste challenge and reduce natural sand use in concrete production. Conclusively, the 5% PET mix offers the best balance between insulation, strength, and durability. Its result demonstrated that a modest amount of recycled plastic can enhance sustainability of 3D-printed concrete without significantly affecting its load-bearing performance. Higher PET content improves insulation but weakens the material strength and resistant to chemical attack. These findings point to a practical way of PET waste utilization as a partial sand replacement thereby enhancing sustainable construction material development and reduction of plastic bottles waste in the environment.