Papers by Keyword: Recycled

Abstract: This study proposes an alternative formwork system using recycled plastic to reduce the use of wood in the construction of tie columns and tie beams in San Pedro Sula, Honduras. The main objective is to develop a more sustainable and efficient solution to reduce wood consumption and the high costs that these formworks represent in projects. A geometric design was developed using reinforced recycled plastic boards, tailored to meet the structural needs of secondary concrete elements. The study applied a comparative methodology, evaluating the proposed system against traditional wooden formwork based on parameters such as assembly time, reuse potential, resistance, and material reduction. Results showed a 20% to 30% decrease in formwork assembly and disassembly time, along with an over 80% reduction in wood consumption. The recycled plastic formwork demonstrated greater durability and resistance to moisture compared to wood, offering improved performance in terms of lifespan and reusability. In conclusion, the proposed system proved to be a functional, cost-effective, and environmentally friendly alternative for the construction sector in Honduras. It also promotes the reuse of plastic waste in the development of modern, sustainable construction technologies.

Abstract: Virgin high-density polyethylene (vHDPE), recycled (rHDPE), and mixed vHDPE/rHDPE matrices and wood plastic composites based on these mixtures + 50 wt.% of plywood sanding dust (PSD) and 3 wt.% coupling agent maleated polyethylene (MAPE) physical-mechanical properties (tensile, flexural strength and modulus, impact strength, and microhardness) were investigated. It was observed that all defined properties depend on the content of rHDPE in the pure polymer matrix and corresponding WPCs. Tensile strength and modulus decreased a bit, but flexural modulus actually had no changes. At the same time, a decrease in impact strength and a significant increase (up to 2 times) in microhardness are observed. From all the investigated matrices, the most perspective seems to be the matrix with a vHDPE/rHDPE ratio of 75/25, whose mechanical properties are acceptable for the preparation of the WPCs based on plywood sanding dust. The compatibilization possibilities tests of different mixed matrices done by the DSC method in the air showed that the mixed vHDPE/rHDPE compositions compatibility is sufficiently good at different proportions. For all mixed matrices, only one relatively symmetric band with one peak of melting was observed. Differential scanning calorimetry (DSC) tests in an inert environment showed that during the first heating cycle, HDPE components are only partially compatible (two peaks of melting temperatures are possible to fix). On the contrary, after the cooling and crystallization processes, during the second heating of the same sample, these two bands completely merge, and like in the air, only one maximum melting temperature peak was observed. The values of thermal oxidation temperature and melting temperature are the highest for virgin vHDPE but the lowest for rHDPE. The values of all corresponding parameters of mixed matrices reduce proportionally with an increase in rHDPE content in the mixtures.

Abstract: This experimental research aims at investigating the possibility of utilizing local glass waste in the production of concrete for construction. Experimental program is conducted to study the effects of using glass powder (GP) obtained by crushing of local glass waste as partial replacement of cement on the fresh and hardened properties of concrete. Five percentages of GP were used: 0%, 10%, 15%, 20%, and 25% by weight of cement. For all concrete mixes, slump test was made for fresh concrete and tests were made for hardened concrete to evaluate compressive strength, splitting tensile strength and flexural strength. The experimental results show that workability increased by increasing GP content. Concrete compressive strength was reduced for all mixes with glass powder, but is improved by time. The positive effect of using GP as cement replacement extends to 20% on concrete tensile strength. The results showed that as the amount of GP increases the flexure strength. The use of 20 % glass powder as cement replacement decreased concrete compressive strength by 3.2% at 56 days, achieved better tensile strength at 28 days, increase flexure strength by 18.6% at 28 days and showed good performance compared to all other mixes.

Abstract: In this paper, the selected properties of lightweight composites based on the different kinds of binder and recycled waste plastics aggregate were studied. Plastic waste e.g. foamed polystyrene, polypropylene, polyurethane foam or ethyl vinyl acetate (EVA) as an aggregate in these composites was used. Cement CEM II B/S 32.5 R and an organic-based adhesive with the business name Conipur 360 were used as a binder. The cement composites consisted of constant water to cement ratio 0.50 and dose of cement 175 kg/m³. Mixtures of adhesive composites were prepared with constant dose of adhesive 100 kg/m³. The kind of recycled waste aggregate was only changed. The physical properties, such as bulk density, compressive strength and thermo-technical properties were verified. The application of organic-based adhesive resulted in a significant decreasing values of the bulk density (100 kg/m³ - 230 kg/m³) and the thermal conductivity coefficient (0.0511 W/m.K - 0.0686 W/m.K) of lightweight composites. The negative impact of this type of binder resulted to a decreasing value of the compressive strength (0.15 MPa - 0.32 MPa). Use of cement binder caused to an increasing of bulk density (290 kg/m³ - 375 kg/m³) and worsening of the thermal conductivity coefficient of these composites (0.0660 W/m.K - 0.0799 W/m.K). The compressive strength values of cement composites ranged from 0.24 MPa to 0.50 MPa.

Abstract: Acrylonitrile-butadiene-styrene (ABS) is one of the most widely used plastic. The application of ABS increases rapidly in industries recently. The drawback of the increasing demand of ABS is the increment of ABS waste. Huge increment in ABS waste has led to the increasing of environmental pollution. The demand in green technology and sustainability of resources has urged the need of recycling of ABS waste. However, the mechanical properties of the recycled ABS are deteriorated. Hence, this work aims to study the mechanical properties of blend virgin and recycled ABS. The first sample started with 100wt% of virgin ABS. While the second to eleventh samples was a mixing of virgin and recycled ABS at 10wt% incremental recycled ABS. The last sample was prepared using 100wt% of recycled ABS. The results show that the tensile strength of 100wt% of recycled ABS is slightly decreased as compared to 100wt% virgin ABS. Similar trend was observed on traverse rupture strength (TRS) when the TRS for 100wt% of recycled ABS is lower by 8% when compared to 100wt% of virgin ABS. The most significant change is observed on the impact strength. The impact strength for 100wt% of recycled ABS is substantially dropped by 86% as compared to 100wt% of virgin ABS.

Abstract: Materials play a fundamental role in any branch of civil engineering. From ancient times to the present day, society has required enormous amounts of construction materials, which implies an excessive exploitation of materials that come directly from nature. This paper explains the main differences, similarities, benefits and characteristics of the 2 designs of asphalt mixtures by means Marshall methodology. The first design is for control mixture, which was elaborated with a conventional asphalt AC-20 and 100% of natural aggregate (NA). The second design is for asphalt mixture with 30% of recycled concrete aggregate (RCA) and 70% of NA. Finally, it was determined that both designs have similar characteristics, which indicates that the use of 30% RCA in asphalt mixtures is adequate. In addition, it represents economic and environmental savings.

Abstract: Rotational molding is the forming process that use in produce large product, complexity product and hollow product with the limitation of process ability and material. Most of the rotational molding is a large product with a longer useful life compare to other technique, so to reused the material from other process can help to increase the competition of rotational molding in the market. This paper chooses recycled HDPE from blowing process due to it generally used by the market and not difficult to find. So in this paper choose to studies the blend of virgin LLDPE (linear low density polyethylene) and recycled HDPE (high density polyethylene) for application in septic tank by rotational molding process. Various ratio of blending were investigated to find the morphology, mechanical properties and the relation of melt flow rate and rheology. Mechanical properties are generally referred to tensile test, hardness test, impact strength and Morphology by Scanning Electron Microscope. Many studies have carried out to investigate about rotational molding forming process control, mold and process condition, some on material ability and new material to used in rotational molding to improve the mechanical properties and various technique in forming by rotational molding. But this article will investigated more about the use of recycled material from other forming technique process (which refer to blowing process in this article) to use in rotational molding process for produce septic tank compare to the commercial quality.

Abstract: This research aims to investigate the effect on tensile strength of the recycled chip AA6061 aluminium alloy metal by using powder metallurgy method. Material used is recycled aluminium Chip AA6061 and Al powder. The recycled AA6061 chips mixed together with various compositions of Al powder content were fabricated to form a specimen by hot compaction technique. The compaction using hot pressed at 30 tons with holding time of 60 minutes. The final product was analyzed by tensile test shown the specimen A5 have higher ultimate tensile strength (UTS) 156.404 MPa and yield strength (YS) at 107.399 MPa. Scanning Electron Microscopy (SEM) was conducted to observe the microstructure of fracture surface existing on the tensile specimens.

Abstract: Effects of irradiated rPP compatibilizer, on the mechanical and thermal properties of recycled polypropylene/microcrystalline cellulose composites (rPP/MCC), are investigated. rPP is irradiated with an electron beam at dosages ranging from 10, 20, 30 to 50kGy. A matrix, containing of unirradiated and irradiated rPP (50:50 by ratio), is then added to 5, 20 and 40wt% MCC fibres. The composites are prepared using a twin screw extruder, followed by injection moulding. The properties are then characterized using tensile and thermal degradation tests. The improvement of Young’s modulus by up to about 45% suggests a compatibilising effect of the irradiated rPP. Fracture surface observations reveal an adhesion between rPP matrix and MCC fibres. However, the thermal stability deteriorated with the addition of MCC and irradiated rPP.

Abstract: The paper is aimed at storing heat with gravel. During testing, we used various kinds of recycled aggregates, were studied their characteristics and suitability for ground heat storage. The most important feature is the specific heat capacity which was measured through own construction of the calorimeter. The construction of the calorimeter and measured results are summarized in this paper.