•The addition of PET fibre to UHPGC containing UPOFA and SF has the potential to improve its flexural and tensile characteristics significantly.•The combination of PET fibres with UPOFA and SF ...increased the flexural toughness and ductility of UHPGC considerably.•The PET fibre inclusion reduced the flexural stiffness of the UHPGC and enhanced its strain capacity.
Ultra-High performance Fiber Reinforced Green Concrete is an advanced technology in concrete sustainability via the utilization of green alternative materials, with superior mechanical properties. The effects of adding recycled waste plastic bottles in the form Polyethylene Terephthalate (PET) fiber on the flexural and tensile behavior of Ultra-High Performance PET Fibre Reinforced Green Concrete (UHPPFRGC) containing different volumes of Ultra-fine palm oil fuel ash (UPOFA) and Silica Fume (SF) have been investigated. Up to fourteen concrete mixtures were designed with varying UPOFA and SF content as partial replacement of ordinary Portland cement (OPC) in volumes of (25%- 50%) UPOFA and (10%-20%) SF. PET fibres were added at a portion of 1% from the total mixture volume. The results showed that the addition of PET fibres modulates the stiff and brittle behaviour of Ultra High-Performance Green Concrete (UHPGC). The optimum values were registered with (U25-SF20-UHPPFRGC) mix containing 25%UPOFA, 20%SF and 1% PET fibres. A considerable increased in ductility index was achieved, with superior compressive strength, splitting tensile strength, flexural strength, flexural toughness and flexural stiffness of 153 MPa, 9.31 MPa, 30.1 MPa, 29.7 kN.mm and 18.225kN/mm, respectively. Thus, the utilization of ternary blended binders (OPC-UPOFA-SF) with recycled PET fibres could promote the production of UHPPFRGC possessing adequate flexural and tensile strength properties.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•An investigation on production of agro-waste cement composite from nutshells waste was introduced.•Different nutshell contents (0.5, 1, 1.5, 2, and 2.5% by weight of cement) were adopted in ...production of the this type of composites.•Hardened and mechanical properties of this new agro-waste composite were evaluated.•The addition of nutshells significantly enhances the compressive strength.•Other properties of the cement composites, such as the thermal insulation were also improved by the inclusion of nutshells.
Different countries have been encountering significant obstacles in the disposal of agro-wastes in landfills, with a recent increase in landfill sites receiving inadequate or no treatment. Moreover, in addition to high disposal costs, several factors related to landfills pose a significant threat to human health and ecosystems – examples include leachates, toxins, and greenhouse gases, which constitute environmental problems. Nutshells are an example of agro-waste materials that can be utilized in different industrial and engineering applications to help save the environment. This study aims to evaluate and investigate the utilization of nutshells (from pistachios, walnuts, and hazelnuts) as a replacement material to produce an agro-waste cement composite. Different nutshell contents (0.5, 1, 1.5, 2, and 2.5% by weight of cement) were used in the preparation of the cement composite mixtures. The nutshells were characterized by X-ray diffraction and energy-dispersive X-ray spectroscopy, and scanning electron microscopy (SEM) was also implemented to observe the prepared cement mortar composites. The compressive strength, hardness, thermal conductivity, and water absorption of cementitious composites were investigated, highlighting that the addition of nutshells significantly enhances the compressive strength. Agro-waste cement composite specimens with a nutshell content of 2.5% exhibited the highest compressive strength. Other properties of the cement composites, such as the thermal insulation properties, were also enhanced by the inclusion of nutshells. For instance, thermal conductivity of all mortar composite samples reduced by 57, 48, and 45% for the addition of 2.5% walnut, pistachio, and hazelnut shells, respectively. This eco-friendly material represents a potential way to address the generation of waste products from agricultural activities and nature; suggested uses of such composites include their application in lightweight panels, thermal insulators, and sustainable building blocks, among several other materials.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In recent years, plastic wastes represents one of the main threats to the environment. However, the use plastic fibers in concrete could be a sustainable solution to the problem of plastic waste ...accumulation. Moreover, the use of fibers in the production of concrete is one attempt to remedy this brittleness and to enhance other properties such as toughness and ductility. In this study, polyethylene terephthalate (PET) fibers produced from waste plastic bottles was used in reinforced concrete RC beams. PET fibers were included in concrete at two percentages (0.5% and 1% by volume). The influence of layered distributions of PET fibers in concrete on the flexural behavior of beams was also evaluated. For each mix, three layered PET fibers RC beams were prepared. Comparison with beam containing the same PET fiber percentage (full section) was presented as well. The flexural test parameters included the determination of first cracking, the yield, and the ultimate load, in addition to the deflections related to these loads. Furthermore, failure modes, toughness, and ductility were also evaluated. The use of PET fiber concrete with a layered distribution enhanced the ultimate load considerably. Moreover, the load–deflection relationships illustrated a tendency of layered PET fibers concrete beams to exhibit further deflections before failure. The toughness capacity approximately doubled for beams reinforced with 1% PET fibers concrete in the bottom quarter, bottom half, and top half sections of layered RC beams. This impressive enhancement of the flexural toughness and ductility using the layered distribution is a promising finding that could promote this type of sustainable concrete in various structural applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The utilization of minimum natural materials content in the production of concrete represents the main concern of many researchers. In addition, lightweight aggregate concrete is desired for its low ...weight and modified physical properties. This study aims to produce lightweight aggregate concrete with adequate strength utilizing crushed clay brick (CCB) aggregates from discarded or broken brick pieces. The CCB aggregates are utilized by replacement of natural aggregate at (10%, 20% and 30%). Three types of CCB aggregate concrete series are produced. In the first series, natural sand is replaced with similar size CCB aggregate (red and yellow). The second series is produced by the complete replacement of coarse aggregate with yellow, red and an equal two portions of yellow and red coarse CCB aggregate. The third series with 100% coarse CCB aggregate is produced by further replacement of fine aggregate up to 30% CCB aggregate. In all mixes, the CCB aggregate is used in its dry state (without pre-wetting). The workability of produced mixes are investigated. Investigations on density, water absorption and compressive strength is also presented. Results indicate the possible production of lightweight CCB aggregate concrete suitable for structural applications. Superplasticizer (SP) significantly affect the workability of crushed brick aggregate. A blend of yellow and red CCB aggregate is also suggested to produce workable lightweight concrete suitable for structural applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Green concrete composite produced from Polyethylene terephthalate (PET) fibers may be considered an important issue in sustainable construction. Therefore, the behavior of self-compacting concrete ...(SCC) slabs containing PET fibers under impact loads was investigated. PET fibers from waste plastic were added to SCC with an aspect ratio of 28. One reference concrete mix, from which all other mixes were developed, was used to produce eight SCC mixers containing different volumetric ratios of plastic fibers percentages (0.25%, 0.5%, 0.75%, 1%, 1.25%, 1.5%, 1.75%, and 2%). Experiments showed that the inclusion of PET fibers in SCC results in an increase in compressive and flexural strengths. The behavior of SCC slabs under impact loading was studied. A significant improvement was found in the resistance to impact load and energy absorption capacity of slabs containing PET fibers. The increment in the time of max deflection for the concrete mixes containing PET fibers increased significantly, thereby indicating the enhanced capacity of SCC to absorb further energy under low velocity impact. This improvement in the behavior of SCC under impact by the inclusion of PET fibers may lead to further applications of this type of concrete in sustainable structures.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
AbstractOne of the main aspects of sustainable engineering constructions is the recycling of byproduct materials or wastes, including those from different agricultural crops. The influence of ...ternary-blended binders—ordinary portland cement (OPC), ultrafine palm oil fuel ash (UPOFA), and silica fume (SF)—on the engineering and transport properties of ultrahigh-strength green concrete (UHSGC) has been investigated. Up to 50% of the UPOFA was combined with varying proportions of silica fume at 5%, 10%, 15%, and 20% from the volume of the portland cement in order to quantify their influence on the engineering and transport properties of the UHSGC. The results showed that the UPOFA inclusion reduced the early age strength of the UHSGC at 3 and 7 days, then slightly improved the strength at the ages of 28 and 90 days. Whereas, the SF inclusion, as a ternary-blended binder in combination with the UPOFA, significantly enhanced the early and long-term strength for all UHSGC mixes, in comparison with the OPC control mix. The highest compressive strength was realized at 20% SF content, which exceeds 152 and 157 MPa at the ages of 28 and 90 days, respectively. The transport properties of the UHSGC, specifically, porosity, water permeability, and rapid chloride permeability, were significantly improved with the utilization of the ternary-blended binder. Consequently, the overall results demonstrated the feasibility of utilizing up to 70% of byproduct based pozzolanic materials (UPOFA and SF) as a blended binder to partially substitute the portland cement to improve the properties and durability performance of the UHSGC. Furthermore, new relationships between compressive strength and transport properties of the different mixes were presented, and a good correlation between these properties and compressive strength for this type of concrete was obtained.
•The production of green sustainable concrete utilising ultrafine palm oil fuel ash (UPOFA) and waste plastic Polyethylene Terephthalate (PET) fibres was presented in this study.•The proportions of ...UPOFA were (20% and 40%) as a partial replacement of the total cement binder combined with 1% PET fibres.•The combination of UPOFA and PET fibres enhanced strength and transport properties of Ultra-High-Performance PET Green Concrete (UHPPGC).
The production of green sustainable concrete with enhanced performance against severe environmental conditions by using recycle waste materials has been a primary concern for recent studies. This article reports a study on investigating the effect of incorporating ultra-fine palm oil fuel ash (UPOFA) with shredded recycled waste bottle in form of Polyethylene Terephthalate (PET) on the engineering and transport properties of ultra-high-performance concrete. UPOFA was used as a partial replacement binder in varied proportions (20% and 40%) of the total cement binder, whereas shredded recycled PET bottles were added as reinforced fibre by 1% of the total mix volume. The greatest compressive strength was registered by a combination of 20% UPOFA and PET fibre in U20-UHPPGC. The combination of 40% UPOFA and PET fibres in U40-UHPPGC mix demonstrated a superior enhancement in terms of transport properties at the age of 28 days, such as porosity, initial surface absorption, gas permeability, water permeability and rapid chloride permeability. Thus, pozzolanic UPOFA can improve the engineering and transport properties of ultra-high-strength concrete. The overall results indicated that the PET fibre reinforced with UPOFA can produce UHPPGC with promising improvements in engineering and transport properties. The incorporation of waste materials into concrete constructions can reduce cement consumption and prevent the environmental pollution with save energy at the same time.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Rubber aggregate recycled from waste tires are added to self-compacting concrete to improve some of its properties, such as durability, toughness, and concrete resistance to impact and vibrations. In ...this study, modified hybrid rubberized self-compacting concrete (SCC) was produced by utilization of recycled tire rubber aggregate, plastic waste (PET), and steel fibers. Rubber was used as a partial substitute for sand, with only 10%, while the fibers were utilized in two different proportions of 0.25% and 0.35% (volume). Several tests were achieved to evaluate the rheological properties of the modified hybrid fiber rubberized SCC such as slump flow, T500, V-funnel, L-box, and segregation resistance. In addition, the hardened properties such as density, compressive, tensile strengths, and modulus of elasticity were evaluated. Microstructural evaluation of rubberized mixes was conducted. The results showed that the addition of rubber aggregate at 10% content reduces the rheological properties of SCC. The T500 mm was influenced significantly up to 15% increase. Moreover, compressive strength decreased by about 14% at same amount of rubber aggregate, while the addition of hybrid fibers improves the mechanical properties despite the negative effect on the rheological properties of rubberized SCC. The tensile strengths increased significantly by the inclusion of 0.35% hybrid fibers. The positive action of the two types of fibers led to this increase. The combination of rubber aggregate and the hybrid fibers in SCC could affect its mechanical properties positively by balancing the weakness in strength due to the lack in of bonding between rubber aggregate and cement paste and to avoid the severe deterioration in tensile strength, improve the ductility, and enhance the energy absorption capacity, especially for members subjected to earthquake effects.
•Crumb tire rubber aggregate, plastic waste (PET), and hooked ended steel fibers was utilized in this study.•Several tests were achieved to evaluate the rheological properties..•The hybrid fibers improve the internal cohesion and interaction of rubberized SCC.•The low content of rubber aggregate (10%) maintained an acceptable reduction in strengths.•There was a balance between the reduction in fresh properties and the desired strength.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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