Flexural Strength

Öz: Lifli betonlar; sahip oldukları yüksek eğilme dayanımı ve içeriğinde kullanılan liflerin yüksek çekme dayanımı sayesinde çeşitli endüstriyel uygulamalarda, fabrika zeminlerinde, benzin istasyonlarında, prefabrik beton uygulamalarında yaygın olarak tercih edilmektedir. Bu çalışmada, aynı işlenebilirliğe sahip olan rastgele yönlenmiş cam ve çelik lifli betonlar ile tabakalı çelik tel ve cam elyaf ağları içeren beton kompozitlerin eğilme dayanımları incelenmiştir. Hacimce %0.5, %1 ve %1.5 oranlarında lif kullanılarak rastgele yönlenmiş cam ve çelik lifli beton grupları oluşturulmuştur. Çelik tel veya cam elyaf ağları içeren tabakalı beton kompozitler, rastgele yönlenmiş cam veya çelik lifli betonların lif hacmine eşdeğer olması için 3, 5 ve 7 tabakalı olarak üretilmiştir. Sonuçlar incelendiğinde; tabakalı lifli beton kompozitlerin eğilme dayanımlarının, aynı işlenebilirliğe sahip rastgele yönlenmiş lifli betonların eğilme dayanımlarından lif türü fark etmeksizin daha yüksek olduğu belirlenmiş olup tabakalı lifli beton kompozitlerin üretiminde yüksek eğilme dayanımı ve uygun işlenebilirlik için herhangi bir kimyasal katkı kullanımının gerekmediği tespit edilmiştir. Ayrıca tabakalı çelik telli beton kompozitlerin eğilme dayanımlarının, tabakalı cam elyaflı beton kompozitlerin eğilme dayanımlarından daha yüksek olduğu ve tabaka sayısının çelik telli beton kompozitlerde eğilme dayanımı sonuçlarını daha fazla etkilediği belirlenmiştir.

Recycled concrete aggregate has been widely researched to be capable of replacing natural coarse aggregate in concrete, however, with some inadequacies in its concrete’s ability to attain the same feat in mechanical properties as normal concrete. This research work attempts to improve the strength characteristics of concrete containing recycled coarse aggregate with the addition of admixtures (Micro-Silica and Superplasticizer) and Polypropylene fibre. Results showed that admixtures significantly improved the workability and mechanical properties of CRCA at all RCA replacement levels. Addition of PPF had significant effect on the flexural and splitting tensile strengths of CRCA, but not much impact on the compressive strength.

Reinforcement of the damage-prone areas of wood pallet stringers with metal connector plates (MCPs) may increase useful pallet life or permit use of less desirable wood species. This will improve the utilization of our timber resources and landfill space. Whole pallets and individual stringers, reinforced at the inner notches, were tested in static bending. Stringer end segments, reinforced on the sides, were tested for resistance to fork tine impact. Reinforced stringers had greater strength, and in some cases greater stiffness, than unreinforced stringers. Reinforced end feet withstood a greater number of tine impacts to failure than did unreinforced end feet. Wood species had a greater influence on MCP reinforcement performance than did stringer width for all components. In general, tests of whole pallets, after accelerated handling, supported the results from component tests. This suggests that component testing may be a practical means of assessing the effect of reinforcement on pallet performance. Over 560 million wood pallets were manufactured in the United States in 1992 (8), making pallets second only to the housing industry in lumber consumption (13). Properly designed pallets will withstand many load cycles, but over time, damage may occur. As society becomes more concerned with waste, and restrictions on landfill space increase, disposal of these damaged pallets will become more difficult and costly. Methods of repairing damaged pallets with metal connector plates (MCPs or plates) were investigated and reported in another article (5). MCPs applied to damage-prone areas of the pallet during manufacture, however, may also prevent or delay the initial damage. This reinforcement has the potential to extend the service life of wood pallets or improve service performance. Reinforcement may also allow the substitution of stringers made from underutilized, weaker species for more traditional, but costlier, woods. Although many parts of a pallet maybe damaged, this research examined only notched stringers in stringer-class pallets. Deckboards are damaged more frequently, but replaced more easily than stringers (10). Currently, MCPs are not used for deckboard reinforcement. With notched pallet stringers, the most common damage is cracking at the interior notches. Typically, two notches are cut in stringers to satisfy a common requirement for forklift tine entry from any side of the pallet. These notches create stress risers, causing a notched-stringer pallet to have much less strength than an equivalent pallet with unnotched stringers. Pallets are commonly used in a racked-across-stringer (RAS) storage mode, where the stringers can fail at the

The flexural modulus of elasticity (MOE), flexural modulus ofrupture (MOR), and density of used pallet parts were measured and compared to the same properties of new parts. Seventy-four percent of used pallet parts sampled were hardwoods, and 26 percent were softwoods. The average mixed hardwood parts were 41 percent stronger and 40 percent stiffer than the mixed softwood parts. The mixed eastern oaks were the most common species sampled, and reflected the relative volume of these species used to make new pallets. The average dry used oak deckboards were 47 percent stronger and 23 percent stiffer than green new oak parts, due primarily to the difference in moisture content (MC). However, when adjusted to the same MC, the predicted average MOR and MOE of used oak deckboards was 15 and 21 percent less, respectively, than new oak deckboards. Without sortation, used parts dimensions were more variable than that of new parts. Material property values for various groupings of used parts were developed for use in future versions of the Pallet Design System program dealing with repaired and rebuilt pallets.

The use of plastics in daily life continues to increase in a variety of uses. One of the most commonly used plastic that is difficult to decompose is Polyethylene Terephthalate (PET) plastic. In recent years, such as the construction industry, has been trying to reuse the waste as construction material. Therefore, this research aims to contribute by exploring the effect of PET plastic fiber substitution as fine aggregate on the flexural strength of concrete. PET plastic fibers were used at 0.8% as partial replacement of fine aggregates and then chopped to a size of 5 cm long, 1-3 mm wide. The test results indicate that concrete containing 0.8% PET plastic fiber as a substitution of fine aggregate has a higher flexural strength value of 4.32% which is better than normal concrete. Therefore, using recycled PET fiber in concrete is needed as an eco-friendly and sustainable construction material in the future in order to minimize PET plastic waste and replace it as a concrete constituent material.

In this study, zirconium oxide nanofiber with a mean diameter of 100 nm was added to concrete at various concentrations as a cement replacement. Various tests, including compressive strength, splitting tensile strength, flexural strength, and electrical resistance tests, as well as a rapid chloride penetration test, were performed on specimens containing zirconium oxide nanofibers for the concrete assessment, and the results were compared to those obtained from control specimens that did not contain nanofibers. The results showed that adding zirconium oxide nanofibers at 135 gr/m 3 of concrete yielded a 28-day compressive strength equal to 44.62 MPa, which exhibits a 20.40% increase in strength with respect to the specimen that lacked nanofibers. The flexural strength and splitting tensile strength tests at 28 days of age and in the presence of 135 gr/m 3 mentioned nanofibers were increased by 22.28 and 33.47%, respectively, in comparison to the control specimens. Moreover, revealed that at 28 days of age, in the specimens containing 270 gr/m 3 zirconium oxide nanofibers, the migration coefficient of chloride ion was reduced by 29.86%, and its electrical resistance was increased by 68.33%. These findings highlight the potential of nanofibers as a promising solution for enhancing the strength and performance of concrete structures.

Photovoltaic (PV) modules are generally installed by the application of empirical rules aimed at reducing shadows during the periods of high solar irradiation. A traditional installation on a horizontal surface results in largely spaced rows of modules with a relatively low tilt angle. The addition of inter-row reflectors results in more direct and diffuse flux transmitted to the cells. The "Aleph" (Amélioration de l'Efficacité Photovoltaïque) project aims to define clear rules for optimal settings of systems of PV module rows with fixed inter-row planar reflectors in a given location and under a given climate. Two PV technologies are tested for performance with this type of system: amorphous silicon (a-Si) and polycrystalline silicon (p-Si). This work combines experiments on panel behavior in an outdoor environment on the SIRTA (Site Instrumental de Recherche par Télédétection Atmosphérique) meteorology platform and a multiphysics numerical model used to couple all the important physical phenomena and accurately describe the system behavior. The model includes a ray tracing radiation/optics module based on the Monte-Carlo method, as well as an electrical module simulated in SPICE. This work presents the influence of the string mismatch losses, present at periods of heterogeneous illumination, on the yield of PV modules augmented by static planar reflectors.

This research work is devoted to the experimental investigation of both rheological and mechanical properties of self-compacting concrete (SCC) produced with waste galvanized copper wire fiber and rice husk ash (RHA). In the study, three different volume fractions of 0.5 p to 0.75 percent, 1 percent of scrap copper wire fiber as reinforcing material, and 2 percent RHA as cement replacement were used. To evaluate the fresh characteristics of SCC, the slump flow, J-ring, and V-funnel experiments were conducted for this investigation. Compressive strength, splitting tensile strength, and flexural strength of the concrete were conducted to assess the hardened properties. The test was carried out to compare each characteristic of plain SCC with this modified SCC mixture, containing RHA as pozzolanic materials and copper fiber as reinforcing material. Incorporating copper fiber in the SCC leads to a drop in fresh properties compared to plain SCC but remains within an acceptable range. On ...

Polymethyl methacrylate (PMMA) has garnered significant attention in the field of dentistry due to its wide applications. This paper proposes the incorporation of the nystatin coated copper oxide (CuO) particles having desirable conductivity and antifungal properties, as a filler in the PMMA denture to address their low thermal conductivity, low impact strength, low fatigue resistance, and microbial adhesion. The prepared nystatin coated CuO particles were characterized with several analytical techniques. The nystatin coated CuO particles were mixed in different ratios (0%, 1%, 2%, and 4%) in PMMA corresponding to groups C, E1, E2, and E3, respectively. The prepared samples of composite PMMA with nystatin coated CuO were evaluated to determine their transverse strength, impact strength, Vickers hardness (HV), and thermal conductivity. Furthermore, antifungal properties of CuO particles, nystatin coated CuO particles, and their acrylic composites were evaluated against Candida albicans. Scanning electron microscopy (SEM) analysis confirmed the particles' spherical and irregular shapes. The particle sizes range from nano to micron level. Fouriertransform infrared spectroscopy (FTIR) and energy dispersive X-ray spectroscopy (EDX) analysis confirmed the coating of nystatin on CuO. X-ray diffraction (XRD) analysis showed the diffraction patterns and planes of CuO monoclinic shape structure. The composite prepared to have higher values of HV (19.53 AE 0.65, 20.16 AE 0.37, and 21.11 AE 0.75, respectively) as compared to the control. The impact strength values were measured high at 14.12 AE 5.55 kJ/m 2 for 2% containing nystatin coated CuO acrylic resins compared to control and other groups. The conductivity increased linearly with the addition of CuO particles. The addition of CuO particles causes a reduction in flexural strength as compared to the control group. As the concentration of nystatin coated CuO (1%, 2%, and 4%) in acrylic samples increased, the antifungal properties were improved. Thus, the incorporation of optimized concentrations of nystatin coated CuO particles in acrylic resin resulted in the improved mechanical, thermal, and antifungal properties.

The objective of this study was to determine the effects of TiO 2 , Ag-TiO 2, and Cu-TiO 2 nanoparticles (NPs) addition on the mechanical and antibacterial properties of resin-based sealants. TiO 2 , Ag-TiO 2, and Cu-TiO 2 NPs were characterized with FTIR, Raman, SEM-EDX, TEM, XPS, and XRD, and evaluated for cytotoxicity study. After characterization, the nanoparticles were mixed with commercial pit and fissure sealants (PAFS) in ratios of 1 and 2%. A total of 7 groups were made, control group (PAFS only) and experimental groups (1%-2% TiO 2 , 1%-2% Ag-TiO 2, and 1%-2% Cu-TiO 2 ). ISO standards were adopted to prepare samples for mechanical properties, i.e., compressive strength (CS), flexural strength (FS), and Vickers hardness evaluation. Samples were tested against Streptococcus mutans through an agar well diffusion test. The CS, FS, and Vickers hardness were increased for the Cu-TiO 2 group with respect to Ag-TiO 2 but values were less compared to TiO 2 groups. The highest flow rate was measured in the control group which was 8.16±0.06 mm and 9.17±0.1 mm after 3 and 10 mins respectively. In the agar well diffusion test, the control group showed no zone of inhibition, and the lowest zone of bacterial inhibition was found in PAFS with 1% TiO 2 NPs group (13.3 ± 1.5 mm) while the highest was found in PAFS with 2% Ag-TiO 2 NPs (21.8 ± 1.7 mm). Cudoped TiO 2 NPs showed more biocompatibility as compared to Ag-doped TiO 2 . The outcomes were statistically significant for all the mechanical tests and agar well diffusion antibacterial test as the pvalue ≤0.05 while for the cytotoxicity test, the p-value >0.05. The TiO 2 addition generally improved both the mechanical and antibacterial properties of pit and fissure sealant.

This research is aimed to study the possibility of recycled the PET wastes by forming the PET wastes as plastic semi-bars and used it as tension bars in simply supported reinforced concrete beams . Twelve beams specimens with dimension of (150*200*1400) mm are casted and tested to monitoring the effecting of these wastes as tension bars on the strengths and serviceability of reinforced concrete beams. The mechanical properties (compressive, splitting tensile and flexural strength) are evaluated in which specimens tested in age of 28 days. The tests results showed that all presented plastic semi-bars are failed except one case in which the deformed steel bar are used with additional layer of PET bottle cut into two parts which showed an increment in ultimate failure load and deflection of  3.03 % and 213.83 % respectively, larger than the reference beam specimens. Negatively effect of PET semi-bar on ultimate load of beams is due to bonding failure between PET bars and surrounding co...

The starting alumina powders were synthesized by chemical method under varied pH conditions - pH 6.5 and pH 8.5. The resulting powders were characterized by fine particle sizes, high surface area and crystalline structure. Powders at pH 8.5 were noted to have finer particle size than at pH 6.5. Due to their fine characteristic, the powders agglomerated during preparation of compacts. The alumina compacts were fabricated by (1) cold isostatic press (CIP) and sintered at 1550oC and 1650oC and (2) hot isostatic press (HIP) and also sintered at 1550oC and 1650oC. The CIP compacts showed large grains of alumina, whereas the HIP compacts were relatively fine-grained. The microstructure of both compacts exhibited abnormal grain growth more particularly in the CIP compacts. The synthesized powders were contaminated with Ca which accounted for the abnormal grain growth in both alumina compacts. The Ca present in HIP fabricated alumina compacts at pH 8.5 and sintered at 1650oC, gave high flex...

In some construction industries, there are difficulties in achieving the required concrete compaction, Self-compaction is an alternative option. Working with self-compaction self-curing concrete requires a unique approach. This study aims to examine the possibility of producing selfcompacting concrete with normal and high self-cure rates. This research observed how both the selfcuring and self-compacting concrete behaved under normal and high-strength conditions. Two stages were prepared for this investigation. The first stage of this research studied the effect of a curing agent on the fundamental characteristics of both normal-strength and high-strength self-compacting concrete, with the aim of achieving self-curing self-compacting concrete. The primary variables of this study include the grade of concrete, the type of curing agent, the reinforcing bars, and the dosage of these variables. In the second stage, reinforced concrete beams were cast with one of the two proposed concrete types, and their behavior was studied. The findings were analyzed in terms of the beginning cracking loads, the ultimate loads, and the crack patterns of the testing beams. According to the results, both the normal-strength and the high-strength varieties of self-curing self-compacting concrete are effective in providing structural features, which are absent from the processes of curing and compacting. Curing chemicals are utilized to mitigate the process of water evaporation in self-compacting concrete, hence enhancing the water retention capabilities of self-compacting concretes that possess enough hardened concrete characteristics.

In recent years, there has been a growing interest in the use of supplementary cementing materials and polymers to produce high-performance concrete. Utilizing a mineral substance as cement replacement in concrete has less environmental pollution and greatly increases the service life of the concrete structures due to improve the most of concrete properties in compared with conventional concrete. The aim of this project is an experimental study of high-performance concrete using metakaolin (MK) additive as partial replacement of cement and addition of the Styrene-Butadiene rubber (SBR) and Polyvinyl acetate (PVA), to conduct a novel research to investigate the effectiveness of the additives materials on the performance of concrete. It also investigates the effect of additional recycled plastic and glass fibre as reinforcements used in the modified concrete. Firstly, trial mixes of 460 cubes, 24 cylinders and 30 prisms were made to study the setting time, workability, mechanical prop...

In recent years, more attention is being paid to alternative disposal of wastes to lessen the harmful impact of these wastes to the environment. In the construction industry, alternative disposal of waste comes in the form of utilization of waste as a substitute construction material. Plastic, typically in the form of plastic bags and bottles, is one of the most abundant wastes in Manila, and, also among the most problematic when it comes to disposal due to its non-biodegradable nature. Hence, more attention is given to alternative use of plastics as a substitute material in construction. In this study, experimental investigation was conducted to assess the performance of concrete beams with shredded plastics, sourced out locally, as a supplementary material. Strength properties of a concrete beam, in terms of compression, tension, and flexure, were investigated for both plain concrete and concrete with shredded plastics. Results showed that concrete with shredded plastics were slightly higher than that of plain concrete in terms of tension and compression strength. Flexural strength of concrete with shredded plastic, also showed higher strength than that of plain concrete. Additionally, this study showed the applicability of elastic flexural theory to concrete beams with plastics.

This study explores the utilization of granite stone dust, a quarry byproduct, as a reinforcement material in polymer matrix composites (PMCs) for structural applications. The influence of stone dust particles on the thermal, wear, mechanical, and physical properties of reinforced polymer matrix composites (PMCs) was evaluated. Epoxy resin served as the polymer matrix, while granite stone dust was hybridized with palm kernel shell ash at five weight fractions (2 wt.%, 4 wt.%, 6 wt.%, 8 wt.%, and 10 wt.%). Both granite dust and palm kernel shells were processed to a uniform particle size of 106 μm to ensure consistency in the fabrication of the composite. Test specimens were developed via hand lay-up techniques. The samples were subjected to mechanical, physical, and wear tests in accordance with standards (hardness test, wear test, flexural test, impact test, thermal test, tensile test, and density test). The stone dust + palm kernel shell ash had superior performance against the control. Results further showed that the five weight fractions compare better than the control across all the properties tested, indicating the effectiveness of the stone dust as a reinforced material for structural applications. These findings establish granite stone dust as a viable, eco-friendly reinforcement and hybrid synergy. Its adoption can reduce quarry waste, lower material costs, and improve the performance of components such as flooring panels, decking, and other wear-critical structural elements, thereby promoting sustainable engineering practices in automotive, construction, and infrastructure development.

Hydrogen-containing silicone oil (HCSO) is widely used as a waterproofing agent in building materials, yet its tendency to agglomerate leads to uneven distribution and poor performance. In this study, we developed a controllable emulsification strategyusing Span 80, Tween 80, and OP-10 at a mass ratio of 8:1.6:6.4 (HLB = 9.05)-to produce a stable emulsified HCSO (EHCSO) with a stability value of 1. By incorporating 0.8 wt% EHCSO into gypsum-based self-leveling mortars (GSLMs), we achieved an optimal balance of properties: apparent density of 1.26 × 10 3 kg/m 3 , softening coefficient of 0.85, flexural strength of 6.81 MPa, compressive strength of 20.90 MPa, and contact angle of 126.39°. X-ray diffraction and SEM analyses confirmed that EHCSO does not alter the hydration phases but promotes the in situ formation of short columnar dihydrate crystals that fill pore spaces, refining the microstructure and enhancing mechanical integrity. This work contributes to the field by (1) introducing a scalable surfactant formulation for uniform HCSO dispersion in gypsum systems; (2) quantifying the link between surfactant HLB, emulsion stability, and waterproofing performance; and (3) demonstrating a dual improvement in both durability and strength, with potential applicability to a broad range of cementitious materials.

Objectives. To measure the flexural strengths and moduli of endodontic post materials and to assess the effect on the calculated flexural properties of varying the diameter/length (D/L) ratio of three-point bend test samples. Methods. Three-point bend testing of samples of 2 mm diameter metal and fiber-reinforced composite (FRC) rods was carried out and the mechanical properties calculated at support widths of 16 mm, 32 mm and 64 mm. Weibull analysis was performed on the strength data. Results. The flexural strengths of all the FRC post materials exceeded the yield strengths of the gold and stainless steel samples; the flexural strengths of two FRC materials were comparable with the yield strength of titanium. Stainless steel recorded the highest flexural modulus while the titanium and the two carbon fiber materials exhibited similar values just exceeding that of gold. The remaining glass fiber materials were of lower modulus within the range of 41-57 GPa. Weibull modulus values for the FRC materials ranged from 16.77 to 30.09. Decreasing the L/D ratio produced a marked decrease in flexural modulus for all materials. Significance. The flexural strengths of FRC endodontic post materials as new generally exceed the yield strengths of metals from which endodontic posts are made. The high Weibull modulus values suggest good clinical reliability of FRC posts. The flexural modulus values of the tested posts were from 2-6 times (FRC) to 4-10 times (metal) that of dentin. Valid measurement of flexural properties of endodontic post materials requires that test samples have appropriate L/D ratios.

Contained in this paper are the results of two separate studies, namely, 1) partially stiffened compressive elements of both edge and single intermediate stiffened flanges and 2) deflection determination of multi-web deck profiles. Both of these studies were based on the Canadian cold formed steel design standard (CAN/CSA-S 136-M89), with the results also applicable to the AISI specification. In the case of partially stiffened compressive elements, discontinuities in effective width estimates for sections with similar flanges and stiffeners were observed, resulting from a sudden change in the behavioural states. Recommendations are presented to rectify this discontinuity and at the same time simplifying the analysis procedure. Regarding the second study, the some-what lengthy alternative approach in S136 for determining the effective wiC:!th of multi-web profiles for deflection determination has been investigated. Recommendations are presented for a new approach which is consistent with the general unified effective width concept, i.e. the basic effective width expression is used with a variable plate buckling coefficient. With cold formed steel sections, longitudinal edge and single intermediate stiffeners are frequently used to stiffen compressive elements (flanges). The rigidity provided by a stiffener may not be adequate to fully stiffen the flange, hence, creating a partially stiffened element. The Canadian Cold Formed Steel Design Standard, CAN/CSA-S136-M89 [1] (S136), has recently been revised in order to allow for the design of partially stiffened compressive elements. Previously, compressive elements were treated either as stiffened or unstiffened elements if they were not fully stiffened. A compressive flange is considered stiffened if it is supported on one edge by a web and on the other edge by a web or an adequate stiffener. Another method of obtaining a fully stiffened

The paper presents a novel view on the scattering of a flexural wave in a Kirchhoff plate by a semi‐infinite discrete system. Blocking and channelling of flexural waves are of special interest. A quasi‐periodic two‐source Green's function is used in the analysis of the waveguide modes. An additional ‘effective waveguide’ approximation has been constructed. Comparisons are presented for these two methods in addition to an analytical solution for a finite truncated system. Copyright © 2016 John Wiley & Sons, Ltd.

Alternative cement technologies are gaining popularity as a result of the cement industry's increasing concerns
about the environment. Current research suggests improved environmental and durability performance cannot be
achieved without new binders. geopolymer concrete (GPC) uses fly ash (FA) instead of conventional Portland cement.
The purpose of this study is to examine the influence of FA: Ground granulated blast-furnace slag (GGBS) by employing
FA based-GPC compared to cement concrete on the compressive strength, splitting strength, modulus of rapture, density,
and water absorption of concrete. The varied ratio of FA 30%, metakaolin 70%, FA 30% and GGBS 70% for GPC was
utilized in this investigation. The outcomes obtained show that the GPC made of FA 30% and GGBS 70% gives higher
compressive strength than that of cement concrete at 7, and 28 days. The porosity and water absorption of GPC were
lower than that of cement concrete and the percentage of decrease was 1% for geopolymer containing GGBS as a binder.
These results can be modified further when using other materials with treated GGBS, FA, and MK, in different ratios.

It is with great pleasure that we unveil the twelfth (12 th ) volume and issue number one (1) of ESTEEM Academic Journal (EAJ)an online peer-refereed academic journal which publishes scientific and professional research articles and reviews in the fields of engineering, science and technology. We have included five (5) articles in this issue, four (4) of which were contributed by authors from UiTM Cawangan Pulau Pinang and one (1) from USM. The articles cover a wide range of topics in the fields of civil engineering, applied sciences, computer and math science, as well as pharmacy, all of them being interesting and innovative. We are enthusiastic about the articles published in this issue and hope you would enjoy reading it as much as we did. EAJ would not exist without the continued support of the top management of UiTM Cawangan Pulau Pinang. Therefore, we would like to grab this opportunity to extend our sincere appreciation and utmost gratitude to Assoc.

In this study, we performed a multi-scale three-dimensional (3D) analysis of a new type of lightweight composite material made with coal fly ash and expanded polystyrene wastes. For this, a methodology for identifying and quantifying the microstructure property of the lightweight composite material was developed using X-ray micro-tomography. The material studied mainly contained polystyrene beads, which have approximately the same density as the air voids; they share the same grayscale, and it is not easy to distinguish them, which makes it challenging to characterize the porous 3D structure of this material. The 3D visualization software "Avizo" enabled the 3D reconstruction of the composite and its microstructural characterization. Several microstructure parameters were explored and characterized quantitatively, including porosity distribution, pore surface area, representative elementary volume (REV), sphericity, pore equivalent diameter, and pore network model. The results demonstrated that X-ray micro-tomography is a valuable instrument for non-destructive and complete detection of the microstructural properties of polystyrene reinforced composite.

This study examines the flexural behavior of cellular beams in the context of the size and placement of web openings. Cellular beams are widely used in construction due to their advantages such as weight reduction and versatility. However, the diameter and spacing of web openings significantly impact the flexural capacity of these beams. Therefore, the flexural behavior of steel beams with various web opening diameters and spacings was investigated using both experimental and numerical methods. In the experimental work, four-point bending tests were conducted on steel beams with three different web opening diameters (137 mm, 148 mm, and 160 mm) and various spacing configurations. The numerical analyses were performed using nonlinear finite element analysis in ABAQUS software. The numerical models were validated against experimental results and subsequently utilized in a parametric study. The results showed that increasing the web opening diameter reduced the flexural capacity by up to 64%, while wider spacing increased it by 10-20%. Additionally, when the ratio of beam height to web opening diameter is 1.75, the beam exhibits the highest load capacity and the lowest energy absorption loss. These findings underscore the importance of optimizing web opening configurations in the design of steel structures, both in practical and theoretical terms. The study highlights the need for future research to refine current design codes and integrate new technologies to achieve more efficient designs.

At this time the timber with good quality has been difficult to obtain, so the wood is increasingly rare for building construction. To reduce deforestation due to logging for construction materials, it is time to replace wood with bamboo. Laminated bamboo is an engineering building material that has a character like wood. Laminated bamboo structures can encourage the replacement of wood, steel and concrete materials so that the development of laminated bamboo technology can revolutionize the use of bamboo in construction. One of the weaknesses of the laminated bamboo beam structure is the adhesive line between the bamboo lamina. Mechanical lamination using a shear connector prevents horizontal slip between the bamboo lamina. Incising method is a method that makes the adhesive as well as the adhesive as well as the shear connector. Dendrocalamus asper research material with an average age of 4 years. The testing shear strength and tensile strength of bamboo block lamination was carri...

The use of plant ash as a sustainable cementitious material in concrete composition is a widely researched subject in the construction domain. A plant studied so far more for its thermal insulation properties, sunflower, was analyzed in this study with regard to its ash effects on the concrete composition. The present research aimed to analyze the effects of a 2.5%, 5%, 7.5%, 10%, 15%, 20%, or 30% volume replacement of cement by sunflower stalk ash (SA), a sustainable cementitious material, on the concrete compressive strength at 28 days and three months, the flexural and splitting tensile strengths, the resistance to repeated freeze–thaw cycles, and the resistance to chemical attack of hydrochloric acid. The elementary chemical composition of the SA and the composites was included also. According to the experimental results, SA decreased the values of the compressive and tensile strength of the concrete, but it improved the concrete behavior under repeated freeze–thaw cycles and un...

A natural polymer composite (NPC) was developed from a palm decanter cake (OPDC), and its properties were determined. Oil palm decanter cake natural polymer composite (OPDC-NPC) samples were produced at different ratios of polypropylene (PP) and OPDC before being subjected to flexural, tensile, and water absorption tests. The results showed that by increasing the OPDC content from 5 to 15%, the rigidity as represented by the flexural strength and tensile strength increased from 29 to 43 MPa and 12 to 21 MPa, respectively. However, the flexural modulus decreased from 2230 to 1365 MPa and the water absorption rate increased from 0.16 to 0.44% because of the hydrophilic nature of the OPDC material. The rigidity of OPDC-NPC can thus be improved by increasing the OPDC content from 5 to 15%.

Curtain wall design commonly uses insulating glass units for vision and spandrel glazing to provide better visual harmonization of building facade glass. Risks with this design approach include higher thermal stresses, especially when low-emissivity coatings are used on insulating glass units in spandrel areas. Ceramic enamel frit – commonly used to opacify spandrel glass – is known to induce a bending strength reduction of up to 50%. The ability of ceramic enamel frit coated glass to resist thermal stress is similarly reduced. Multiple incidences of thermal stress related fracture have occurred with heat-strengthened, ceramic enamel frit opacified spandrel glass. An increased chance of spontaneous breakage, by nickel sulfide inclusions, may occur if ceramic enamel frit opacified spandrel glass is fully-tempered to withstand the thermal stresses that it is exposed to. Silicone spandrel glass coatings have been examined as a solution to prevent the strength reduction in heat-treated ...

The new production of Reactive Powder Concrete (RPC) has become an interesting topic due to the dramatic properties that such materials can give. Thus, this study has been prepared to observe the properties of RPC mixes reinforced with micro steel fibers (MSF) by the order of 2% volumetric fractions (vol.). As well, hybrid fibers from MSF, sisal fiber (SIF), and also human hair fibers (HHF) have been included in the RPC mix in the order of 1.5% MSF plus 0.5% SIF, 1.5% MSF plus 0.5% HHF, and 1.5% MSF plus 0.25% SIF plus 0.25% HHF, respectively. Besides, the inclusion of two different nanomaterials combination by 2.5% Nano glass powder (NG) and 2.5% Nano Iron slag powder (NS) was performed into that reinforced RPC. The preparation of these different RPC mixes was followed by testing them to investigate the performance of such RPC based on the properties of flowability, compressive strength, tensile strength, flexural strength, flexural toughness, and static modulus of elasticity. The results showed that the incorporation of 2%MSF increases the compressive strength, tensile strength, and flexural strength by 6.76%, 12.45%, and 14.34%, respectively, at 90 days. Whereas, the reinforcing of RPC by 1.5% micro steel fibers (MSF) with 0.25% sisal fibers (SIF) and 0.25% human hair fibers (HHF) rises the values of compressive strength, tensile strength, and flexural strength by 5.38%, 11.59%, and 14.05%, respectively, at age of 90 days. Moreover, the uses of nanoparticles as 2.5%NG with 2.5%NS in addition to 2%MSF increase the compressive strength, tensile strength, and flexural strength by 33.09%, 36.05%, and 43.68% at age of 90 days, respectively. The use of 1.5% MSF plus 0.25% SIF plus 0.25% HHF with the mentioned nanoparticles (2.5%NG and 2.5% NS) boosts the best performance by converting such concrete from brittle material to ductile material.

─ Two fly ash samples (one from UK, UKFA, and another one from South Africa, SAFA) were washed with water and 1 M hydrochloric acid (followed by water) prior to incorporation (at 65 % wt) into polypropylene homopolymer, containing an unsaturated carboxylic acid coupling agent (Lubrizol Solplus ® C800) with dicumyl peroxide free radical initiator. Melt blending was achieved using a Haake Rheomix 600 mixing chamber and composite test plaques were compression moulded. Flexural and impact testing was then carried out. Unwashed and water washed fly ash based composites responded well to C800 modification and flow micro-calorimetry (FMC) and diffuse reflectance FTIR (DRIFTS) studies confirmed strong interaction between C800 and fly ash. However, washing the fly ash with HCl led to a reduction in composite flexural and impact properties. SEM imaging of the latter composite fracture surfaces revealed poor filler-matrix adhesion, which was thought to be due to reduced interaction between C800 and HCl washed fly ash. The latter was confirmed using flow micro-calorimetry. Reduction of C800 / fly ash interaction led to a reduction in the nucleation of PP crystallisation and a decrease in melt flow rate. The latter may be due to a shift in locus of PP -C800 addition reactions from the interfacial region to the bulk matrix.

This study investigates the use of ceramic waste as a partial replacement for natural aggregates in concrete, to enhance sustainability while preserving structural and economic performance. Concrete mixes were prepared with ceramic waste substituting 0%, 25%, 50%, 75%, and 100% of coarse aggregate by weight. Mechanical propertiesincluding compressive, tensile, and flexural strength-were evaluated, along with durability under sulfate/chloride exposure and 56 freeze-thaw cycles. Statistical analysis using one-way ANOVA confirmed the significant influence of ceramic content on concrete performance (p<0.05), with the 25% replacement mix achieving optimal strength and durability. A life-cycle assessment (LCA) demonstrated environmental benefits, including reductions of up to 25% in global warming potential and cumulative energy demand compared to conventional concrete. Furthermore, a life-cycle cost (LCC) analysis revealed a total cost reduction of approximately 45-50% over a 60-year service life, driven by lower raw material costs, improved durability, and reduced maintenance needs. These findings establish ceramic waste concrete as a technically viable, economically favorable, and environmentally responsible material for sustainable infrastructure applications.

The introduction of asphaltic concrete in Malaysia has brought with it the problem of a through design process of the mixture composition and subsequent extensive control testing that are required to produce and lay the mixture to the required tolerances. however, It is unfortunate to note that many elements of the design, production and construction of the delicate mixture have been either blatantly ignored or manipulated by the contractors and the supervising consultants. while it is clearly stated in pwd guidelines that the initiation and execution of quality control testing must be not left to the contractor, It is a common practice in malaysia to let the contractor carry out most or all the testing as a means to control the quality of the materials and construction works.Verification of test results by the supervising consultants is usually done on the basis of more or less effective surveillance, often by site staff with little or no training and experience. as such. PWD is in...

Propargyl substituted novolac phenolic resin diluted with unsaturated bisphenol-A ethers was used for glass fiber solvent-free impregnation for the formation of high-performance composites. The addition of 20% mass of diallyl (DAEBA) or dipropargyl (DPEBA) bisphenol-A to propargyl substituted novolac phenolic resin resulted in viscosity drop from 2000 mPa•s to 400-500 mPa•s at 140 °C. This proved to be enough to achieve complete impregnation of the twisted glass fibers, as illustrated by SEM analysis. This improvement in impregnation was shown to result in increasing both flexural strength and modulus of the unidirectional glass fiber composite material approximately with a factor of two compared to the composite impregnated with resin without bisphenol-A ethers. DPEBA was shown to be more suitable for high-temperate applications since its addition does not seem to result in a decrease of the heat deflection temperature (HDT).

Abstrak Analisa Serat Pelepah Pisang dan Enceng Gondok sebagai Penguat Komposit terhadap Uji Tarik Oleh : Kunarto Material logam pada berbagai komponen produk semakin berkurang, oleh karena itu banyak dikembangkan material komposit yang mempunyai sifat yang sesuai dengan karakteristik material logam. Salah satu material yang banyak dikembangkan saat ini adalah komposit. Komposit yang digunakan pada penelitian ini dari serat pelepah batang pisang dan enceng gondok dengan campuran yaitu 19% serat enceng gongok, serat pelepah pisang 19% dan resin 62 % untuk varias arah serat horizontal, vertikal dan araj serat silang. Penelitian ini bertujuan untuk mengetahui kekuatan tarik serta untuk mengetahui jenis patahan dengan pengamatan Universal Testing Machining (UTM). Dari hasil uji tarik tegangan-regangan terdapat kekuatan tarik yang optimal pada spesimen serat vertikal 21, 51 (N/mm2), serat arah horizontal 7,57 (Nmm2) dan arah serat silang (24,15 N/mm2) Pada pengamatan UTM terlihat bahwa f...

Perkembangan ilmu material pada hakikatnya terus berkembang seiring dengan memanfaatkan pengolahan bahan dan teknologi. Salah satu aspek yang perlu dipertimbangkan dalam mendapatkan material baru adalah pemanfaatan bahan yang berasal dari tumbuhan atau organik. Salah satu material yang dapat terbuat dari bahan organik adalah komposit. Pohon pisang dan eceng gondok tumbuh dan tersebar hampir di seluruh provinsi di Indonesia namun pemanfaatan sangat kecil bahkan banyak yang tidak dimanfaatkan sama sekali. Sedangkan serat pelepah pisang dan eceng gondok memiliki potensi untuk dimanfaatkan menjadi bahan penguat komposit. Penelitian ini bertujuan untuk mengetahui hubungan antara arah susunan serat terhadap kekuatan tarik dan lengkung (bending). Dalam penelitian ini serat pelepah pisang dan eceng gondok dilakukan perlakuan alkali 5% selama waktu 2 jam. Sedangkan resin yang digunakan adalah epoxy, dengan volume serat pelepah pisang 19%, serat eceng gondok 19%, dan resin 62% dengan variasi ...

Hybrid boards consisting of a strand core and particleboard faces (PSP) with three different shelling ratios were designed using strand sizes from dust to 4.5 mm mesh and normal particleboard face material. Flexural properties, internal bond (IB) strength, screw withdrawal resistance (SWR), hardness, and dimensional properties were measured. The modulus of elasticity of these hybrid boards was 25% greater than that specified by the ANSI standard for M3 industrial particleboard. An increase in modulus of rupture of approximately 50% was recorded for boards containing 60% strands compared with control particleboard without strands. Hybridization also accounted for a decrease in linear expansion compared with particleboard. However, IB strength decreased and SWR values showed no significant change. Therefore, with improved core properties, PSP has the potential to replace M3 particleboard.

Hybrid boards consisting of a strand core and particleboard faces (PSP) with three different shelling ratios were designed using strand sizes from dust to 4.5 mm mesh and normal particleboard face material. Flexural properties, internal bond (IB) strength, screw withdrawal resistance (SWR), hardness, and dimensional properties were measured. The modulus of elasticity of these hybrid boards was 25% greater than that specified by the ANSI standard for M3 industrial particleboard. An increase in modulus of rupture of approximately 50% was recorded for boards containing 60% strands compared with control particleboard without strands. Hybridization also accounted for a decrease in linear expansion compared with particleboard. However, IB strength decreased and SWR values showed no significant change. Therefore, with improved core properties, PSP has the potential to replace M3 particleboard.

Particle geometry was characterized for particleboard furnish prepared through hydrolysis of finished commercial particleboard procured from six Canadian plants. Particles samples were screened into seven particle size classes. Particles retained on 0.5-mm mesh were considered core particles and further partitioned into core-fine, medium, and coarse. Individual particles were then randomly selected for geometrical characterization and distribution fitting. About 80% of all screened particles by mass were between mesh sizes of 0.5 and 2 mm. There were significant differences in percentage screen masses of all particle sizes between plants. Masses of particle size greater than 1 mm of panels from two plants were significantly higher than the rest (0.05 a-level), whereas another plant had the highest mass of particle sizes retained on the 2-mm mesh. Particles retained on the 1-mm mesh showed the largest percentage mass variation among all plants. It was found that aspect ratio was a better geometrical indicator for predicting screw withdrawal resistance than any of the absolute dimensions, and increase in core-fine particles increases internal bond strength. Based on maximum likelihood and Akaike's Information Criterion, a log normal distribution was the best fit for all geometrical descriptors of most particle types; gamma and two-parameter Weibull were better fits for length and aspect ratio for most medium particles with gamma being the better of the two.

Concrete admixed with materials with pozzolanic properties helps to reduce micro cracks which is the major problem faced by conventional concrete. Incorporating sawdust ash in concrete helps to produce sustainable and cost effective concrete structures. This investigation focused on partial replacement of cement with sawdust ash in concrete. The physical and chemical properties of sawdust used were extensively explored and characterised. The performance of concrete mixtures was assessed in terms of workability, tensile strength, flexural strength, water absorption. The durability of admixed concrete in acidic and sulphate environment was also assessed. Optimization was carried out using central composite design to generate optimal value and model equations for the responses. The preliminary study showed that sawdust ash had enough silica content which can help in strength development of concrete at later ages. The consistency of cement was 29% and increased with increasing sawdust ash content. From the results of numerical optimization, the optimum tensile strength of 2.69N/mm 2 , flexural strength of 7.69 N/mm 2 and water absorption of 1.33% were obtained at 10% SDA content and 56 days curing. It was evident that sawdust ash concrete absorbs more water compared to control specimens and also the strength of SDA concretes immersed in sulphate and acidic solutions have 50%MgSO 4 , 90%HNO 3 23%Na 2 SO 4 lower compressive strengths than the control cubes immersed in water only. The research recommends that research should be carried out to evaluate the effects of more supplementary locally available materials in binary and ternary mixture with SDA.

Cracks in concrete expand easily upon application of loads leading to its brittle failure. Fibers are used in concrete to prevent cracks formation. Copper wire has very slow corrosion, better mechanical properties, and ductility than most steel fibres. This paper studied the postcracking behaviors of waste copper wire fibre (WCWF) reinforced concrete. The fibre contents were varied from 0 to 1.5% at an interval of 0.5% by weight of cement. The parameters tested were the toughness, residual strength factors, and equivalent flexural strength ratio. The loaddeflection relationship revealed that the resistance to deformation of the concrete increases with an increase in WCWF. The toughness indices increased with an increase in WCWF contents. Toughness indices of 2.7, 4.3 and 7.0 were obtained for I5, I10 and I20 at 1.5% WCWF content respectively, which fall within the ranges specified by ASTM C 1018. The residual strength factor, R5,10 increased from 16 at 0.5% to 32 at 1.5% WCWF content. Also, R10,20 values of 18, 28 and 27 were obtained at 0.5, 1.0 and 1.5% WCWF respectively. The toughness at net deflection increased by 33.4% and 60.3% respectively. An equivalent flexural strength ratio of 56.71% obtained at 0.5% WCWF content implies that there is a post-peak flexural strength of 56.71% of the flexural strength at 𝐿 150 ⁄ deflection. It is recommended that up to 1.5% of WCWF can be incorporated in the concrete to improve the resistance to deformation and energy absorption capacity of the concrete.

The purpose of this study was to examine the influence of fast sintering on the optical properties, fracture strength, and microstructure of monolithic zirconia (MZ) ceramics. After 20 disc-shaped and 4 square-shaped samples from the MZ block were machined in the CAM device, groups were created by the sintering procedure in accordance with the manufacturer's recommendations: Standard (Grup S; disc-shaped n = 10 square-shaped n = 2) and fast (Grup F; disc-shaped n = 10 squareshaped n = 2). Then, hydrothermal aging was applied to all samples. To calculate translucency, opalescence, and fluorescence values, the LabCh color data of the samples were defined using spectrophotometers. The disc samples were biaxially fracture tested, and the values were determined. The chemical content, grain size (GS), and phase composition of the square-shaped samples were analyzed, respectively. Since the grain size did not conform to the normal distribution, the Mann-Whitney U test was used for statistical analysis, and all other variables were analyzed by an independent sample t test (α = 0.05). The sintering procedure affected translucency, opalescence, fracture strength, and GS significantly (P < 0.05), but not fluorescence (P > 0.05). While both groups had similar crystal structures, there were some minor differences in chemical content. All samples had a higher fracture strength than the ISO 6872 standard recommends. The sintering procedure had no clinically significant effect on the optical properties of MZ. The fast sintering procedure of MZ can be recommended.