Papers by Keyword: Compressive

Abstract: ’This study investigates the mechanical performance of concrete reinforced with recycled polyethylene terephthalate (PET) fibers obtained from discarded plastic bottles, aiming to promote sustainable waste reuse in construction materials. Previous studies on PET fiber reinforced concrete have mainly examined the influence of fiber length and content separately, without considering their combined effects on mechanical properties. In this work, the interactions between fiber length, volume fraction, and mechanical behavior were systematically analyzed using a Central Composite Design (CCD) within the framework of Response Surface Methodology (RSM). Concrete incorporating recycled PET fibers was evaluated at three volume fractions (0.3%, 0.8%, and 1.3%) and three lengths (20 mm, 40 mm, and 60 mm), while maintaining a constant water-to-cement ratio. Sixty specimens were tested to assess both fresh and hardened properties. The greatest loss of workability occurred for the mix containing 1.3% fibers with a length of 60 mm, corresponding to about a 25% reduction compared with the control. Response Surface Methodology (RSM) based on a Central Composite Design (CCD) identified 0.3% fiber content and 40 mm length as the optimal combination, representing the mix that simultaneously maximized both compressive (26 MPa) and tensile strengths (3 MPa) according to the predictive model.

Abstract: This study examines the impact of Al₂O₃ particles on composites made of sisal and epoxy. A unique combination of hand lay-up and compression molding procedures are used to fabricate the Sisal/Al₂O₃/epoxy hybrid composites, with different weight percentages of Al₂O₃ particles of 0%, 1%, 2%, and 3%. The produced sisal/Al₂O₃/epoxy hybrid composites' flexural, tensile, and compressive properties are then correlated with water absorption studies. The sisal/epoxy composites have undoubtedly been affected by the Al₂O₃ particles, which have improved their mechanical and physical properties. Compared to other composite samples, the sisal/2wt.%Al₂O₃/epoxy hybrid composites show superior flexural, tensile, compressive, and water absorption resistances. Therefore, the optimal combination of hybrid sisal/Al₂O₃/epoxy composites can prominently improve the properties, making them a viable alternative for a variety of industrial applications.

Abstract: AA7050 aluminum alloy with desirable mechanical properties like strength, stress corrosion resistance, and toughness widely used in aerospace applications. In this study AA7050/Al₂O₃/ZrO₂, hybrid composites fabricated with different wt. % of reinforcement materials (0.5, 1, 1.5 wt. % ZrO₂, and 1wt. % Al₂O₃ constant for all composites) by using stir casting process. The SEM image has shown the uniform distribution of the reinforcement particles in the AA7050 matrix with the addition of 1wt% Al₂O₃ and 1wt% ZrO₂ reinforcement. The compressive strength is increased from 9.41% to 10.47% and tensile strength 4.74% to 10.27% for the composite of 1wt %Al₂O₃ and varying 0.5 and 1 % wt ZrO₂ compare to base alloy. From the dry wear studies, the composite with 1wt% Al₂O₃ and 1wt% ZrO₂ have observed minimum wear loss and coefficient of friction at sliding velocity from 1.9896 to 3.9793m/s and at varying load condition from 20N to 60N compared to base alloy.

Abstract: The aim of study is to produce durable structural concrete by using waste ceramics with specified type (white clay ceramics) as coarse aggregates in concrete. Mechanical properties were studied, the study also show good resistance to fire resistance for concrete contains ceramics as coarse aggregates compared with normal aggregates concrete, good mechanical properties such as compressive, tensile, and flexural strength. Results of study gave 17.5% increment in compressive strength by using 100% replacement of waste ceramic, flexural strength increased with 27.8% increment. Study also show less reduction in strength due to fire resistance by using waste ceramics compared to ordinary concrete, and also more durable concrete for salty water effects by using ceramic.

Abstract: Ordinary concrete - a stone like structure which is formed by the chemical reaction of the cement, aggregate and water and is a brittle material which is strong in compression but very weak in tension, which causes cracks under small loads. These cracks gradually propagate to the compression end of the member and finally, the member breaks. These increase in size and magnitude with time and finally fails. One of the successful reinforcing methods is providing steel reinforcement but even then, cracks in reinforced concrete members extend freely. Thus, need for multidirectional and closely spaced steel reinforcement arises. Fiber reinforcement gives the solution for this problem. So, to increase the tensile strength of ordinary concrete a technique of introduction of fibers in concrete is being used. These fibers act as crack arrestors and prevent the propagation of the cracks, improves the post cracking response of the concrete, i.e., to improve its energy absorption capacity and apparent ductility, and crack control. The Present study focuses upon, Synthetic (Polypropylene) Fiber Reinforcement (SFRC) of 1% and 3% and Natural (Jute) Fiber Reinforcement (NFRC) of 1% and 3% by weight and are compared with respect to their compressive strength and flexural strength. The present study concludes considering the practical issue of workability of fibers, that in between synthetic and natural fibers selected, 1% Polypropylene fibers can be added as a reinforcement to ordinary concrete to enhance both compressive strength by nearly 2 times at 28 days curing duration and flexural strength by 35%% at 28 days curing duration. History and Development

Abstract: Residual stress measurements were successfully performed on the representative IN718 fatigue specimens by X-Ray Diffraction. All surface residual stresses were found to be compressive. A stress gradient normal to the surface was observed on all specimens. The residual stresses tended to become less compressive with increasing depth into the parts. Residual stress measurement is the special requirement for NADCAP CRITERIA AC 7101/7. In this paper, residual stress measurements were successfully performed on two IN718 low cycle fatigue test specimens.

Abstract: In this study, the mechanical behavior of white clay based geopolymer filled epoxy composites was studied through compressive test. The morphology of white clay based geopolymer and origin was characterized using scanning electron microscopy (SEM). A series of epoxy composites with various white clay based geopolymer filler loadings varying from 0 to 7phr of was prepared. The assessments showed the presence of white clay based geopolymer in the composite system has improved the compressive properties of the epoxy. This indicated the potential of epoxy / white clay based geopolymer composites in structural applications.

Abstract: The effects of mixing approach on compressive, flexural, water absorption properties and morphology of the epoxy nanocomposites incorporating 0 and 3 wt% fly ash-based geopolymer were investigated. The mechanical stirrer with two different type of propeller; four blade (type A) and dissolver (type B) was used to blend the epoxy with the nanoclay and the fly ash-based geopolymer filler. It was found that the epoxy nanocomposite prepared using dissolver propeller (type B) performed higher compressive strength and higher flexural strength as compared to the one prepared using four blade propeller (type A). We postulate that this was due to an improved mixing efficiency and dispersion quality as observed through Field Emission Scanning Electron Microscopy (FESEM).

Abstract: The combinations of polymer resin and glass microballoon are the main materials used to produce syntactic foams. Syntactic foam is a lightweight material that has good mechanical properties and is commonly used as a component for structural materials in civil construction, aerospace and marine applications. Hence, it should have suitable mechanical properties, particularly good compression behaviour. In the present study, the results obtained from compression tests are compressive strength, elastic modulus and specific compression that decrease when increasing of glass microballoon contents (2.0 wt.%, 4.0 wt.%, 6.0 wt.%, 8.0 wt.% and 10.0 wt.%) and also neat resin. The highest strength value for compression testing is owned by 2.0 wt.% which is 88.9 MPa, while the lowest strength is 43 MPa that belongs to 10.0 wt.% of glass microballoon. This shows that the density and weight percentage of glass microballoon in these syntactic foams affect compression properties. Therefore, a further study should be conducted, which includes the effect of compressive failure mechanism.

Abstract: Based on 75 cube specimens(100mm×100mm×100mm) of the super high early strength grouting material at elevated temperature,this paper describes the design of the high temperature test,compressive test and some relevant phenomena in testing,analyzes strength of the super high early strength grouting material at elevated temperature,and obtains the stress-temperature curves of the super high early strength grouting material at elevated temperature.By analyzing the staged characteristics of the curves,the regularity of the strength of the super high early strength grouting material at elevated temperature is discussed and some fitting mathematical formulas are suggested.