In this study, the effect of waste glass on the mechanical properties of concrete was examined by conducting a series of compressive strength, splitting tensile strength and flexural strength tests. According to this aim, waste glass powder (WGP) was first used as a partial replacement for cement and six different ratios of WGP were utilized in concrete production: 0%, 10%, 20%, 30%, 40%, and 50%. To examine the combined effect of different ratios of WGP on concrete performance, mixed samples (10%, 20%, 30%) were then prepared by replacing cement, and fine and coarse aggregates with both WGP and crashed glass particles. Workability and slump values of concrete produced with different amounts of waste glass were determined on the fresh state of concrete, and these properties were compared with those of plain concrete. For the hardened concrete, 150 mm × 150 mm × 150 mm cubic specimens and cylindrical specimens with a diameter of 100 mm and a height of 200 mm were tested to identify the compressive strength and splitting tensile strength of the concrete produced with waste glass. Next, a three-point bending test was carried out on samples with dimensions of 100 × 100 × 400 mm, and a span length of 300 mm to obtain the flexure behavior of different mixtures. According to the results obtained, a 20% substitution of WGP as cement can be considered the optimum dose. On the other hand, for concrete produced with combined WGP and crashed glass particles, mechanical properties increased up to a certain limit and then decreased owing to poor workability. Thus, 10% can be considered the optimum replacement level, as combined waste glass shows considerably higher strength and better workability properties. Furthermore, scanning electron microscope (SEM) analysis was performed to investigate the microstructure of the composition. Good adhesion was observed between the waste glass and cementitious concrete. Lastly, practical empirical equations have been developed to determine the compressive strength, splitting tensile strength, and flexure strength of concrete with different amounts of waste glass. Instead of conducting an experiment, these strength values of the concrete produced with glass powder can be easily estimated at the design stage with the help of proposed expressions.

/pdf/influence-of-replacing-cement-with-waste-glass-on-mechanical-2ew3ba1t.pdf

Influence of Replacing Cement with Waste Glass on Mechanical Properties of Concrete

In this study, the impacts of different proportions of tension reinforcement and waste lathe scraps on the failure and bending behavior of reinforced concrete beams (RCBs) are clearly detected considering empirical tests. Firstly, material strength and consistency test and then ½ scaled beam test have been carried out. For this purpose, a total of 12 specimens were produced in the laboratory and then tested to examine the failure mechanism under flexure. Two variables have been selected in creating text matrix. These are the longitudinal tension reinforcement ratio in beams (three different level) and volumetric ratio of waste lathe scraps (four different level: 0%, 1%, 2% and 3%). The produced simply supported beams were subjected to a two-point bending test. To prevent shear failure, sufficient stirrups have been used. Thus, a change in the bending behavior was observed during each test. With the addition of 1%, 2% and 3% waste lathe scraps, compressive strength escalated by 11.2%, 21.7% and 32.5%, respectively, compared to concrete without waste. According to slump test results, as the waste lathe scraps proportion in the concrete mixture is increased, the concrete consistency diminishes. Apart from the material tests, the following results were obtained from the tests performed on the beams. It is detected that with the addition of lathe waste, the mechanical features of beams improved. It is observed that different proportions of tension reinforcement and waste lathe scraps had different failure and bending impacts on the RCBs. While there was no significant change in stiffness and strength, ductility increased considerably with the addition of lathe waste.

/pdf/improvement-in-bending-performance-of-reinforced-concrete-1ce3zngt.pdf

Improvement in Bending Performance of Reinforced Concrete Beams Produced with Waste Lathe Scraps

In this study, ground glass powder and crushed waste glass were used to replace coarse and fine aggregates. Within the scope of the study, fine aggregate (FA) and coarse aggregate (CA) were changed separately with proportions of 10%, 20%, 40%, and 50%. According to the mechanical test, including compression, splitting tensile, and flexural tests, the waste glass powder creates a better pozzolanic effect and increases the strength, while the glass particles tend to decrease the strength when they are swapped with aggregates. As observed in the splitting tensile test, noteworthy progress in the tensile strength of the concrete was achieved by 14%, while the waste glass used as a fractional replacement for the fine aggregate. In samples where glass particles were swapped with CA, the tensile strength tended to decrease. It was noticed that with the adding of waste glass at 10%, 20%, 40%, and 50% of FA swapped, the increase in flexural strength was 3.2%, 6.3%, 11.1%, and 4.8%, respectively, in amount to the reference one (6.3 MPa). Scanning electron microscope (SEM) analysis consequences also confirm the strength consequences obtained from the experimental study. While it is seen that glass powder provides better bonding with cement with its pozzolanic effect and this has a positive effect on strength consequences, it is seen that voids are formed in the samples where large glass pieces are swapped with aggregate and this affects the strength negatively. Furthermore, simple equations using existing data in the literature and the consequences obtained from the current study were also developed to predict mechanical properties of the concrete with recycled glass for practical applications. Based on findings obtained from our study, 20% replacement for FA and CA with waste glass is recommended.

https://www.mdpi.com/1996-1944/15/22/8093/pdf?version=1669030381

Mechanical Behavior of Crushed Waste Glass as Replacement of Aggregates

In this research, it is studied the crack and flexural behavior of reinforced concrete beams with various bottom ash ratios (BARs) considered as fine aggregate in an experimental and numerical investigation. For experimental purposes, different concrete series are considered varying aggregate sizes ranging from 0 to 25 mm. To supplement concrete, bottom ash is put to use in conjunction with material from 0–5 mm in size aggregate particles as replacement for fine aggregates with ratios of 25%, 50%, 75%, and 100%. Experiments were done to investigate the behavior of the beams and how flexural and fracture behaviors are represented. 75% BARs gave optimum results in terms of displacement capacity. Increasing BAR to 100% decrease deflection capacity of the beam. Also, ANSYS software is used to build 3D finite element models (FEMs) of beams to compare with experiment data. Experimental and 3D numerical tests show exceptionally tight flexural and fracture behaviors. Following this, a computer-generated structure is made by running SAP 2000, and the strength of the beams is then utilised in an RC structural model. Every stage of the building’s construction is thoroughly assessed utilizing multiple types of seismic testing, employing the SAP2000 program, with the resulting analysis providing significant findings on how the seismic force of 75% BAR affects horizontal displacement of each floor. The results showed that the weight of the structure dramatically decreases as the number of columns and RCBs are raised while also increasing the number of BARs. Moreover, the magnitude of earthquake and BAR have a significant effect on the horizontal displacement behavior of reinforced concrete structures. The strength of the concrete structure varies between close- and far-fault earthquakes, and for close-fault earthquakes, concrete strength is stronger than for far-fault earthquakes. This brings us to the second disadvantage of BAR which is the 75% strain produces a severe displacement of reinforced concrete structures. Besides, it was seen that the simulations and experiments yield tiny cracks with very identical configurations.

/pdf/use-of-recycled-coal-bottom-ash-in-reinforced-concrete-beams-15eo3xym.pdf

Use of recycled coal bottom ash in reinforced concrete beams as replacement for aggregate

The performance of waste marble powder as a partial replacement for cement is examined with the aim to achieve more sustainable concrete. Pursuant to this goal, a total of 15 specimens were manufactured and then tested to examine the bending behavior. The effects of longitudinal reinforcement ratio and waste marble powder ratio were selected as variables. The experimental results showed that different proportions of tension reinforcement and waste marble powder had different crack and bending impacts on reinforced concrete beams. As the waste marble powder amount in the concrete mixture is increased from 0% to 40%, it was detected that the crack type changes from a shear crack from to a flexural crack as the amount of waste marble powder increases in the mixing ratio. The experimental findings revealed that the waste marble powder can be successfully used as 10% of the partial replacement of cement. Increasing the waste marble powder ratio by more than 10% can significantly decrease the capacity of the beams, especially when longitudinal reinforcement ratio is high. The influence of waste marble as partial replacement on the capacity decreases as the longitudinal reinforcement ratio decreases. Therefore, 10%–20% marble waste can be utilized as a replacement for cement when the longitudinal reinforcement ratio is close to the balanced ratio and more than 20% waste marble ratio should be avoided for any cases.

/pdf/flexural-behavior-of-reinforced-concrete-beams-using-waste-2gk9it64.pdf

Flexural behavior of reinforced concrete beams using waste marble powder towards application of sustainable concrete

The amount of steel waste produced is on the increase due to improvements in steel manufacturing industries. The increase in such wastes causes significant environmental problems and, furthermore, a large area is also required to store these waste products. Instead of disposing of these wastes, the reuse of them in different industries is an important success in terms of both reducing environmental pollution and providing low-cost products. From this motivation, the effect of lathe scrap fibers generated from Computer Numerical Control (CNC) lathe machine tools on concrete performance was investigated in this study. Pursuant to this aim and considering different fiber content, an experimental study was conducted on some test specimens. Workability and slump values of concrete produced with different lathe scrap fibers were determined, and these properties were compared with those of plain concrete. For the hardened concrete, 150 mm × 150 mm × 150 mm cubic specimens and cylindrical specimens with a diameter of 100 mm and a height of 200 mm were tested to identify compressive strength and splitting tensile strength of the concrete produced with different volume fracture of lathe waste scrap (0%, 1%, 2% and 3%). With the addition of the lathe scrap, the compressive and splitting tensile strength of fiber-reinforced concrete increases, but after a certain value of steel fiber content, there is a decrease in workability. Next, a three-point bending test was carried out on samples with dimensions of 100 × 100 × 400 mm and a span length of 300 mm to obtain the flexure behavior of different mixtures. It has been shown that the flexural strength of fiber-reinforced concrete increases with an increasing content of waste lathe. Furthermore, microstructural analysis was performed to observe the interaction between lathe scrap fiber and concrete. Good adhesion was observed between the steel fiber and cementitious concrete. According to the results obtained, waste lathe scrap fiber also worked as a good crack arrestor. Lastly, practical empirical equations were developed to calculate the compressive strength and splitting tensile strength of fiber-reinforced concrete produced with waste lathe scrap.

/pdf/performance-assessment-of-fiber-reinforced-concrete-produced-39umjc6c.pdf

Performance Assessment of Fiber-Reinforced Concrete Produced with Waste Lathe Fibers

With the increasing number of vehicles in the world, the amount of waste tires is increasing day by day. In this case, the disposal of expired tires will cause serious environmental problems. In recent years, instead of disposing of tire wastes, most of them have been started to be recycled to produce fiber-reinforced concrete. Thus, steel fibers recovered from waste tires have been preferred as an alternative to industrial steel fibers due to their environmentally friendly and low-cost advantages. In this study, an experimental study was carried out to explore the effect of fiber content on the fresh and hardened state of the concrete. To achieve this goal, compression, splitting tensile, and flexure tests were carried out to observe the performance of the concrete with tire-recycled steel fibers with the ratios of 1%, 2% and 3%. There is an improvement in the mechanical properties of the concrete with the increase of the volume fraction of the steel fiber. However, a significant reduction in workability was observed after the addition of 2% steel fibers. Therefore, it is recommended to utilize 2% tire-recycled steel fibers in practical applications. Furthermore, experimental results of concrete with tire-recycled steel fibers were collected from the literature and empirical equations based on these results were developed in order to predict the compressive and splitting tensile strengths.

Özer Zeybek

Papers

Influence of Replacing Cement with Waste Glass on Mechanical Properties of Concrete

Performance Assessment of Fiber-Reinforced Concrete Produced with Waste Lathe Fibers

Mechanical Behavior of Crushed Waste Glass as Replacement of Aggregates

Performance evaluation of fiber-reinforced concrete produced with steel fibers extracted from waste tire

Stress resultants for wind girders in open-top cylindrical steel tanks