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The present paper aimed to experimentally investigate the effect of micro steel fibers (MSF) on the structural shear behaviour of SCC deep beams made of 100% RA. Flexural test were performed on six simply supported deep beams under a single-point loading scheme at shear span to effective depth ratio (a/d) of 1.2 and 1.5. Two SCC beams were made of natural aggregates (NA) without MSF, two beams were made of a 100% RA without MSF, and the last two beams were made of RA with MSF at a volume fraction (vf) of 1%. The parameters considered in this research included load deflection response, ultimate shear failure load, and cracking pattern. The obtained results indicated that using RA considerably reduced the shear capacity of reinforced SCC deep beams in comparison with control mix, and that reduction was more pronounced when a/d ratio was decreased. At a given shear load value, the deflection of RA-based beams was higher than that of NA-based beam, regardless of a/d ratio. This clearly reflected the inferiority of RA particles. However, a comparable or even superior shear strength can be reached when up to 1% MSF was added. Based on this experimental investigation, it was demonstrated that the crack patterns of SCC deep beams prepared with NA, RA, and even MSF, were generally identical. Nevertheless, the crack width for beams with a/d of 1.5 seemed to be more visible than that of a/d of 1.2. [ABSTRACT FROM AUTHOR]

The NSM technique has been used as a contemporary method to fix flaws in structural parts and improve their flexural and shear strength. For this method to work, a number of practical experiments were carried out to understand the behavior of the component that was fortified using the NSM technique for flexure and shear. This research presents an experimental study on the shear behavior of lightweight reinforced concrete (LWRC) beams strengthened in shear by NSM glass fiber reinforced polymer (GFRP) bars. Six LWRC beam specimens with a cross section dimension of 160 mm x 250 mm and a total length of 1700 mm were used in the experimental testing. The control specimen was an un-strengthened LWRC beam, whereas the other five beams were shear-strengthened using various numbers and configurations of NSM GFRP. The spacing, inclination angle, and diameter of the NSM bars used in the strengthening of the LWRC beams are the primary characteristics evaluated in the experiment. All LWRC beams are subject to two point loads until failure. The load-displacement curves, crack patterns, and failure modes of all RC beam specimens were monitored, recorded, and evaluated in this study. Results have shown The sample SG6 (150mm) 45° showed the highest increase in the ultimate load of the strengthened beams, reaching 149% compared with the control beam, while the sample SG6 (300mm) 90° showed the lower increase in the ultimate load of the strengthened beams reaching 38.5% compared with the control beam. The results also showed that GFRP bars work to improve the shear strength of test samples that were strengthened using the traditional NSM method. [ABSTRACT FROM AUTHOR]

The purpose of this research is to conduct an experimental examination of the behavior and failure of deep reinforced concrete (RC) beams reinforced with near surface mounted (NSM) glass fiber reinforced polymer (GFRP) bars. In the experimental testing, ten RC deep beams with cross-sectional measurements of (400160) mm and a total length of (1500) mm were used. The beams were strengthened with NSM GFRP bars in a variety of strengthening configurations, with one beam specimen left unstrengthened as a control. Two loading points were applied to all RC deep beams until failure at various shear spans and effective depth ratios (a/d). The effects of GFRP bar diameters, spacing, and inclinations on the performance of reinforced deep beams were investigated and addressed. The test results revealed that the ultimate strength of strengthened beams increased significantly. Furthermore, more specialized strengthening techniques increased ductility while decreasing diagonal crack width. [ABSTRACT FROM AUTHOR]

Reinforced concrete deep beams are commonly used in high-rise buildings to support heavy loads. Openings are typically given in deep beam construction for accessibility and to permit essential services such as power, ventilation, and network system access. However, deep beams' openings can generate various beam behaviour problems, including reduced beam strength, excessive cracking, and deflection. This investigation conducted the behaviour of longitudinal circular opening-reinforced self-compacting concrete deep beams. The behaviour of six specimens have been studied in this research; different longitudinal circular sizes openings (circular opening in the tension zone with a diameter of (4in, 3in, 2in, in addition to the ratio of the void) were utilized in this study, all specimen have the same dimensions ((1600)mm length, (425)mm total height, and (250mm) width), For comparison purposes, one of these specimens was cast with a solid section (without longitudinal opening). The study's primary consideration is longitudinal openings, size of openings, voiding ratio and openings reinforcement. The crack pattern, deflection, and load capacity were measured and discussed. The experimental program reveals that longitudinal openings reduce the loading capacity of SCC reinforced concrete deep beams; increasing the opening size also lowers the capacity load. The small circular opening's structural behaviour approximated that of the reference specimen. The use of steel pipes to strengthen the longitudinal opening was found to be a practical specimen in increasing deep beam stiffness and load carrying capacity; the ultimate load was enhanced by (12.33) per cent over an unreinforced opening beam. [ABSTRACT FROM AUTHOR]

The features of the assessment of the bearing elements technical condition are considered. The necessity of examining ceilings and beams in an unfinished building, which has a long-forced break in construction, is substantiated. In practice, it became necessary to determine the suitability of a building for normal use after damage resulting from downtime. For this purpose, monitoring of the technical condition of the ceilings and beams of the building was carried out using methodological and instrumental equipment for the inspection of building structures. The results of inspection of structures and reinforcement of ceilings and beams are considered. In accordance with the current regulatory documents, the reinforcement system was checked, and the strength of the concrete ceilings and beams was calculated. The list of defects and damages is taken into account when carrying out verification calculations of reinforced concrete ceilings and beams. Measures and recommendations for the repair of reinforced concrete ceilings and beams are proposed, conclusions about the bearing capacity of structural elements are drawn. [ABSTRACT FROM AUTHOR]

Concrete is the largest contributor to carbon emissions in the construction sector. However, recently there have been no studies analyzing embodied carbon in normal concrete with specific reviews on one structural element and reinforced concrete buildings with variations in structural configuration. The purpose of this study is to determine the influence of material variables and designs of reinforced concrete beam and reinforced concrete buildings on the value of embodied carbon which can then be used as a consideration of low-emission building design. This research was conducted using parametric analysis methods using Building Information Modeling-based applications and ICE Cement, Mortar, and Concrete Model – V1.1 Beta. Reinforced concrete beam were designed with single reinforcement with minimum and maximum reinforcement ratio and in cross-sectional dimension ratios, namely 1:3, 1:2, and 2:3. Reinforced concrete buildings were designed with 3 variations of column elevation, namely 3000 mm, 3500 mm, 4000 mm, and 3 variations in beam span, namely 3000 mm, 4000 mm, 6000 mm. The results of this study show that the greater the ratio of width to height of the beam (b/h) and the reinforcement ratio, the higher the embodied carbon produced. The denser and higher the elevation of the column used, the greater the embodied carbon produced. In reinforced concrete buildings, the cradle-to-gate stage produces embodied carbon by 49.69%, the construction stage by 2.93% and End of Life by 4.39%. [ABSTRACT FROM AUTHOR]

High-Strength Self-Compacting Concrete (HSSCC) is a type of concrete with superior mechanical material properties and the capacity to self-compact without using a vibrator. Many innovations have been performed to improve the characteristics of HSSCC. In the previous experimental work, the authors examined the mechanical properties of HSCC with 12.5% metakaolin and 0-15% silica fume as a partial substitute for cement. Since metakaolin and silica fume have smaller particle sizes than cement, they can fill voids between aggregate and increase the concrete density. Further research at the structural level is required to obtain a more comprehensive understanding of the effect of partially replacing cement with metakaolin and silica fume. The present study analytically investigates the flexural behaviour of reinforced HSSCC beams using the Response 2000 program. As simulation input data, laboratory-determined mechanical properties of the material were utilized. In this study, five beam models constructed with different material mechanical properties were evaluated and compared to each other in terms of flexural cracking strength, ultimate strength, deflection, and crack patterns. [ABSTRACT FROM AUTHOR]

The use of fly ash as a partial replacement for cement in concrete production is one solution to reduce the effects of global warming. In this context, HVFA-SCC concrete is a type of environmentally friendly concrete with advanced technology. However, the use of SCC concrete still faces challenges, such as the lack of aggregate interlock effect that can reduce the shear strength of concrete beams. Therefore, this paper examines the behavior of 100x185x1300 mm HVFA-SCC concrete beams with the use of fly ash as a substitute for cement at 50% of the total binder weight. Beam testing was conducted using a four-point loading system on three test beams. The results of the beam tests showed the formation of initial diagonal tension cracks and primary diagonal cracks at loading of around 30% and 95% of the ultimate shear load, respectively. After the primary diagonal cracks formed, crack propagation rapidly occurred and triggered the failure of the concrete beam shear. [ABSTRACT FROM AUTHOR]

Long-term deflection is the deflection occurred as a function of time and is influenced by several factors such as humidity, temperature, treatment conditions, stress-strength ratio, age of concrete, and so on. This study aimed to analyze the long-term deflection of reinforced concrete beams with onyx waste aggregates and normal aggregates using Gibson R.E & Lo.KY rheological model analysis. The test used reinforced concrete beams with dimensions of 15 x 25 x 200 cm, with a loading duration of two weeks. Based on the results of the experimental tests and the analysis of rheological models, it was found that the deflection value of reinforced concrete beams with onyx stone waste aggregate was greater than that of reinforced concrete beams with normal aggregates. It was indicated by the deflection value obtained from the experimental test for two weeks of loading on the onyx beam of 0.315 cm, and the value of the rheological model prediction was 0.315 cm. The deflection value obtained from the experimental test for two weeks of loading on a normal beam was 0.220 cm, and the value of the rheological model prediction was 0.220 cm. This showed that the results of the rheological model analysis can be used to predict the long-term deflection of reinforced concrete beams. [ABSTRACT FROM AUTHOR]

The main causes of structural failure have been steel reinforcement corrosion of reinforced concrete (RC) structures. Early steel corrosion detection could restrict the cost of the rehabilitation work and minimize the extent and location of required repair or replacement. Of the test of deteriorated concrete beams due to steel corrosion being tested under loading using the non-destructive testing (NDT), i.e., acoustic emission method (AE) is the more efficient method of RC structure evaluation and early corrosion detection. The tests were conducted on corroded beam specimens subjected to cyclic stress before the onset of the initial cracks for a secondary source of AE at the highest load level (i.e., 4 kN). Ib-value and cumulative signal strength (CSS) of AE are recommended to analyze the effects of severe corrosion damage before the initial cracking becomes apparent; as corrosion levels increase, the CSS ratio also increases. It shows that damage caused by a loss in the cross-section of the beams has occurred. [ABSTRACT FROM AUTHOR]

In the practice of designing reinforced concrete structures is more widely used the beam model, so it showed to good advantage for assessing the bearing capacity of the structures. However, in some cases when a more detailed picture of the behavior of the structure is needed the beam model is not suitable by its mathematical nature, which is extremely one-dimensional. The paper deals with numerical approach in developing modern method for calculating of reinforced concrete structures taking into account the elastoplastic characteristics of the material. For more accurate description of behavior under loads it is used the relations for the increment of stresses with the corresponding deformations through the matrix of limiting state, obtained on the basis of the transformation of the certain yield function of the material. The new approach for structure analysis and corresponding algorithms of numerical calculation are developed. It is given an example of determining bearing capacity of reinforced concrete beam, where the results of the solution are compared with the known solutions of structural and solid mechanics. [ABSTRACT FROM AUTHOR]

Beams of reinforced concrete with flanges have been utilized extensively in a lot of applications in structural engineering. The total behavior of this type of member has been studied experimentally and analytically. In this paper, a finite element method-based numerical analysis was used to presented the reinforced concrete's behavior with flanges during the pre-and post-cracking level of loading up to their ultimate stress. Different types of flanged reinforced concrete beams were analyzed, and the results from finite element (F.E.M) were compared with experimental and analytical data. The impact of concrete's compressive strength has been examined. In general, excellent agreement has been obtained between the results of finite element and experimental tests. Also studied numerically is the distribution of concrete longitudinal compressive stresses and tensile stresses along the steel reinforcement. It is found that for high-strength concrete, the ACI Code 318M-14 underestimates the collapse moment of flanged reinforced concrete beams. [ABSTRACT FROM AUTHOR]