Amount Of Reinforcement Research Articles

Electro-magneto-elastic analysis of a sandwich composite beam as diving board in swimming with composed of graphene origami metamaterials

A novel composite structure composed of graphene origami reinforcement integrated with piezoelectric/piezomagnetic layers is defined in this paper. The Material composition is assumed as steel novel metamaterials. The proposed model can be used as a diving board in swimming. The vibrational-based formulation is extended using an advanced higher-order thickness-stretchable model. The governing motion equations are derived using Hamilton’s principle through the computation of strain and kinetic energies as well as external work. The constitutive relations are extended for the composite core in terms of volume fraction, folding degree, and thermal load using some modifier functions using Halpin-Tsai micromechanical models for modulus of elasticity, Poisson’s ratio, thermal expansion coefficient, and density. The natural frequency responses are derived using the analytical method in terms of characteristics of graphene origami such as thermal load, foldability parameter, and amount of reinforcement. Furthermore, an investigation on the impact of initial electro-magneto-mechanical loads is studied on the responses.

Ecological momentary assessment of delay discounting, reward valuation, and craving in very light cigarette users.

Heightened delay discounting has been linked to adverse smoking cessation outcomes, including among light cigarette users. Few studies have evaluated delay discounting's proposed mechanism, preference reversal (concurrent increases in valuation of/craving for desired objects), and none have done so in naturalistic settings. We examined how person-level delay discounting moderated the within-person association between cigarette valuation and craving among very light daily cigarette users who were financially incentivized to abstain. Forty participants completed a baseline delay-discounting task and intermittent ratings of cigarette valuation and craving during the incentivized abstinence attempt. Subjects earned monetary rewards for abstinence on a descending schedule (e.g., $20 on Days 1 and 2 and $2.50 on Days 9 and 10). Consistent with preference reversals, there was a positive association between cigarette valuation and craving. This relation was moderated by delay discounting (stronger among those with low discounting rates) and by monetary reinforcement amount (stronger on days with low reinforcement). Additionally, subjects were more likely to report stronger cravings on days with high monetary reinforcement, with this effect moderated by delay discounting (stronger among those with low discounting rates). The results suggest that heightened delay discounting may not confer risk for preference reversal among very light daily cigarette users who are attempting abstinence.

Production and Characterization of Hybrid Al6061 Nanocomposites

Aluminum-based hybrid nanocomposites, namely the Al6061 alloy, have gained prominence in the scientific community due to their unique properties, such as high strength, low density, and good corrosion resistance. The production of these nanocomposites involves incorporating reinforcing nanoparticles into the matrix to improve its mechanical and thermal properties. The Al6061 hybrid nanocomposites were manufactured by conventional powder metallurgy (cold pressing and sintering). Ceramic silicon carbide (SiC) nanoparticles and carbon nanotubes (CNTs) were used as reinforcements. The nanocomposites were produced using different reinforcement amounts (0.50, 0.75, 1.00, and 1.50 wt.%) and sintered from 540 to 620 °C for 120 min. The characterization of the Al6061 hybrid nanocomposites involved the analysis of their mechanical properties, such as hardness and tensile strength, as well as their micro- and nanometric structures. Techniques such as optical microscopy (OM) and scanning electron microscopy (SEM) with electron backscatter diffraction (EBSD) were used to study the distribution of nanoparticles, the grain size of the microstructure, and the presence of defects in the matrix. The microstructural evaluation revealed significant grain refinement and greater homogeneity in the hybrid nanocomposites reinforced with 0.75 wt.% of SiC and CNTs, resulting in better mechanical performance. Tensile tests showed that the Al6061/CNT/SiC hybrid composite had the highest tensile strength of 104 MPa, compared to 63 MPa for the unreinforced Al6061 matrix. The results showed that adding 0.75% SiC nanoparticles and CNTs can significantly improve the properties of Al6061 (65% in the tensile strength). However, some nanoparticle agglomeration remains one of the challenges in manufacturing these nanocomposites; therefore, the expected increase in mechanical properties is not observed.

Numerical analysis of load-bearing capacity of shear-strengthened reinforced concrete beams without shear reinforcement using side-bonded CFRP sheets

As CFRP (carbon fiber-reinforced polymer) offers high retrofit efficiency for structural members in bending and shear due to its superior mechanical properties compared to steel, sheets made from this material have become ubiquitous in strengthening existing reinforced concrete (RC) structures. However, there needs to be more research on RC beams with no stirrups that have been shear-strengthened with side-bonded CFRP sheets. As such, this study aims to investigate this specific topic and assess design-related parameters that impact the load-bearing capacity of these shear-strengthened beams. To achieve this, nonlinear finite element models of four RC beams, including one control beam and three beams strengthened with side-bonded CFRP sheets, were built and verified regarding shear capacity, crack patterns, and failure mechanisms. The simulated beams demonstrated a high level of accuracy in all mentioned aspects. Numerical models were then developed to evaluate the design-oriented parameters that affect the response of shear-strengthened beams, including the concrete compressive strength, the amount of steel reinforcement, the number of CFRP layers, the CFRP bonding configuration, and the shear span-to-effective depth ratio. The results showed that not only the compressive strength of the concrete but also the amount of steel longitudinal reinforcement had a significant relationship with the load-bearing capacity of shear-strengthened beams. Meanwhile, the bonding configuration and the layer number of side-bonded CFRP sheets considerably influenced the ductility, the crack pattern, and the failure mode of shear-strengthened beams.

Bending Performance of Reinforced Concrete Beams with Rubber as Form of Fiber from Waste Tires

An investigation was conducted to assess the efficacy of using waste rubber as a substitute for a portion of an aggregate to enhance concrete’s sustainability. For the purpose of accomplishing this objective, a total of 12 specimens were constructed and then subjected to a series of tests to investigate their bending behavior. The samples were constructed with the following dimensions: 1000 mm length and a 100 mm by 150 mm cross-sectional area. A few factors were selected, including the impacts of the longitudinal reinforcement ratio and the waste rubber ratio. Based on the volume of aggregates, rubber replacement rates of 0%, 5%, 10%, and 15% were investigated in this study. To assess the beam bending behavior, the stirrup width and spacing were kept constant at ∅6/10. The longitudinal reinforcement was composed of three diameters: ∅6 at the top (for all beams) and ∅8, ∅10, and ∅12 at the bottom. The experimental results demonstrated that the effects of varying amounts of waste rubber and tension reinforcement on the bending and cracking of reinforced concrete beams (RCBs) were varied. The findings indicate that the incorporation of waste rubber into concrete results in a reduction in both the load-carrying capacity and the level of deformation of the material. Additionally, it was shown that as the amount of waste rubber in the RCB increased, the energy absorption capacity and ultimate load decreased. There was a reduction in energy dissipation of 53.71%, 51.69%, and 40.55% for ∅8 when longitudinal reinforcement was applied at 5%, 10%, and 15% replacement, respectively. Additionally, there were reductions of 25.35%, 9.31%, and 58.15% for ∅10, and 38.69%, 57.79%, and 62.44% for ∅12, respectively.

Study on Flexural Performance of Reinforced Concrete Beams Strengthened with FRP Grid–PCM Composite Reinforcement

To study the flexural performance of fiber-reinforced polymer (FRP) grid–polymer cement mortar (PCM)-composite-strengthened RC beams, the finite element numerical simulation of FRP grid–PCM composite RC beams is carried out using ABAQUS to analyze the effects of the amount of FRP grid reinforcement, the type of FRP grid material, and the geometry of FRP grid on the flexural performance of reinforced concrete beams and to establish the flexural capacity calculation formula of FRP grid–PCM-reinforced RC beams in case of debonding failure, based on analysis of the influencing factors. The results show that increasing the reinforcement of the FRP grid and increasing the stiffness of the FRP grid can improve the flexural bearing capacity of RC beams, and the change of FRP grid geometry has little effect on the flexural bearing capacity of RC beams. The established formula for calculating the flexural bearing capacity of FRP grid-reinforced concrete beams can better predict the flexural capacity of reinforced concrete beams under peeling failure.

Seismic capacity evaluation of a reinforced concrete frame infilled with precast modular block wall for enhancing the horizontal load

In this study, we propose a new concept for seismic retrofitting using precast modular block walls (PMBWs) to improve and complement the shortcomings of conventional retrofitting methods for reinforced concrete (RC) frames infilled with shear walls, masonry walls, and precast panels. The PMBW retrofitting method maximizes the advantages of factory-produced modular blocks, innovatively enhancing the constructability and integrity of connections between the existing frame and the infilled PMBW. Additionally, the PMBW reinforcement method improves seismic resistance without significantly increasing structural weight, and the required amount of reinforcement can easily be calculated because the strengthening technique involves typical frame infilling. For RC buildings with non-seismic details dominated by shear failure, the application of this seismic reinforcement method readily ensures sufficient strength. A pseudo-dynamic test was conducted on a full-scale two-story frame, based on an existing RC building with non-seismic details, to evaluate the restoring force characteristics, strength enhancement effects, reinforcement strain, and seismic response control capabilities of the PMBW reinforcement system. Based on the pseudo-dynamic test results, the restoring force characteristics for nonlinear dynamic analysis of the PMBW-reinforced specimen were identified. Finally, nonlinear dynamic analysis was conducted using the proposed restoring force characteristics, and the results were compared with the pseudo-dynamic test results. The unreinforced RC frame experienced shear failure at a design basis earthquake magnitude of 200 cm/s2. However, the frame reinforced with the PMBW sustained only minor damage. Even at higher magnitudes under maximum considered earthquake conditions of 300 cm/s2 and large-scale earthquake conditions of 400 cm/s2, only a slight amount of damage was projected from the analysis. Thus, the newly developed PMBW frame infilling system shows great promise for seismic reinforcement.

Impact of steel tube wall thickness on axial compression behavior of reinforced and recycled aggregate concrete-filled square steel tube short columns

Tests and numerical simulations were conducted to investigate the impact of wall thickness of steel tube on the axial load performance of reinforced and recycled aggregate concrete (RAC)-filled square steel tube short columns (R-RACFST). The test groups consisted of R-RACFST, concrete-filled square steel tube (CFST), and RAC-filled square steel tube (RACFST). Each group had five different wall thicknesses of the steel tube, and the RAC infill was made of 100 % recycled coarse aggregate (RCA). Two replicate specimens were prepared for each group and wall thickness. The tests were used to analyze the effect of steel ratio on failure mode, loading performance, and ductility. The analyses clarified that the reinforcement effectively enhanced the confinement effect on RAC, compensating for the inadequate confinement of the square tubes and the brittleness of the RAC with 100 % RCA. To further understand the acting role of reinforcement, numerical parametric studies were conducted. A novel numerical model for R-RACFSTs was established and verified with the tests. A total of 81 models were then simulated, considering the coupling effects between the wall thickness of the steel tube, the amount of reinforcement, and the strength of RAC. Based on the simulations, the coupling relationship between the steel tube and reinforcement, as well as the optimal range of steel ratio, were determined. Additionally, strength prediction equations were studied and proposed. The findings indicate that it is feasible to fill RAC with 100 % RCA in R-RACFSTs; when combined with appropriate reinforcement, R-RACFSTs with thinner tubes can achieve the same or better performance compared to RACFSTs with thicker tubes; the recommended reasonable range for the steel ratio and corresponding confinement coefficient in R-RACFSTs are 6.4 % to 13.7 % and 1.00 to 2.04, respectively; the predictions proposed are accurate and reliable.

Effects of Ultrasonic Vibration on 3D Printing of Polylactic Acid/Akermanite Nanocomposite Scaffolds

The mechanical properties of 3D-printed scaffolds for load-bearing implantation are crucial. Although the addition of nanoparticles to polymeric matrix scaffolds can improve their mechanical and biological properties, due to certain limitations in printability, high amounts of reinforcement cannot be used. Therefore, in this study, an attempt was made to use ultrasonic (UT) vibration to inhibit nozzle clogging during fused filament fabrication (FFF) of polylactic acid (PLA) scaffolds including 0, 20, and 40 wt.% Akermanite (Ak). Nozzle clogging happened during the conventional 3D printing of PLA-40wt.%Ak, while that did not occur during UT-assisted 3D printing of PLA-40wt.%Ak. Results of X-ray Diffraction (XRD) analysis and Scanning Electron Microscopy (SEM) indicated that applying ultrasonic (UT) vibration had no negative effect on the phases and morphology of the scaffolds. The results obtained by the compression test indicated that applying UT during 3D-printing resulted in almost 27% increment of elastic modulus and almost 25% increase of the compressive strength of the scaffolds. As the conclusion, this study highlights the effectiveness of ultrasonic-assisted 3D printing in producing nanocomposite scaffolds with significantly higher nanoparticle loadings, as compared to conventional printing methods. By utilizing ultrasonic vibration during the printing process, the study showcases the possibility of overcoming viscosity limitations and optimizing the mechanical performance of scaffolds for various biomedical applications, including bone tissue engineering.

Evaluation of the Flexural Behavior of One-Way Slabs by the Amount of Carbon Grid Manufactured by Adhesive Bonding

Fiber-reinforced polymers (FRPs), which are resistant to corrosion, are used as reinforcement material for concrete. However, the flexural behavior of concrete members reinforced with FRPs can vary depending on the properties of FRPs. In this study, the flexural behavior of one-way concrete slab specimens reinforced with a new grid-type carbon-fiber-reinforced polymer (CFRP) (carbon grid) manufactured by bonding pultruded CFRP strands to an adhesive was investigated. The experimental results indicated differences in the load–deflection relationships of the specimens depending on the carbon grid reinforcement amount. Specimens in which the carbon grids were over-reinforced or reinforced close to the balanced reinforcement ratio reached the maximum load due to concrete crushing and exhibited ductile failure. The specimen under-reinforced with the carbon grid exhibited brittle failure. Specimens with carbon grid reinforcement close to a balanced reinforcement ratio exhibited maximum loads ranging from 0.43 to 0.61 times the calculated flexural strength, which resulted in becoming 0.86–1.00 lower in the specimens with a wider width of the CFRP strands. This study proposes coefficients to estimate the stiffness of carbon-grid-reinforced concrete flexural members after cracking. Applying these coefficients resulted in stiffness calculations that reasonably simulated the behavior of the specimens reinforced with carbon grids after crack formation.

Mechanical Properties and Economic Analysis of Fused Filament Fabrication Continuous Carbon Fiber Reinforced Composites.

Additive manufacturing of composites offers advantages over metals since composites are lightweight, fatigue and corrosion-resistant, and show high strength and stiffness. This work investigates the tensile and flexural performance of continuous carbon-fiber reinforced (CCF) composites with different guide angles and number of layers. The cost and printing time analyses were also conducted. Tensile specimens with a contour-only specimen and one CCF layer with a 0° guide angle exhibited nearly comparable strength values. Increasing the number of CCF layers enhances the tensile properties. For the identical cost and reinforcement amount, 0°/0° provides a higher tensile strength and elastic modulus compared with 15°/-15°. The same phenomenon was observed for 15°/0°/-15° and 0°/0°/0°. The samples with one and two reinforcement layers had similar stiffness and maximum load values for flexural tests. For the samples with four layers, there was a considerable improvement in stiffness but a minor decrease in the maximum load.

Influence of amount and delay of reward on choice and response rate: A free-operant, multiple-schedule analogue of a discrete-trial procedure.

The current study explored a free-operant analogue of discrete-trial procedures to study the effects of amount and delay of reinforcement on choice and response rate. Rats responded on a multiple variable-interval (VI) 45-s, 45-s schedule, with interspersed choice probe trials. Comparison of relative response rates and percentage of choice revealed some discrepancies between the free-operant analogue and discrete-trial procedures. Amount of reward controlled choice behavior when the ratios of delays were similar. When reward delays were more discrepant, delay length controlled choice behavior. Whereas the percentage of choice was larger for the larger magnitude reward, the relative rate of response for the larger magnitude was less than .50. In contrast, when the percentage of choice generally fell to below 50% (with large amount and large delay differences between alternatives), relative response rate indicated a preference for the larger amount alternative. This study shows the feasibility and utility of a free-operant analogue of discrete-choice studies that could be used to develop an analysis of preference.

Code-based brittle capacity models for seismic assessment of pre-code RC buildings: comparison and consequences on retrofit

The existing Reinforced Concrete (RC) buildings stock is often characterized by a significant seismic vulnerability, due to the absence of capacity design principles, even in regions with high seismic hazard, such as Italy. Approximately 67% of existing RC buildings in Italy have been designed without considering seismic actions (GLD), resulting in very low transverse reinforcement amount in beams and, particularly, in columns. Additionally, beam-column joints typically totally lack stirrups. Consequently, shear failures under seismic actions are very likely for this pre-code building typology, often limiting their seismic capacity. However, the assessment of shear failures in beams/columns or joints varies significantly from code to code worldwide. The main goal of this work is to quantify the impact of different code-based brittle capacity models on the seismic capacity assessment and retrofit, focusing on GLD Italian pre-1970 RC buildings. This comparative analysis is carried out by first considering three current codes, emphasizing their, even significant, differences: European (EN 1998-3-1. 2005), Italian (D.M. 2018), and American (ASCE SEI/41 2017) standards. Then, shear capacity models prescribed by the current drafts of the next generation of Eurocodes are implemented and compared to the current models. The assessment includes: (i) a parametric comparison among models; (ii) the evaluation of case-study buildings capacity in their as-built condition and after shear strengthening interventions. The latter is performed on 3D “bare” models, due to the lack of practical guidance in most codes on modelling masonry infills.

Seismic Performance of Multistory Reinforced Concrete Buildings by Pushover Analysis

Abstract: In this investigation the analysis of G+4, G+11 and G+21 building is situated in New Delhi (Zone IV. The seismic analysis of of G+4, G+11 and G+21 building as per IS 1893-2002. In this research pushover analysis was performed in SAP 2000 and after that is designed as per IS 456-2000 for different loads. This analysis gives better understanding seismic performance of building & also shows damage or failure of buildings. The building performance level is determined by pushover curve & demand curve. The result shows that the failure is noticed in the column of ground storey of the building. After that enlarged amount of reinforcement in the ground story the buildings have reached life safety performance level.

Evaluasi Desain Struktur Gedung Pondok Pesantren At-Tibyan Deli Serdang

The structural design of this three-story Islamic boarding school building, the results obtained after analysis include; risk category II so that the earthquake priority factor is 1. The soil site class is soft soil. In the structural system, it is designed using a special moment resisting frame system (SRPMK). The seismic design category obtained is category D. Seismic inspection starting from checking irregularities, diaphragm design, checking the number of structural vibration variations, determining the fundamental period of the structure, seismic response coefficient values, seismic base shear, checking the deviation between floors is carried out based on SNI 1726-2019. for column elements, beams and also plates in existing conditions after analysis have met the requirements based on SNI 2847-2019. The conclusion in this final project research is based on the results of the analysis that the design of the Attybian Islamic boarding school building still meets the requirements based on SNI 1726-2019 concerning procedures for earthquake resistance planning for buildings and non-buildings and also for beam, column and plate elements have met the requirements based on SNI 2847-2019 concerning reinforced concrete structures. However, for the beam elements for the reinforcement requirements, it is still too wasteful so that in this analysis, the amount of reinforcement is reduced because in the planning principle it must be safe and economical.

Mechanical, physical, and biological properties of polycaprolactone/ Mg-doped SrFe12O19 nanocomposite scaffolds for bone tissue engineering applications

Nowadays, the utilization of 3D printing has become common in the construction of composite scaffolds. In this research, the co-precipitation method was applied to synthesize pure strontium hexaferrite oxide (SrFe12O19) and magnesium-doped strontium hexaferrite oxide nanoparticles (Mg–SrFe12O19). The synthesized SrFe12O19 nanoparticles had a spherical morphology with a mean size of 60 nm and magnetization (Ms) value of 54.38 emu/g. The Mg–SrFe12O19 also had a spherical morphology with a mean particle size of 46 nm and a magnetization value of 29.89 emu/g. The produced polycaprolactone composite scaffolds containing different amounts (0, 25, 50, and 75 wt%) of reinforcement were fabricated by the 3D robocasting printing method. Based on the results of the compression test, the 25 wt% addition of the pure SrFe12O19 nanoparticles to the polycaprolactone scaffold increased the compressive strength from 2.87 to 11.68 MPa compared to the 100 wt% pure polycaprolactone scaffold. Furthermore, the polycaprolactone nanocomposite scaffold containing 25 wt% Mg–SrFe12O19 also increased the compressive strength compared to the pure polycaprolactone scaffold to 12.94 MPa. Therefore, the 25 wt% reinforced scaffold was chosen as the optimal sample. The contact angles of the pure polycaprolactone SrFe12O19 and Mg– SrFe12O19 reinforced polycaprolactone scaffolds were 77.17, 68.53, and 35.58°, respectively. The values indicate the significant effect of doping magnesium on the wettability. The degradability of the 3D-printed scaffolds containing 25 wt% of the two different reinforcements was evaluated for 28 days immersing in phosphate-buffered saline (PBS) solution. The results revealed that the degradability was higher for the Mg–SrFe12O19 after 28 days compared to the composite scaffold reinforced by pure SrFe12O19 reinforcement. Moreover, it was shown that the bioactivity and cell adhesion of MG63 cells for the scaffolds reinforced by Mg–SrFe12O19 have increased in laboratory conditions. Based on the MTT test, it was observed that both of the scaffolds were non-toxic. The results obtained in this study, suggest that polycaprolactone nanocomposite scaffolds containing 25 wt% of Mg–SrFe12O19, made by the 3D robocasting printing method, are suitable for bone tissue engineering.

Few-layered graphene/Al-Cu alloy matrix composites: Mechanical, tribological and corrosion properties

Nano-sized graphene incorporated Al-5.5 wt% Cu alloy matrix composites were produced via powder metallurgy. Nano-sized graphene powders obtained via the arc-discharge method were incorporated into Al and Cu powders in varying amounts (0–5 wt%) by applying a high-energy ball milling (HEBM) process for different durations. The consolidated composites were prepared by the succeeding uni-axial pre-compaction and pressureless sintering stages. The as-blended and mechanically alloyed (MAed) powders and bulk composites were comparatively characterized in terms of their physical, thermal, microstructural, tribological, mechanical, and corrosion properties depending on the graphene amount and the duration of mechanical alloying (MA). After 4 h of MA, the starting as-blended powders presented as coarse and discrete particles gained a refined and homogenized microstructure with more equiaxed dimensions. Bulk FLG/Al-5.5Cu (FLG in amounts of 0, 0.5, 1, 2, and 5 wt%) composites are ever-increasing hardness values with rising graphene as 109, 101, 128, 238, and 263 HV, respectively. The compressive strength improved gradually to 495 MPa using graphene up to 1 wt%, though contrary to the high hardness values, a drastic decline was observed by 5 wt% graphene incorporation. Besides, the wear resistance of composites outperformed that of the Al-5.5Cu matrix by incorporating this amount of reinforcement together without a deterioration in the corrosion resistance.

Propiedades de un hormigón de alto desempeño fabricado con un proceso de producción convencional

Among cement-based composites, materials that show a growing interest are the High Performance Concrete (HPC) and Ultra-hi-gh Performance Concrete (UHPC), which are categorized by an effective screening of granular elements, and an elevated quantity of fiber reinforcement [1]. HPC is produced through the particle packing methodology to enhance its matrix density and reduce its porosity [2]. Because of this producing me-thod, this material has a lower water content than conventional concrete, and better me-chanical performance and durability [3]-[5]. It is thus suitable to build several structural elements [6], [7] thanks to its enhanced pro-perties. On the other hand, the manufacture of HPC is not straightforward: expensive raw materials, impact on the environment, labo-rious fabrication and curing tasks [8], [9] are among the most important obstacles to its large-scale use. It is therefore relevant and recommended to simplify its production process. This work present new HPC mixtu-res that are produced in a straightforward manner, without requiring elevated tempe-rature curing conditions, mixers with high power or temperature controlled chambers, as commonly used for current HPC sold in the market. The mixtures described here showed a split tensile strength of 5 MPa, a compressive strength of over 70 MPa, and a virtual packing density of 0.86.

Shear Transfer in Concrete Joints with Non-Metallic Reinforcement

The use of non-metallic reinforcement can significantly reduce the carbon footprint of the construction sector. Mixed structures made out of steel and non-metallic reinforcement should be avoided due to the risk of galvanic corrosion. So far, researchers have been focusing on the load-bearing behavior in the longitudinal direction of the fibers. In this study, the behavior of the fibers in the non-metallic reinforcements is analyzed perpendicular to the fiber orientation. Therefore, a uniaxial shear test on a single bar (uniaxial shear test), as well as a series of push-off tests with reinforcements embedded in the concrete, was carried out. For both experiments, bars made of carbon fiber-reinforced polymers (CFRPs) and glass fiber-reinforced polymers (GFRPs) were investigated. In order to analyze the influence of non-metallic reinforcement in the joint, specimens without reinforcement have been tested as well. Also, the joint roughness and reinforcement ratio of the concrete joint was varied in the tests. The determined transverse shear strengths for the single bar exceed the values of the producer. For the push-off test, high standard deviations occurred, making it difficult to draw firm conclusions. Nevertheless, it is shown that increasing the amount of reinforcement leads to higher ultimate forces. The presented study emphasizes the necessity of further studies of the shear transfer in concrete joints.

RC wall building structures: Comparison of first and second generation Eurocode 8 seismic design and detailing strategies

This study provides a thorough comparative analysis of structural design strategies across different ductility classes and seismic action levels, as outlined in Eurocode 8 provisions. The analysis is carried out for 5- and 10-storey building examples. The research highlights key findings regarding base shear demand, storey displacements, sensitivity coefficients, and other crucial structural performance parameters. Those findings indicate that while buildings designed for DCM and DC3 ductility classes generally exhibit similar base shear values and roof displacements, exceptions arise, particularly in the lower-storey buildings where DC2 demonstrates significantly lower roof displacements. The influence of strut inclination on design bending moments is also noted, underscoring its significance in structural behaviour. Moreover, the study delves into interstorey drift ratio (IDR) demands from analysis, revealing consistent displacement patterns across various structures with notable implications for deflection and stability. Additionally, insights into chord rotation control, sensitivity coefficients, and reinforcement quantities shed light on their behaviour under diverse seismic conditions, aiding in optimising structural design strategies.