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• Shear behavior of HFRP reinforced concrete beams without stirrups was studied. • The span-to-depth ratio has significant influences on the shear behavior of beams. • A calculation method was proposed about the shear capacity of FRP reinforced concrete beams without stirrups. This paper investigated the shear behavior of carbon/glass hybrid fiber reinforced polymer (HFRP) bars reinforced concrete beams without stirrups. Seven beams with different span-to-depth ratios were tested under four-point loading. Results showed that the span-to-depth ratio had a significant effect on the shear behavior of the beams. According to the test data in this study and published relevant literature, a database containing 468 specimens was established to conduct an in-depth study of the factors that affect the shear capacity of FRP reinforced concrete members without stirrups. By comparing the predicted shear capacity of specimens according to the existing specifications and models with the experimental results in the database, it was found that the predicted results were relatively discrete. The factors influencing shear capacity considered by the specifications and proposed models are inconsistent, and the influence of the span-to-depth ratio was not taken into account. On this basis, a more comprehensive calculation method that considers the influence of span-to-depth ratio was proposed to predict the shear capacity of FRP reinforced concrete beams and presented better prediction results within the experimental. [ABSTRACT FROM AUTHOR]

• A new LEGO-Inspired cage system is developed. • This cage system can be digitally manufactured and assembled in three steps. • Without deformed ribs, this system performs well in UHPC beams. • Existing design model well predicts the flexural strength. • This new system can significantly reduce the cost and labor intensity. Reinforced concrete is one of the most used structural configurations in the world, but the production of reinforcement cage is a labor-intensive, time-consuming and strenuous task. This study develops a new LEGO-inspired reinforcement cage system that is digitally fabricated through waterjet cutting, which can be assembled in three steps. The experimental program tests two ultra-high performance concrete (UHPC) beams reinforced by this LEGO-cage system, one with smooth surface and one with deformed ribs. Results show that including deformed ribs slightly increase the post-cracking stiffness of the beams while both beams exhibit a post-yielding plateau and a displacement ductility ratio over 8. An existing UHPC flexural model predicts the flexural strength (both yield and maximum strength) of the LEGO-cage-reinforced beams with errors below 4%. A two-dimensional finite element model, which is originally developed for rebar-reinforced UHPC, is found to well predict the load–displacement responses of LEGO-reinforced UHPC beams. A cost analysis reveals that adopting this new cage system can reduce the production cost and manual labor time by over 17% and 86%, respectively. [ABSTRACT FROM AUTHOR]

• Web compression buckling of wide-flange members were investigated with load width as the primary variable. • Specimens subjected to wider patch load demonstrated increase in the buckling strength. • Existing code equations significantly underpredict the strength of the specimens. • Using column buckling provisions for wide load widths provided a reasonable approach. • Tests confirmed that sustained load effects on web compression buckling were insignificant. A comprehensive study on web-compression buckling strength of wide-flange steel members subjected to concentric transverse loads spread over lengths longer than member section depth is presented in this paper. Calculation methodologies previously developed for web-compression-buckling strength of wide-flange steel members were established for use in beam-to-column moment connections, where the load width is relatively very narrow compared to the depth of the section, therefore does not include load width as a parameter in strength equations. More recently developed calculation procedures that account for load widths are typically limited to member section depth and are merely based on numerical models, and lack experimental evidence that validates these models. This study presents experimental research on steel wide-flange members subjected to transverse compression loading by having the load length as the primary variable. Experiments were conducted on specimens with measured imperfection levels and provided results on the buckling strength, displacement, and strain variation of the web portion during testing. The experimental program also investigated the potential of creep under sustained loading on web compression buckling strength of wide flange members at load levels near buckling strength. Benchmark numerical models using the finite element method were developed using the test results to obtain insights into the observed behavior and were employed in conducting numerical parametric studies to investigate the sensitivity of results due to load width and the angle of the applied load for various cross sections. The results obtained from the experimental and numerical studies were compared with the calculation methods provided in the North American and European design codes to evaluate their accuracy. The parametric study results were also used to develop an analytical calculation procedure for estimating the web-compression-buckling strength of steel wide-flange shapes subjected to vertical and inclined loading. [ABSTRACT FROM AUTHOR]

This paper experimentally investigates the effects of corrosion-induced cracking damage on the static behavior of corroded reinforced concrete arch ribs. Four circular reinforced concrete arches including an uncorroded arch rib and three corroded arch ribs are designed and made in laboratory conditions. The initial crack distribution and crack width are discussed by accelerated corrosion test observations. Based on a five-loading static test, the crack propagation, the load–displacement response, the ultimate load bearing capacity and the failure modes of arch ribs are also discussed. Following this, a developed calculation model considering the effect of corrosion damage is used to assess the capacity of the arch ribs. Experimental data are used to validate the proposed method and reasonable agreement is observed between theoretical predictions and experimental results. [ABSTRACT FROM AUTHOR]

Highlights: [•] Stress analysis and heat treatment numerical models combined with crack growth model. [•] Model to predict lifetime strength and failure origin of bolted glass connections. [•] Experimental results used to support model. [•] Results how approach is accurate and support crack healing hypothesis. [Copyright &y& Elsevier]

• Machine-learning-based models are established to predict shear transfer strength of concrete joints. • A database of 512 specimens including various construction details and concrete materials is assembled. • The models are experimentally verified and compared with existing mechanical models. • Parameter study is done to validate the consistency of the models with test results. • The models can provide the predicted results with high accuracy and low error. In predicting the shear transfer strength (STS) of concrete joints, numerous design parameters need to be considered due to diverse application scenarios and various construction materials. Existing mechanical-based models were established only based on limited data or for a specific scenario, leading to their insufficient prediction capability for STS of concrete joints. This research aims to develop a more accurate, stable, and reliable prediction model for STS of concrete joints based on machine learning technology. A database of 512 test results was assembled for the STS of concrete joints. Two machining learning models, the support vector regression (SVR) model and the random forest regression (RFR) model, were determined by a customized training procedure. A new feature selection method was proposed to sort input parameters based on a combined weight value representing influence intensity. The two optimized machine-learning-based models were experimentally evaluated, and further compared with common mechanical-based models through a series of performance indicators. A parameter study was conducted on the most influential parameters using the mechanical-based and machine-learning-based models. Results show that the SVR and RFR models are experimentally verified to be more accurate, stable, and reliable compared with the mechanical-based models. Concrete compressive strength, stirrup contribution, cohesion-related parameter, and fiber volume are recognized to be the most influential for STS of concrete joints, which agree with common mechanical-based models. Parameters like height of the shear plane, height of the top support of the joints, width of the joints, maximum aggregate size, longitudinal bar contribution at the shear plane are also detected to have obvious effects on the STS but are not considered in most of the mechanical-based models. Compared with the RFR model, the SVR model is more recommended for the prediction of STS due to better consistency with experimental results. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this study is to investigate the technical feasibility of using a modal parameter based global nondestructive damage evaluation method to evaluate, quantitatively, welded reinforcement splices during the construction process. For the purpose of this study, an expression which predicts the strength of the weld, in terms of the yield strength of the steel and the effective stiffness change in the weld, is developed. Then, an experiment to nondestructively measure the fractional stiffness changes, using changes in modal parameters and a system identification technique, in the welded region of 27 welded reinforcing bars is performed. For comparative purposes, a conventional nondestructive testing (NDT) method, radiographic inspection, and destructive tensile tests are performed to evaluate the accuracy of the nondestructive strength prediction procedure. The predicted strengths of the weld systems, obtained from the strength–damage models and the nondestructively measured fractional stiffness change, are compared with those from the destructive tensile test. Also, areas for potential improvement for field implementation of the methodology are investigated. [Copyright &y& Elsevier]

• A data-set is compiled of 191 experimental tests available in the literature. • A comparative performance assessment is made of different out-of-plane strength capacity models. • A parametric numerical analysis is carried out. • A novel strength equation is calibrated. • Coefficients to account for the presence of an opening and of a top gap are proposed. A large part of 20th and 21st centuries' residential buildings is characterised by reinforced concrete, or less frequently steel, frames filled with masonry walls. Recent seismic events have shown that failure of infills may occur under moderate earthquakes, inducing a risk to life and limb of occupants, as well as to construction cost of the building. For this reason, researches have been devoted to the capacity of infill walls carrying out both analytical and experimental tests, also in the out-of-plane direction. These studies have identified the main parameters affecting the out-of-plane response of infill, such as the boundary conditions and the slenderness of the infill. In this study, a large data set of experimental tests is collected with the aim of investigating the influence of the main factors relevant for the infill response and to assess the suitability of different formulations proposed in the literature. It is found that, for the most part, such formulations underestimate the out-of-plane strength. Afterwards, numerical analyses are performed to investigate those situations that were scarcely considered in experimental campaigns, namely the presence of an opening (window or door) and of a gap between the infill and the top beam. Finally, taking into account all the considered parameters, a formula to predict the out-of-plane strength capacity of an infill is proposed. [ABSTRACT FROM AUTHOR]