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Compared to conventional reinforced concrete (RC) flat-plate systems, post-tensioned (PT) flat-plate systems lack experimental studies on shear strength, and there are no studies that have been analyzed and collected with clear criteria (for example, calculation of effective depth, unbalanced moment, and measured shear strength) about experiments conducted so far. As a result, the current ACI 318-19, Section 22.6.5, for pre stressed members has many restrictions based on the lack of experimental data on the nominal shear-strength equation. In this study, to reevaluate the nominal shear strength of the PT flat-plate system more reasonably and provide a reference for future studies, a total of 120 experimental data on the shear strength of the PT flat-plate system without shear reinforcement that have been conducted so far were recalculated and recompiled with clear criteria (the experimental data consists of 74 interior connections, 41 edge connections, and five corner connections). In addition, the factors affecting the shear strength and the validity of restrictions in the nominal shear-strength equation of ACI 318-19 were analyzed. The factors affecting the shear strength include: 1) method of loading; 2) presence of nonprestressed reinforcement; and 3) reinforcement ratio along the lateral load direction. The restrictions in the nominal shear-strength equation of ACI 318-19 include: 1) [f'.sub.c] [less than or equal to] 4900 psi (34 MPa); 2) [f.sub.pc] [greater than or equal to] 125 psi (0.9 MPa) (in each direction); 3) [f.sub.pc] [less than or equal to] 500 psi (3.5 MPa) (average in the two directions); and 4) it is applicable only for interior connections. Keywords: flat plate; post-tensioned (PT); prestressed; punching; shear strength; slab-column connection.

Portland cement hasplayed a significant role in the construction of major infrastructure and building structures. However, in light of the substantial C02 emissions associated with its production, there is a growing concern about environmental issues. Accordingly, the development of eco-friendly alternatives is actively underway Geopolymer represents a class of inorganic polymers formed through a chemical interaction between solid aluminosilicate powder with alkali hydroxide and/or alkali silicate compounds. Concrete made with geopolymers, as an alternative to portland cement, generally demonstrates comparable physical and dura-bility characteristics to ordinary portland cement (OPC) concrete. Research on the material properties of geopolymer concrete (GPC) has made extensive progress. However, the number of large-scale tests conducted to assess its structural performance is still insufficiënt. Additionally there is a shortage of comprehensive studies that compile and analyze all the structural experiments conducted thusfar to evaluate GPC 's potential. Therefore, this study aimed to compile and analyze a number of bond, flexural, shear, and axial strength tests of GPC to assess its potential as a substitute for OPC and identify its distinctive characteristics compared to OPC. As a result, it is considered that GPC can be used as a substitute for OPC without any structural safety issues. However, caution is needed in terms ofdefkction and ductility, and additional experiments are deemed necessary in the aspect of compressive strength of large-scale members.

Geopolymer, an inorganic polymer material, has recently gained attention as an eco-friendly alternative to portland cement. Numerous studies have explored the potential of geopolymer as a primary structural material. This study aimed to examine the efficacy of geopolymer composites as repairing and strengthening materials rather than as structural materials. Data from 782 bond strength tests and 164 structural tests were collected and analyzed, including those on beams, beam-column connections, and walls. The analysis focused on critical factors affecting the bond strength of geopolymer composites with conventional cementitious concrete, and the structural behaviors of reinforced concrete members repaired or strengthened with these composites. The findings highlight the potential of geopolymer composites for enhancing the resilience and toughness of existing damaged or undamaged concrete structures. Additionally, they offer valuable insights into the key considerations for using geopolymer composites as repair or strengthening materials, providing a useful reference for future research in this field. Keywords: bond strength; geopolymer; geopolymer concrete; rehabilitation; repair; strengthening.

Remodeling aging structures is common to enhance their structural, economic, and functional performance. However, the exceeding of bearing capacity of existing piles caused by increased upper loads due to vertical expansion frequently hinders their revitalization. In this paper, a methodology is proposed to control the demand-to-capacity ratio of existing piles without retrofitting the foundation, which is often accompanied by technical limitations and safety issues. A total of 12 tests were performed on four full-scale specimens, with tendon shape, wall thickness, boundary condition, and construction sequence as variables. Factors affecting load-transfer performance were identified based on test results. The target load-transfer pattern implemented in accordance with the tendon shape was confirmed. To verify the validity of the method, tests using tendon shape and wall thickness as variables were compared with results from finite element analysis. Keywords: external post-tensioning; foundation retrofitting; load-transfer; remodeling; vertical expansion.

Streptococcus pneumoniae is one of Gram-positive pathogen that causes invasive pneumococcal disease. Nowadays, many S. pneumoniae strains are resistant to commonly used antibiotics such as β-lactams and macrolides. 3-Acyl-2-phenylamino-1,4-dihydroquinolin-4-one (APDQ) derivatives are known as novel chemicals having anti-pneumococcal activity against S. pneumoniae . The underlying mechanism of the anti-pneumococcal activity of this inhibitor remains unknown. Therefore, we tried to find the anti-pneumococcal mechanism of APDQ230122, one of the APDQ derivatives active against S. pneumoniae . We performed transcriptomic analysis (RNA-Seq) and proteomic analysis (LC–MS/MS analysis) to get differentially expressed genes (DEG) and differentially expressed proteins (DEP) of S. pneumoniae 521 treated with sub-inhibitory concentrations of APDQ230122 and elucidated the comprehensive expression changes of genes and proteins using multi-omics analysis. As a result, genes or proteins of peptidoglycan biosynthesis and DNA replication were significantly down-regulated. Electron microscopy analysis revealed that the structure of peptidoglycan was damaged by APDQ230122 in a chemical concentration-dependent manner. Therefore, we suggest peptidoglycan biosynthesis is a major target of APDQ230122. Multi-omics analysis can provide us useful information to elucidate anti-pneumococcal activity of APDQ230122.